A Metabolic Paradigm Shift, or Why Fat Is the Preferred Fuel for Human Metabolism

There’s a good reason so many people (mostly the sugar-burners, whose disparate group includes fruitarians, veg*ans, HEDers, body-builders, most MDs, the USDA and virtually every RD program in the country) can’t seem to grasp why a lower carb, Primal approach to eating is a better choice for health and fitness: their fundamental paradigm – the core theory that underpins everything else in that belief system – is flawed. They remain slaves to the antiquated notion that glucose is the king of fuels, so they live their lives in a fear of running low. The truth is, fat is the preferred fuel of human metabolism and has been for most of human evolution. Under normal human circumstances, we actually require only minimal amounts of glucose, most or all of which can be supplied by the liver as needed on a daily basis. The simple SAD fact that carbs/glucose are so readily available and cheap today doesn’t mean that we should depend on them as a primary source of fuel or revere them so highly. In fact, it is this blind allegiance to the “Carb Paradigm” that has driven so many of us to experience the vast array of metabolic problems that threaten to overwhelm our health care system.

It boggles my mind that such a large segment of the so-called health and fitness community would continue to defend high carbohydrate diets with such tenacity. It should all be very obvious by now. The studies keep piling up indicating that carbohydrate intake is the major variable in determining body composition and that excess glucose from carbohydrate intake (especially from processed grains and sugars) is the primary culprit in obesity and in many disease processes. It follows logically that if you can limit carb intake to a range of which is absolutely necessary (and even up to 50 grams a day over) and make the difference up with tasty fats and protein, you can literally reprogram your genes back to the evolutionary-based factory setting you had at birth – the setting that offered you the opportunity to start life as a truly efficient fat-burning organism and to continue to do so for the rest of your life as long as you send the right signals to your genes. Becoming an efficient fat-burner is the major premise of the Primal Blueprint eating and exercise strategies.

But logic doesn’t rule when you are stuck in the Carb Paradigm, so I still see some misguided bloggers decrying the Primal Blueprint eating strategy as potentially harmful for its relatively low carb intake or stating that my advice to “generally keep carbs under 150 grams a day unless you’re an athlete” is ridiculous. How many more times do I have to overhear a trainer advising a still-portly client to “eat 5 or 6 small meals throughout the day, always with some carbs, so you keep your blood sugar up and don’t go into starvation mode.”? It’s time to stop this nonsense and reframe the current views of human metabolism to accurately reflect the two and a half million years of evolution that shaped the current human genome – a perfect DNA recipe that fully expects us from birth to function largely on fats.

It’s time for a Metabolic Paradigm Shift within the health and fitness world.

The Faulty Carb Paradigm “Logic” Goes Something Like This

The basic underlying assumption is that glucose is the preferred fuel of most cells; BUT, because we can’t store very much glucose (as glycogen in liver and muscles), we need to provide a continuous source of glucose in the form of exogenous carbohydrate (high carb meals) to keep the brain, blood, and certain organs humming along and the muscles primed for activity. AND, if we don’t feed ourselves enough carbohydrate every few hours, our blood sugar will drop and we’ll go into “starvation mode” and cannibalize our precious muscle tissue. AND any lack of regular glucose refilling (i.e. skipping a meal or fasting) will cause cortisol to rise, which will have additional deleterious effects. FURTHERMORE, an excess of glucose in the bloodstream is known to raise insulin and will predispose excess calories (from all sources) to be stored as fat. THEREFORE, we should also be doing a lot of moderate-to-heavy cardio or lifting activity most days to burn off this excess stored body fat. HOWEVER, if we want to be ready and able to exercise frequently and strenuously to burn off our stored fat, we need to eat lots of complex carbohydrates between workouts to refill our glycogen stores. And ULTIMATELY, the only way to lose weight is to restrict calories (calories in<calories out), BUT if you’re working out regularly, it’s almost impossible to maintain a calorie-restricted regimen and still be able to work out hard enough to burn appreciable calories. Sheesh.

Sure, there are exceptions, like the driven and genetically gifted types, who can train long hours, refuel on carbs and not add much body fat (hey, I was one). But unless you love to work out incessantly and have really lucky familial genes, the Carb Paradigm is an unsustainable and ridiculous literal and figurative treadmill, a self-fulfilling prophecy for most people who tend to gain weight steadily and insidiously over the years and wonder why. If you are one of the 60+% of the American population who is overweight, the above scenario plays itself out because you have spent your life programming your genes in the direction of being an effective sugar burner and, as a result, have become dependent on a fresh supply of sugar (carbs) every few hours. Naturally, in the presence of all that glucose, and provided you actually do some exercise, your genes will eventually get the signals to up-regulate the enzyme systems, pathways and receptors involved in sugar-burning and fat storage and they’ll down-regulate all those involved in accessing and burning fat for energy. Of course, that doesn’t make it right, but it sure makes it appear as if glucose is king. What makes it worse, if you don’t exercise, you head down the path to insulin resistance and/or obesity.

The Problem: The Basic Assumption of the Carb Paradigm is Wrong

Glucose is not the preferred fuel of muscle cells under normal human resting metabolic conditions or even under most normal human movement patterns (exercise). Fat is. Sure, given an unlimited supply of glucose and regular refilling of glycogen stores, skeletal muscle will burn through it during exercise the same way a fire burns through kindling when that’s all you have to offer. The body can shift carbohydrate oxidation to keep up with intake. But skeletal muscle can burn fat with great efficiency (and far less oxidative fallout) at relatively high outputs for very long bouts. Cardiac muscle actually prefers ketones, and the brain can run just fine (maybe even optimally) on a blend of ketones and minimal glucose.  Our survival as a species has depended on these evolutionary adaptations away from glucose dependency. Entire civilizations have existed for ages on what is practically a zero-carb diet. Think about this: there is actually no requirement for any “essential dietary carbohydrates” in human nutrition. It’s possible to live a very long and healthy life never consuming much – if any – in the way of carbs, provided you get adequate dietary protein and fat. The same can’t be said for going too long without protein or fat. Cut too far back on either of those macronutrients and you will eventually get sick and die.

The Evolutionary Model

Fat and protein were the dominant macronutrients (when food was even available) over the majority of our two-and-a-half million years as evolving humans. The lack of regular access to food and a scarcity of carbohydrates for much of this time necessitated that we adapt efficient pathways to readily store and access body fat for energy if we were to survive day-to-day and generation-to-generation. Our movement patterns were such that we never required large amounts of glucose or that we needed to store very much glycogen. It was predominantly fats, ketones and the minimal infusion of glucose via gluconeogenesis that got us here. Dietary carbs were insignificant. In fact, when you consider how ridiculously small the body’s glycogen reservoirs are, you understand that it would have been impossible for us to survive as a species if glucose were truly the “preferred” fuel. The liver, the main back-up glycogen/glucose storage facility for the brain and other glucose-burning organs, can only store about 100 grams of glycogen. Less than a day’s worth. Your muscles can only hold another 350-500 grams, barely enough to run for 90 minutes at a reasonable clip, and that glycogen isn’t even available to provide fuel for the brain. Meanwhile, we have a virtually unlimited storage capacity for fat (like 100,000 grams or close to a million calories on some people). The reason glycogen storage wasn’t necessary is because, between our copious fat storage capability, easy access to fats as fuel, gluconeogenesis and ketones, we just didn’t need much. Evolution tends not to reward structures or functions that take up unnecessary space or waste energy.

So How Much Glucose Do You Really Need?

Much less than most people assume. At any one time, the total amount of glucose dissolved in the bloodstream of a healthy non-diabetic is equivalent to only a teaspoon (maybe 5 grams). Much more than that is toxic; much less than that and you pass out. That’s not much range for a so-called “preferred” fuel, is it? Several studies have shown that under normal low MET conditions (at rest or low-to mid- levels of activity such as walking and easy work) the body only needs about 5 grams of glucose an hour. And that’s for people who aren’t yet fat-adapted or keto-adapted. The brain is the major consumer of glucose, needing maybe 120 grams a day in people who aren’t yet on a low carb eating program. Low carb eating reduces the brain’s glucose requirements considerably, and those who are very low carb (VLC) and keto-adapted may only require about 30 grams of glucose per day to fuel the brain (and little-to-none to fuel the muscles at <75% max efforts). Twenty of those grams can come from glycerol (a byproduct of fat metabolism) and the balance from gluconeogenesis in the liver (which can actually make up to a whopping 150 grams a day if you haven’t metabolically damaged it with NAFLD through fructose overdosing). Bottom line, unless you are a physical laborer or are training (exercising) hard on a daily basis, once you become fat-adapted, you probably don’t ever need to consume more than 150 grams of dietary carbs – and you can probably thrive on far less. Many PBers do very well (including working out) on 30-70 grams a day.

The Fat Paradigm

The Fat Paradigm, under which the human species has thrived quite effectively for two and a half million years, recognizes that human metabolism is pre-programmed by evolution to be primarily fat-based (the real preferred fuel). In other words, our genes expect us to function optimally when we consume fats and can easily access our stored fat. The Fat Paradigm acknowledges that the body is able to manufacture adequate glucose as needed. It acknowledges that most typical human movement patterns can be fueled almost entirely by fats and/or ketones (PDF) if need be, but can draw on glycogen when energy bursts are required (and which can then be replaced over time). It acknowledges that fat (and cholesterol) are not the proximate cause of heart disease. It acknowledges that fat cells are designed to release stored fatty acids as required, especially during times of scarcity or fasting. It allows for intermittent fasting as a means of accelerating fat loss without sacrificing muscle tissue. It increases insulin sensitivity, modulates energy and mood swings, and allows for a normal and healthy drop in hunger and cravings. There is a downside, however: you can’t train long and hard day-in and day-out in the fat paradigm.

Now then, having explained all this, please understand that I am not carb phobic. I actually permit more carbs in the Primal Blueprint than many other low carb eating strategies. I prefer to view carbs as the “elective” macronutrient, as a tool to use to manipulate your glycogen levels as needed. Low carb isn’t even the main objective of eating in the PB: eliminating grains, sugars and seed oils are the primary objective. Of course, when you get rid of that crap and naturally limit your carb intake to veggies, root tubers and a few fruits, you almost invariably decrease carbs to under 150 grams a day. And that emulates our ancestral dietary intake.

I came up with a simple Carbohydrate Curve a few years ago that offers a pretty concise picture of where most people ought to fall if they are seeking optimum health and energy, depending on their size, weight, sex, age, goals, etc. Now, many hundreds of thousands of user experiences later, I am finding that the Curve is pretty much spot on for a large segment of the population.

When I say generally that a chronic intake of over 150 grams of carbs can lead to insidious weight gain over a lifetime, I am factoring in the concept that many people are at the effect of a familial genetic predisposition to storing fat easily under the carb paradigm (the 60+% overweight). I am also factoring in the drop in metabolism that happens naturally with age, as well as the fact that PBers don’t NEED to purge and refill glycogen stores every day via exercise. Yes, there are some people (a small percentage of outliers) who might maintain pretty decent body composition at up to 300 grams a day on little exercise. I would bet that they also are selective about the carb sources and do a better job of controlling overall calories, so there’s little excess to store. For most of the population, that 150 mark remains a good average level for maintaining ideal body composition.

Well, that was a lot to digest today. You see where I’m going with this. I need your help in showing the health community that their basic assumptions are wrong and that they need to make a Metabolic Paradigm Shift. I’m sure there will be lots of specific questions, so bring  ‘em on and I’ll do a follow up post in a week or two.


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About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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557 thoughts on “A Metabolic Paradigm Shift, or Why Fat Is the Preferred Fuel for Human Metabolism”

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  1. Great Post! I was just wondering about how to best use fat as fuel/carb levels etc. As usual, a very concise and informative article. 🙂

    1. PS – just to be honest, although I have been primal for awhile, I haven’t really taken note of carbs. What is the best resource to find out how many are in basic primal foods? Or, can I just assume that limiting potatoes and fruit is a good start?

      1. Fitday, fatsecret, SparkPeople all have food trackers and I think they all plug into the USDA database. If you don’t want to deal with any tracking sites you can just go straight to the database. Google “USDA nutrient database” and you’ll find it.

        If you haven’t got the conversion formulas memorized you might also open a gram to ounce converter in another tab while you’re going through the database to get a better ballpark idea of what serving size you’re looking at, especially if you’re not familiar with the use of metric measures of mass.

      2. I use fitday to track and nutrition data to look up a few foods. Nd includes omega 3 and 6 content.

      3. Crunchy, I started using http://www.fitday.com, and love it. It’s free. I log every bite that I take throughout the day. Each time you look up and log a type of food, it adds it to your personal “recent” foods database, so eventually you won’t be searching for foods anymore.

        I never was a “food-logger”, and found it eye-opening to use this tool. Not only to keep track of calories, but it provides a great pie chart every day to show the percentage of calories from fat, protein and carbs.

        Like Mark has said, I have found that by sticking to mostly leafy greens and colored veggies (in addition to my protein/fat sources), my carbs (on a 2,000 or so per day plan…I am trying to cut excess pounds right now) are always in the 50-60 gram range.

        I bought a $25 digital kitchen scale, and log every item I eat. Like when making a big salad (something I’ve always done), I weigh every one of 10 or 12 ingredients (Romaine Lettuce, spinach, pickle :-), tomato, olives, raw almond slices, olive oil-based dressing, and any protein like a cup of chicken, beef or fish. It really isn’t hard to do once you get in the groove, and I find it a worthwhile process to really understand what I am eating every day. By bedtime, I have a complete chart for my day’s nutrition, and broken down by calories, fat, protein, and carbs.

        One advantage to this is really realizing which foods spike up the carbs, even if from natural sugars, like different kinds of fruits and things like yams. To maintain the carbs down in the 50-60 grams per day range (like I said…I am really trying to lose a few extra pounds), I am sticking almost exclusively to getting my carbs from vegetables. You’d be surprised how the carbs from 3 oz of green peppers, 3 cups of romaine, an oz of olives, etc etc, even though just 2 or 3 grams here an there…add up throughout the day.

        There is no question that before I started measuring and tracking my intake, even though I was eating “healthy”, I had no idea what the breakdown was, and often was eating more calories than needed to get the daily deficit I’m looking for.

        Ultimately, I won’t be weighing and tracking as religiously, but find that early in this journey (just finished my first week primal), it’s important in order to get a handle on the nutritional part of it.

        1. Love your post, i agree that there is a bit of carbs in green veggies such as green beans, brocoli etc. I am a carb addict and have been down the road of carb cycling or trying to many times, the only time i do find a difference and i love it is when i actually eliminate all grains and wheat from my diet, the spike in energy and good mood is amazing, you would think that it would keep me away from things like bread for example, but the moment i try a piece or i am at a party and have a bit of bread, or a muffin etc the binge continues on for two days at least and i got to start all over again! anyways long rant here ha

      4. I use some of the free trackers available online. My favorite is SparkPeople.com. You can get a complete nutritional breakdown of whatever you want to track (sodium, fat, carbs, calories, iron, fats, etc.). Another one is MyFitnessPal.com; freedieting.com, MyFatSecret.com.
        It’s interesting to track your intake for a month or so and see just what your diet may be lacking.

      5. IMO, tracking on a regular basis is minimally useful.

        I tracked for a year when I first went on insulin, to learn to dose to my food (the only real usefulness I found in tracking over a long time period).

        I found I could eat all the nonstarchy vegetables I wanted, all the fullfat dairy I wanted, a couple servings of fruit daily, and something starchy once or twice a week and come in under 100 g carb/day without messing with subtracting fiber or “net carbs” or such.

        IMO, having THAT info, how real eating over time translates into carb intake, is more useful than tracking regularly. Tracking is just for GETTING that information.

        Before insulin, I did < 50 g carb for over a decade, which still included all the veggies I wanted, but had to limit dairy somewhat (especially milk itself which is a bit carby), keep fruit down to a few servings per week rather than per day and almost never indulge in the starchy stuff.

        One has occasion to eat when there are no tracking tables handy, and rather than pull out your phone to hit the USDA database, it's handy just to know what food you eat!

        Generally, nonstarchy veggies have the most nutritional bang for the carbohydrate buck.

      6. You can check https://www.wellness.com/ for good resource on foods, their calories etc. Also in community you can find the goals, that can also help you with it. You set your goals, complete them, share them with other members of community, I got a lot fitter after using it.

        I would also recommend first to check with a BMI calculator and to check for a dietician – to see what fits and what doesnt for you. Limiting is never good, you can limit also vital resources for you body, that in long term may harm you.

        Take care in your journey!

    2. Excellent post. I can’t give enough credit to Mark Sisson and The Primal Blueprint. January 1 of this year I weighed 278. Yesterday, I weighed 238. That’s 40 pounds I have lost eating fresh fruits and vegetables (organic when possible) and all the meat I want. I prefer certified Humane, organic chicken, and beef, although I still consume a bit of bacon, sausage, and other pork. My cholesterol is better than text book, and my blood sugar as well. More importantly, I feel better than I have in the last decade, and there is significant more JOY in cooking. Thanks Mark ! Primal Blueprint is not a diet, it is way of life !!

    3. Yeah I’ve definitely noticed a lot of the ‘paleo’ bloggers back-tracking on the whole high-fat, low-carb idea. You’ve got Don Matesz repudiating the notion that Grok ate much fat, Stephan Guyenet saying carbs are healthier than fat, and even Richard Nikoley draining the fat off his meat and using a fancy “fat separator” in his latest post.

      Good to see Mark coming out all guns blazing to shoot them down with this well-researched, take-no-prisoners post that leaves no one in any doubt who the Primal Daddy really is.

      GROK ON!!

      1. Richard posted in the comments why he drained off the fat from that dish: “I wouldn’t have if I wasn’t replacing it with coconut fat. I just didn’t want [the] lamb fat to overpower the dish. Not certain it would have, just my preference.”

  2. I love that carbohydrate curve diagram. Tells me exactly what I need to know. Boom!

    It is so frustrating at times to live around people who carb.

    1. Haha i agree with the people who carb comment. I work at a salon where me and my boss both talk about PB to clients who are impressed with results then they like to try and argue why thats not healthy and what about whole grains. I just say well if your happy with how you look keep goin with that,find me in 20 years and we can compare then.:)

    2. So true. So many people I know that talk about losing their belly then eat a huge bowl of oatmeal for breakfast before going to their completely sedentary job.

      1. People who eat a big bowl of oatmeal are nice and thin. Oatmeal is high in soluble fiber, which control blood glucose, soluble fiber Beta glucan also boost the immune system and the digested fiber from the gut bacteria, butyrate feeds the colon cells. Beta glucan also helps remove cholesterol from the bile. Thousands of studies has left the irreputable benefit that FDA has allow for claim of preventing heart disease. The fat belly is from processed white flour which spike insulin like a bagel…processed food. !!!

  3. I encourage everyone to read Thomas Kuhn’s “Structure of Scientific Revolutions” which analyzes paradigm shifts in science. The process of converting a well-funded and well-established scientific elite will take a significant amount of time, but it is not impossible. Keep up the good work!

  4. The “pair of dimes shift” image made me laugh out loud. 🙂

    1. OK, took me a sec 🙂

      I don’t want to spoil it for others. It’ll come to you.

  5. “there is actually no requirement for any “essential dietary carbohydrates” in human nutrition”

    Vitamin C is a carbohydrate.

    1. “vitamin C, also called ascorbic acid , water-soluble, carbohydrate-like substance that is involved in certain metabolic processes of animals. Although most animals can synthesize vitamin C, it is necessary in the diet of some, including humans and other primates.”
      So not a carbohydrate…

    2. It uses the same receptors on our cells as glucose but it’s not a carb.

      By the way, eating a high-carb diet increases your requirement for vitamin C, which is why people on all-meat diets can get away with so much less C and never develop scurvy.

      1. Chemically it is a carbohydrate, but since it isn’t used as a source of metabolic energy, like starches or sugars, Mark’s general point is correct.

        You can’t generalise about macronutrients without braking eggs.

      2. I just read this bit from why we get fat. Interesting but awesome. Another reason not to eat fruit. Most of it is sugar.and vitamin c. Berries are awesome and bananas are for smoothies.

      1. Mountain goat liver contains between 10 and 30 THOUSAND milligrams of Vitamin C. I am surprised that I have not seen this discussed more frequently. Goat liver is by far the most vitamin C rich food in the entire world yet people keep talking apples and oranges…

    3. Vitamin C is ascorbic acid, which is a carbohydrate-LIKE compound. Thus, the statement still stands.

      Fun fact: the word vitamin came from the words vital amines from misconceptions in early research.

  6. I love this post. It’s so full of links! I am always pushing fat at my website and well, you know, you’re kind of an authority around here. It’s a pretty juicy post for reference.

    Question: what is your opinion of a super strict ketogenic diet? I have been trying for years to up my carb intake (the problem is even worse in recent months since my accident) but I just can’t seem to thrive with carbs. Even a little fruit or sweet potato will make me sleepy and well, all kinds of other things. I do eat something with carbs in it every few days but otherwise it’s zero carbs for me. And by the way, I do great with exercise and energy. I’m never tired and always ready to go. I did your WOW on Tuesday with no carbs as usual. Just wondering what you think in your vast experience. I don’t meet people like me too often, or well, ever…

    1. I am beginning to wonder if I have the same problem… After being primal/paleo for about nine months, I had a BIG slice of watermelon this morning. Instantly i felt shaky, irritable, needing to sit down. I also notice sweet potatoes make my joints hurt. I already subscribe to your blog so I’ll get your tips for “us weirdos” as you write them in the future. 🙂

      1. I’ve definitely noticed a new sensitivity to grains or sweets since going primal. It makes sense if you’ve stopped riding the insulin roller coaster known as the “Standard American Diet”.

      2. Pickle–

        Are you eating the sweet potatoes with the skins on? For some people, the skins can cause joint pain.

        Speaking of joint pain–mine has gone down considerably since I started PBL 9 months ago and continues to improve. I just noticed the other day, when someone pointed it out to me, that I can do deep knee bends without my joints popping at all. I’m 39 and my joints have popped when climbing steps or squatting down for as long as I can remember. I didn’t even notice they no longer do this because I’ve always taken it for granted that everyone’s joints, including my own, pop!

        1. My joints have cracked ever since I can remember(I’m 20). Do you know if the cause is solely based on diet? I’m of an athletic frame, and quite muscular (compared to non-athletic females). I am a vegetarian, and I do eat a fair amount of grains. I’m tall, and have just attributed the creaking to my height..

          TLDR; I’d like to hear your experience with creaky joints!

    2. I started restricting carbohydrates at 465lbs and a growing cornucopia of health problems. The weight gain I went through to reach 465 was absolutely frightening. On Mark’s chart it’s labeled “Insidious Weight Gain”, and it truly is just that. My numbers kept climbing, despite following the dietary advice of my Dr’s and nutritionist.

      Quite literally, carbs were killing me…and nobody knew what to tell me…Except that I must not be following the advice of my health professionals (this is how they accuse you of “cheating”). I was scheduled for roux en y gastric bypass in the hope that removing an otherwise healthy part of my stomach would fix whatever my problem was (yes, they never could explain what was wrong with me other than insinuating (or insisting) that I had an eating disorder, was lying to them about my food intake).

      The trouble with the carb model is not that it’s wrong, it’s that we insist it’s right even in the face of individuals that clearly experience detrimental health when following a diet based on it. We’d rather remove someone’s stomach than suggest reducing carbs. Even experimentally.

      Fortunately for me, before going through with surgery, I discovered that low carbohydrate worked for me. I had to do this on my own and it meant no longer working with my nutritionist.

      I’m down 120lbs now, and I’m acutely aware that I am very sensitive to carbohydrate. More so than most. If I exceed a very small range of carbohydrate intake, my weight loss stalls, I gain water weight, I start getting headaches, energy evaporates, rosacea flares up, etc…

      What I’m getting at is this: I’d say that it is entirely possible you have a carb sensitivity. If it walks like a duck, talks like a duck, and tastes like a duck…it’s probably a duck.


      1. Wow, that is amazing! It’s great that you have achieved all this weight loss and avoided gastric bypass surgery! You’re story is an inspiration and hope to many others in the same situation. Congratulations on your success with low carb!

      2. Michael, I’m in the same boat and always have been. Fortunately I have stuck to an Atkins styled diet since the early seventies or I would be really over weight and tired. The one time I did Ornish, 1999 keeping my fats below 9% I gained forty pounds in four months and sent my triglycerides and cholesterol well into danger zones. I wan’t over eating and was doing over four thousand steps a day. I am happy on zero carbs a day but do try to get about 2 cups low cal coloured veg a day (celery, Chinese broccoli and coloured bell peppers).

        I have lost 30lbs and have 20-30 to go. I am hoping that my body will weight itself out on this primal plan and any excess body and internal organ fat will balance itself to healthy proportions,
        My hours of sleep needs have dropped below 7 hours (Never really had any sleep probe) and my eczema is vastly improved, especially after I gave up my litre of cream per week in tea, coffee and coco drinks and given up all cheats (no desires any more for chocolate and ice cream.

        I understand that the body does balance itself out over time on this diet style.

  7. Gary Taubes posted his cholesterol numbers yesterday. I was just curious if you plan on posting yours as well.

  8. Thanks for this. I’m always trying to encourage the people I care about to think outside the box and get healthy. This might be the missing piece of the pitch. It’s interesting because I’ve been working on a blog post along similar lines, though not so detailed. There was also an article about a month ago on a cyclist who had gone paleo and no longer really needed to carb-load either on or off the trail.

  9. Do you have a link to any of the studies you mentioned? I am curious to read their results.

  10. There will be endless debate about how much fat paleo humans ate. The fact is that they were always going for the fat in any animal they killed. I.e., their bodies wanted fat. Having gotten of sugar and grains, I listen when my body asks for something. (Of course, my body might see an ad for a fast food triple cheeseburger with a perfect looking bun, cheese, tomato and lettuce, and tell me it wants one. I have to interpret that to mean some grass fed beef with pastured cheese melted on it and a salad.)

  11. I always get into the argument with my parents regarding “the brain needing carbs and glucose” to run effectively. I could never really articulate why that well.

    I will be sure to forward this link to them.

    I can personally attest to low-carb work outs. There was a two week period where I worked out fasted and my diet consisted of <50 carbs a day (mostly from broccoli or berries).

    I wish I had a popular outlet to share this info with, but I'll have to take it one person by one!

    1. One word response(if I am remembering correctly): gluconeogenesis

  12. It always annoys me whenever my friends say “Oh, so you’re doing a low-carb diet”. No! I’m eating normally, you’re doing a high-carb diet! I don’t understand how otherwise smart people refuse to look at the clear evidence of chemistry, biology, and history. Great post.

      1. Couldn’t have said it better myself. The only time I say “low carb” is when I go ketogenic. Otherwise, it’s just “normal” carbs while everyone else is doing ridiculously high carb diet.

      2. Please, stop the rhetoric already. I really don’t see an agreed upon body of facts showing that “Glucose is not the preferred fuel of muscle cells…. Fat is”. The studies contradict. There is a lot we don’t know about the physiology. If anything, for modern peoples, the things I really know suggest to me the superiority of glucose:

        1. Most of the world eats and has eaten a high carb diet without “insidious weight gain”. Obesity is something new to modern western and westernizing peoples. Carbs are older than civilization.

        2. Everyone reading this’ ancestors for many generations have been eating a high carb diet. Epigenetic effects persist over multiple generations. You say yourself that we all grew up adapted to be sugar (glucose) burners. Is it not possible that we really can’t “reprogram” our genes completely after we are fully grown? I don’t think you can prove that we can. There is too much we don’t know and I think you commit the naturalistic fallacy.

        3. As argued in “10,000 Year Explosion”, a lot of genetic change can happen in a small period. It is plausible that most modern people are descended from those who could tolerate grains/carbs better than those who couldn’t.

        4. My own personal experience eating low carb was far from entirely positive. I was skinny and I lost weight in a bad way. My experience was consistent with those claiming that low carb/high fat is associated with stress. I believe my body was in a highly catabolic state. My stress related conditions got worse. I’ve had huge improvements and increases in energy by eating more carbs and cutting out other things like fructose and omega-6.

        5. Certainly it is possible that “I wasn’t doing it right” (I admit that i probably wasn’t), but doesn’t that suggest that there are major pitfalls for a modern person trying to emulate lifeways long dead? Doesn’t that suggest an element of impracticality to the whole low carb game?

        6. There is indeed a lifestyle problem of having to prepare all your own foods and eating very different everyone else around. For me it really wasn’t as practical as eating more rice and spaghetti.

        I haven’t read your blog for awhile and this post is disappointing because you are a good writer that appears to have solid analysis and good advice on many things. It seems like you should know better and I think your advice will incite many to hurt themselves. I reiterate that the fallacy of the “high fat” camp is the naturalistic one. Not to mention that I’m skeptical that we know very much about what prehistoric peoples ate.

        1. BTW – this is only scratching the surface. Much more could be said on this.

        2. 1. I agree. It’s not the carbs, or at least not the carbs alone. It’s what Kurt Harris calls the neolithic agents of disease, excess: wheat, fructose, and linoleic acid that cause most of the problems with regard to diabesity.

          2. Programming your genes is nothing more than bad terminology. I have some genes which predispose me to celiac disease, but I don’t have celiac. I don’t eat gluten containing grains so those genes would not be expressed. That’s my understand of “reporgramming your genes”

          3. No argument that fast genetic change is possible, but in my personal experience I have found that most people have the genes to handle large amounts of grains without issue.

          4. Primal isn’t low carb. Most people don’t like ketosis and they eat enough carbs to stay out of it. 150 carbs a day is a moderate carb diet and plenty to eat lots of nutritious fruits and veggies. It only restricts grains.

          5. Sounds like you were not eating enough carbohydrate to stay out of ketosis and this was causing problems stress. 150 grams is a substantial amount of carb.

          6. It’s not that difficult. Meat and veggies and occasional fruit. It just takes experience and planning.

    1. When people ask me why I look so good and how I lost so much weight, I’ve been saying “I eat real food now, and not the refined, processed stuff.” The same people who would say ‘oh, low carb diet, not safe, kooky, etc.’ say, wow, that makes a lot of sense!

      1. Yeah, that’s what I’ve decided I’d say because they are more receptive to it than the phrases that have been stigmatized.

        If they try it, in the long run, they’ll reduce carbs automatically, because processed foods are typically high in carbs.

      2. Where are your evidenced based articles to support all of your theories?? I thought excess calories = weight gain…not carbohydrates. Isn’t it true that fat provides 9kcal/g and carbohydrate provide 4kcal/g? Therefore, that would mean more fat= more calories..correct?? Our brains exclusively use carbohydrates for fuel…if we do not have carbs we rely on ketone bodies..which therefore our bodies go into ketoacidosis… Also, when we are in the anaerobic state…we only use carbohydrates as a source…such as a sprint or quick movements…you are saying if i have a low carb diet this will be more successful?? I do not understand. here is an article you can learn from.


        1. As a RD, you should know better. Re-read Stryer, or Guyton Biochem books. You are still responsible for the info….Specifically pg. 770 in Stryer…integrated fuel metabolism

          Calories in vs. Calories out? The neurohormonal regulation of appetite destroys that idea. Satiety control in the body is a system-based entity…not linear. Humans are not “physics-beaker-experiments” aligned with the First Law of Thermodynamics. We loose heat/energy to the environment, we use energy to make energy, energy production uses enzymes…etc

          The brain can use ketone bodies for fuel very nicely. It does NOT exclusively use carbs for fuel. During starvation (in between meals, sleeping every night) and ketosis, kb replace glucose for the brain. 70% of the brain function can convert to kb use.

          And the heart prefers to use kb for its energy needs. It prefers to use acetoacetate to glucose. Heart, lungs, muscle, tissues prefer preferentially to use kb for energy needs. They run better on kb than glucose.
          Here’s an article YOU can learn from:

          Using kb for fuel, does not put us into ketoacidosis. This is a pathological state occurring in UNCONTROLLED ketosis. Ketosis occurs every night when you sleep. It’s part of fat-based energy metabolism. In ketoacidosis, the body accumulates keto acids that the pH of the blood is substantially decreased. Those are two vastly different metabolic states.

          Ketone bodies are relevant to neurological diseases such as Alzheimer’s and Parkinson’s disease, and the heart and brain operate 25% more efficiently using ketones as a source of energy. Research has also shown ketones play a role in reducing epileptic seizures with the high-fat, near-zero carbohydrate Ketogenic Diet.

          1. I’m a holistic dietitian and I’m sad that other dietitians are still lacking in knowledge. Ketones are an adaptive response not “preceded”. Glucose is the most “efficient” or easy fuel. Ketones have healing benefits but the body runs on glycogen. You will notice that your blood sugar remains stable while in ketosis. You can gain weight on a ketogenic diet if fat intake exceeds energy needs. High fiber diets also show healing benefits for neurological issues mainly because of the production of short chain fatty acids from gut microbes. Yes, higher butyrate levels is protective. Our obesity is from excessive intake and inflammation. You can live a very healthy life on a plant based diet with fruit, vegetables, and starchy veggies. So perhaps study of the microbiome should be your next quest.

        2. ‘registered dietician’: that tells me all i need to know.

        3. RD, MD – both suffer corporatised brain wash to conventional thinking and their boxes are closed or their would not be able to work within their professions. If the modern medical industry had any credibility we would live in a skinny world (Western Civilisation). Case closed.

          Allopathy has failed miserably and that is why so many are now choosing to think outside those closed boxes of failed logic. Think Semmelweis, Copernicus, Galileo.

          Remember the silliness of Ancel Keys?

      1. my ditto went in the wrong spot.ugh It was intended for Tim’s reframing statement.

  13. The depressing part of this is it’s so hard to find ‘full fat’ foods in the supermarket or anywhere. I needed buttermilk for a recipe a while back (sorry – I know I should be avoiding dairy) but it was IMPOSSIBLE to find a full fat version. I looked everywhere.

    At my workplace, our cafeteria only serves ‘low fat’ chicken salad and only ‘low fat’ salad dressings, etc.

    It’s incredibly frustrating.

    1. You don’t have to avoid dairy if you’re not allergic to it. Just go for fermented over regular milk, and try to get grass-fed dairy if you can. It’s a good source of saturated fat in a culture that worships lean meat.

      By the way, buttermilk is supposed to be low-fat, if it’s real buttermilk. It comes from fermenting milk and then churning butter from it. That process produces skim milk that has been fermented with lactic acid bacteria.

      You can make your own full-fat buttermilk–Cultures for Health sells the culture. (They’re online.) But as buttermilk is fermented, the lack of fat in the real stuff doesn’t matter. The lactose is mostly gone too. You drink it more for the good germs than anything else.

      1. I would like to find out what they are doing with all that dairy fat. Call me paranoid, but if I were a company, I wouldn’t spend lots of time and money removing fat if I didn’t have a way to sell it, so I wonder if the low fat craze is just a way to have leftover fat to sell.

        1. Actually, the low fat thing was about selling dairy without fat. When they make butter and cream, the good and expensive stuff, they have a lot of skimmed milk left over. The SKIMMED MILK is what they are trying to get rid of.

          1. But they sell it at whole milk prices, and the cream and butter at much higher prices. Very profitable.

        2. I watched a very interesting video (wish I had the link) where an independent doctor investigated the panel of doctors who set the standards for healthy cholesterol levels. His research proved that these 10 or so doctors were either getting paid directly by pharma companies or owned pharma companies themselves and they set the precedent that fat is bad, cholesterol over 230 is bad (when actually there is no correlation between cholesterol and heart disease unless your levels are 320+).

          Anyways if you look into Lipitor it is one of the highest grossing pharma products of all time. That’s a lot of incentive for these funded doctors to sway the decision to promote fat is bad and high cholesterol is bad.

    2. You’re right!
      My husband and I have a really hard time finding FULL FAT dairy products…everything on the shelves is now fat free…frustrating.

      About 2 years ago the selection was still bigger…they now got rid of all the fat.
      That goes to show that the CW movement is pushing harder than ever into the wrong direction…we don’t even get a choice anymore.

      Thankfully there is a Co-op 120 miles away that carries everything full fat …we drive there once a month and stock up. Hell of a drive though.

    3. Buttermilk is supposed to be skim milk. If you can find Bulgarian buttermilk, though, that’s made with whole milk. Or add cream to regular buttermilk.

      I’ve never had trouble finding full-fat versions of any other dairy products.

    4. On the contrary, dairy is essential on a keto diet. Pass the cheese please.

  14. great post, because this is about so much more than just weight loss.

    1. To the extent that even slender people should be worrying about this because they’re not exactly healthy either.

      There are slender people getting high blood pressure, demented cholesterol levels, metabolic syndrome and type 2 diabetes. But because they’re not fat they dismiss it all as “hereditary.” Like as not their doctors are saying the same thing.

      Fat people are lucky. We got an early warning signal. But as long as we make good health about fat-bashing, a lot of people will continue getting sick who think they are the picture of health because they are at a normal weight.

      1. Yes! I was really startled last week when my friend, who has a history of life-threatening anorexia, now recovered but still very slim, told me she’d been diagnosed as pre-diabetic! She also has several auto-immune conditions. I gave her my hard copy of PB.

        I’m guessing it’s due to a lifetime of fat-phobia?

      2. My blood sugar problems are hereditary. It is the *results* that are not. I could eat cookies all day long and end up insulin-dependent in a few years, or eat steak and be fine.

        The people around me seem to think this is a tough choice. I think I’ll go for the needles when hell freezes over. 😀

      3. Agreed–I work in health care and see skinny type 2 diabetics almost as frequently as those who are overweight. And most of the ones with “normal” BMIs are the ones on dialysis. Of course they are not truly thin, they are, to coin one of Marks’ phrases, “skinny-fat.”

  15. When people say glucose is the preferred fuel for the human body, they are misconstruing the basic biological reality that the body burns glucose preferentially. They’re interpreting that reality as the body saying “Ooh, I would really like a Twinkie right now, Twinkies are my FAVORITE!” when actually the body is saying, “HOLY S?!T! INCOMING! GET IT OUTTA THE BLOODSTREAM NOW!!!” *sirens going off* *pancreatic panic* etc.

    I’ve begun telling people, “Alcohol is an even more preferred fuel than glucose. So when are you switching to a beertarian diet?”

    Most people understand that alcohol gets burned first, when they understand that at all, because alcohol is toxic. The body’s found a novel way to defend itself from a poison, by turning that poison into a fuel.

    Well, it’s done the same with sugar. That’s where people’s logic processes start breaking down. They can’t quite get their brains around this idea. Shame, too.

    1. Great post! I cant understand why anyone would deny what Mark is saying here. Our anatomy/physiology tell the truth about what we need to eat. When people stop trying to eat based on their morals and beliefs and start making their body work for them this will be a much healthier and happier world!

    2. Thank you for this comment. This puts the “body prefers glucose” statement that I’ve often heard in perspective.

    3. When I told my mother that I cut out all (xept fruit) processed sugar, grains, legumes and tubers out of my diet she went into panic mode, then said :” Omg, you’ll get under-sugar and die!” Like sugar was some kind of staple.

      I rofl’d.

    4. ‘The body prefers glucose’

      Yeah, if our bodies prefer glucose so much then why is it that when there is surplus glucose, we change it into fat to store it.

      That’s not a spare tire of sugar around your middle people – it’s fat!

    5. “Pancreatic panic” and “turning that poison into a fuel” are like political sound bites and not even correct.

      Rice has been the staple of Asians for thousands of years. They didn’t suffer insulin resistance and the likes until the recent adoption of industrial foods.

      As Mark pointed out, you need a lot more carb than 150 g/day if you engage in high intensity acitivities overy long durations repeatedly. I recall he suggested 100 g for each hour of exertion. Glucose is a high grade fuel when you need a lot of power for a sprint. Fat burns much more slowly, but there is a lot of it for a long jog. Different fuels for different needs.

      It is true that most people don’t need much, if any, high grade fuel. The chronic consumption of carb, in the absence of glycolitic activities that demand it, causes the body indeed to prefer metabolizing glucose even for low intensity activities. And that is the problem, not the consumption of carb per se.

      By the way, it is not true that the “basic biological reality” is “that the body burns glucose preferentially.” In well trained athletes and even couch potatoes with lucky genes, their muscles actually burn fat preferentially until the demand for power exceeds a certain level. Raising this level of fat burning is a key training objective of endurance athletes who also get at least 60% of their energy from carb to maintain high performance. Illogical? Nope, not if you really understand what is going on scientifically.

      Biochemistry is far more involved, and human metabolism far more complex than your simple logic.

      What Mark has said is very good and sound scientifically. But some of the enthusiasts here are annoying with their lack of real knowledge and their self-righteousness

      1. Thank you. This may be the best post I’ve seen on the internet in many years. While I’m not a dietitian by any stretch of the word I do know bull$#!! over 50% of the time when I see it. Mark has some studies backing his statements (which appeals to me) but I haven’t seen the full studies so I don’t trust them. I do however trust my body to crave what it needs (now that’s primal…) and MY body craves MEAT and vegetables and fruit. I don’t necessarily agree with the whole low-carb no-carb fad but I eat what my body craves and it pretty much craves primal. Never been a sugar man myself sans energy drinks which sated my cravings for caffeine for a long time. That is pretty much all I have given up in my quest for a primal diet and I think my body is happy here which means I will stay here until my body doesn’t seem happy with it anymore.

        1. I will have to say though one could get much the same results by removing just the processed foods and sugar from their diet. I got rid of 30lbs in 3mo doing that (almost straight from obese to my ideal weight.)

        2. i agree! Im good at picking out good nutrition sources and this article kept me intrigued! Ive been studying nutrition for abot 10yrs seriously! Im a kinesiology student and fitness coach so Im always trying to gain an edge with health/body comp.

      2. Not true,

        Insulin resistance is a huge problem in East-Asian, white rice eating, countries.

  16. Great post! As always. Going Paleo has made gigantic changes in my life! Thank you for what you do!

  17. Whenever people warn me that I’m doing myself in by restricting carbs because “carbs are the body’s preferred source of fuel,” I tell them, well, that all depends on how you define “preferred.” Too much blood sugar is toxic, so if you define “preferred” as “my body burns sugar first because it prefers not to die,” then yes, fine. But if you define it as “my body prefers a steady source of energy,” then fat wins hands-down.

    Some people have an “aha” moment…most still don’t. Sigh.

  18. Oh believe me – this is soooo true. We were in Hawaii 2 weeks ago for our wedding. Of course we had a cake. A beautiful orange chiffon with lemon curd and butter cream icing. I was nearly 90% primal before the wedding. I was humming and hawing on eating any of it because I have glutin intolerance as well. But because the baker had made a cake for nearly 25 people (we had requested a small cake for less than 10 people) we had sooo much left over and we hated to waste it. I finally broke down and had some. The cake was fantastic. BUT. I quickly felt the sugar addiction returning and the weight gain was nearly immediate. The only bad thing I ate during that week was the cake. I probably gained 5-8 lbs since then and the sugar craving is incredibly difficult to beat. I regret making the decision to eat that cake. Sometimes it’s better to just leave well enough alone.

    1. I totally understand where you’re coming from with the cake kicking off your sugar addiction. I did exactly the same thing on my birthday a couple of weeks ago because my Mum made me a cake and it seemed churlish not to eat a little bit. Well a week later I was still gaining weight and the only way I found to turn off the sugar cravings was to do a 36 hour fast – worked a treat, I’m now back on the weight-loss curve and no more cravings. Good luck.

    2. if you can go three days with zero effective carbs you can pretty much kick the physiological craving. The psychological cravings keep coming back, I’m beating them back with a square of dark chocolate (85%)

  19. This is one of those posts that is absolutely true, but won’t accomplish anything. Those that are dead set on the carbs = life hypothesis have clung to it in the face of all the facts of dietary research over the past century. Logic won’t convince them.

    1. Cheer up! This will indeed accomplish something, because not *everyone* is dead-set on *anything*.

      There’s always someone balanced on the fence who will come down on the right side, if given a tug.

      And there are always others who’ll move closer to the fence and look at the other side.

  20. Thank you! This is just in time for me, Mark!

    Although I love my athletic friends I am just so tired of their “carb-up or your muscles will get eaten away” rhetoric. I’m just as strong as they are, and they’ve got years in the gym under their belts. (I’ve got 1 year at the end of this month.)

    They’ve got good genetics…and hearing them say this stuff over and over again was really wracking me. I agree with an above poster who said a predisposition to gain weight is a GIFT! I may not look as “good” as them yet…but I’m strong with great endurance. I eat a healthier PRIMAL diet, and as the weight comes off I hope they’ll be more open to PB…or at least spare me their soliloquies!

    I feel great. Run far and fast. Lift heavy. Take care of a house, 2 kids and a huge garden. I feel like my energy is limitless and even they remark on it!!

    Again–THANK YOU!

  21. Great post, and timely too. The fat vs. carbohydrate debate seems to have really picked up recently.

    If my understanding is correct, glucose is the “preferred” fuel only because elevated blood glucose is toxic. So the body has to burn it first to get rid of it.

    So it’s preferred in the sense that it’s used first, but certainly not in the sense that it is superior.

    1. Yeah I’ve definitely noticed a lot of the ‘paleo’ bloggers back-tracking on the whole high-fat, low-carb idea. You’ve got Don Matesz repudiating the notion that Grok ate much fat, Stephan Guyenet saying carbs are healthier than fat, and even Richard Nikoley draining the fat off his meat and using a fancy “fat separator” in his latest post.

      Good to see Mark coming out all guns blazing to shoot them down with this well-researched, take-no-prisoners post that leaves no one in any doubt who the Primal Daddy really is.

      GROK ON!

    2. The body doesn’t have to burn glucose to get rid of it. It can also store it as glycogen, or as fat if glycogen stores are full.

      1. It would be more accurate to say that glucose-burning shuts down fat-burning while glucose is pouring in.

  22. Dana, best quote of the week, “when are you going beeratarian” great point and background about sugar being poison.

  23. Brilliant post. Now how do I get everyone I know (and most of the people I don’t!) to read it?!!

  24. As Mark said in the post, once you eliminate all the crap (especially grains) the result is simply low-carb. I don’t really feel like I go out of my way to keep carbs down – when I’m eating plenty of fats and meat with some veggies, it just kind of happens.

  25. Great post! I’m glad to see you are sticking with your carb chart and not changing it. There is getting to be some fat bashing in the paleo sphere, I’m happy to see the Primal Blueprint stay the course.

  26. I tried the PB and loved it, until I realized that the lack of grain intake had driven my already faulty neurochemistry way way way out of whack. I enjoy being able to hyperfocus at will, but not being able to make it stop was really quite detrimental at work. Any advice for those of us who would like to be primal again, but need extra help with serotonin production?

    1. Try “The Mood Cure”, or the similar book “The Diet Cure” both by Julia Ross. Details how to stimulate more normal neurotransmitter production by supplementation of precursor nutrients.

  27. whats more important for muscle growth , stimulus to the muscle ,total calories or # of grams of carbs in the diet.

  28. I can attest to the insidious weight gain, and while there has been much about my diet that was very good, I decided to get back on track and used this carb chart to meal plan for my wife and myself. For 3 days, I don’t really watch what I eat; for 4 days, I ensure that I eat <50 g. carb. per day; for 5 days, I work out (usually short runs). So far the results have been very good for someone who's never been a "dieter": 12 pounds down in 5 weeks, and my wife has remarked often about my energy. Lots of other useful info from this site that generally fits with my overall nutritional belief system, so the reinforcement is good.

  29. As my success is so apparent I’ve been getting questions about how I did it. I loan or get folks to buy the book but I can tell it won’t be followed or it will be tweaked 50 ways before it’s tried.

    They are following their “Dr’s orders” after all so you are right, this MUST change. I’ll be attending your talk next week in NYC, I hope you didn’t give it all away here.

  30. It boggles my mind that so many Paleo types will not admit that starch is a preferable fuel for athletics compared to fat … performing on fat is sheer agony compared to using starch as fuel.

    In the article Mark says “unless you’re an athlete …” That’s a pretty big “unless.”

    Okay if you’re a soccer mom I can see how you can get by on low carb, and if you are obese then you definitely need low carb, but if you are a normal healthy guy, and you are not an athlete, imo you have to seriously reconsider how you are living your life … why would you NOT be an athlete?

    1. True, but it is quite hard to run out of muscle glycogen. It takes about an hour of running at a moderate pace before you hit the “low carbohydrate wall”.

      So if you regularly run for more than an hour, you need to eat more carbohydrate. However, if you do HIT and resistance exercise, you don’t.

      1. I don’t think this guy is fueling his running with carbohydrates every hour.

    2. It has nothing to do with “preferable”.

      Fat oxidation can go on forever (relative to a day’s exercise), as we’ve got plenty of fat…but we can only oxidize it so quickly.

      Glycogen can be oxidized as fast as we can take in oxygen…but we can only store so much of it.

      Endurance exercise is all about optimizing both of them. The high-carb brigade only pays attention to glycogen, ignoring the facts that low-carb eating, exercise, and fasting increase the ability to oxidize fat, which determines baseline performance.

      As Jonas Colting says, “Train low, race high.” Leangains is low-carb on rest days and high-carb on workout days. Maximize your ability to oxidize fat by training on it, and load up on carbs when you need that maximum performance.


    3. So what proportion of the general public are athletes, assuming that athletes need high carbs. Maybe they are just out of sync athletes. Besides, look at the early death rates of long distant marathon runners and other intensive athletes.

      I have always beed a pudgy fellow with poor tone. Going raw primal I found that I lost my weight and now my body is muscular and taut and I don’t exercise any more than I did when I was overweight and flabby. Most of my fit thin friends are the same. Mayn’t be a scientific study but my health on primal is certainly better than when I followed the pyramid and rarely ate sugar or processed junk foods. I just do not process carbs well, just as most people in our modern western world seem to fail at as well.

  31. Reposted the link to my facebook page, asking people to read! This is a great article. I went primal on 1/1/2010. Immediately dropped from 185 to 165 lbs. Never felt better, ever! Age 40. Thanks Mark! I am spreading the word to everyone, all the time. Thanks again!

    1. Wish you’d tell me…I just went from Keto to Carnivore this year….and I can already tell I’m gonna be mainly Carnivore for the rest of my life…already lost almost 10kg of fat (and a touch of water lol) … and the strength is amazing…doubled my reps in the gym in one week!

  32. I have to say that after doing PB for about 3-4 months, I felt like hell. I was tired all the time, gained weight, and was just generally sucking at life. But I wonder if it has something to do with this:

    There is a downside, however: you can’t train long and hard day-in and day-out in the fat paradigm.

    Does the carb curve change for those who do things like CrossFit? Where is the boundary for actually needing to increase your carbs? I increased mine from about 75 a day to closer to 120 a day on average and I feel much better, but I have to wonder what is ideal for different activity levels. Can we get some guidelines on that maybe?

    1. Athletes can absolutely perform well on very few carbs.

      Most people don’t realize that a low-carb diet automatically flushes salts from the body via the kidney. Add to that the heavy sweating experienced with hard sustained workouts and you have a recipe for dehydration and electrolyte imbalance.

      I know a lot of athletes who are concerned about looking good all the time and cut all the salt they possibly can from their diets because they are afraid to retain water weight and look “puffy”, but low-carb is inherently low-salt, and salt needs to be supplemented on low-carb, especially for active people.

      Electrolyte imbalance = “sucking at life”. Not having enough salt in the body feels awful!

      As with any diet, people need to do some research on how to low-carb safely, effectively, and successfully. My favorite low-carb publication thus far is “The Art and Science of Low Carbohydrate Living” by Dr. Stephen D. Phinney and Jeff Volek. This book blows the myths, lies, and misunderstandings about low-carb right out of the water.

    1. I quit logging my food during that time since it isn’t considered necessary, but I did log here and there, just to check my ratios. Here is what I had one day: 1951 calories, 150g fat (68%), 71g carbs (14%), and 86g protein (17%).

  33. I just did a 1.5 day fast and posted a pic of what I ate when it was time to eat again..on Marks FaceBook page…
    go see
    GROK ON>>>

  34. I am a work in progress as I slowly adapt the Primal lifestyle. “All in” didn’t work for me so I am trying a more gradual approach. I am currently on day 66 of a planned 100 day no added sugar eating plan. I still trend toward the higher end of acceptable carb intake, mostly sweet potato and fruit, but I don’t crave the sugary crap I used to eat. I am finding it hard to replace carbs with fat, and instead feel like my protein intake is trending up a bit too much. This is mostly in the form of beef, salmon, and some eggs. I went overboard with nuts awhile back, so I tend to stay away from those. The lack of variety is getting a tad boring.

    So, my question to you is…

    What are the easiest ways to add fat without also adding too much protein?

    Right now I enjoy coconut oil and real grass fed butter, but I am looking for other suggestions.

    1. Easiest way to get fat without protein is to buy just the fat.
      I have grassfed/finished kidney fat in my freezer.
      Just break a piece off and fry it in a pan, add salt and enjoy.

  35. I remember watching nutrition films in grade school (early 80’s) that told us that fat was good. I even remember making a point of eating the fat on steaks and pork chops because that’s what they told us to do in school. Does anyone else have similar memories? I wonder what happened to that line of thinking. You would think the beef and pork lobbyists would be all over that.

  36. Been following the PB for a little over a year now and it works.

    Even with my 1 Quart of raw milk a day!
    Very impressive 🙂

  37. Mark, I really love the Primal lifestyle–though with respect to diet in particular, I tend to feel better on the Jaminets’ Perfect Health Diet. My question concerns furious carb cravings when thinking hard. I’m a techno-geek by profession (something that while stressful at times, I truly enjoy), and when the grey matter is working madly away, I am invariably in the throes of carb cravings that I can honestly say I would otherwise NEVER get. (I am one of the lucky few who have a near-negligible sweet tooth.)

    What gives, besides the brain’s presumably higher consumption of glucose? And more importantly, what can be done about it? As much as I’ve tried, Primal munching (unsweetened coconut chips, >85% dark chocolate, meat, what have you) just doesn’t cut it. A Primal solution would be much appreciated!

    1. Hi Michelle,

      I have similar experiences to you. My profession also requires bursts of intense thinking, focusing, calculating by hand/mind and extended periods of FULL concentration and when I’m having one of those days/weeks I also find that I crave carbs. Not specifically sugary junk things, but I end up going for things like rice and potatoes way more than I normally would. Actually this week has been mentally very, very intense and my carb intake has gone up quite a bit with minimal impact on weight or intestines like I normally would have. Maybe my used it all up (similar to how an athlete would use it up).

      Like you I also find that primal munching doesn’t cut it so this week it was quite a bit of soaked and sprouted chick peas, white rice and potatoes. Not truly primal and not normal fare for me, but a good compromise, I hope. When I can’t be fully primal I hope that Weston A Price style eating is a happy intermediate.

  38. Mark,

    I thoroughly enjoyed this post as it contradicts nearly everything my nutrition professor lectured about in college last semester. I do have one question though that is foggy to me. Generally, health advice often states that when the body does receive enough carbohydrates for energy, it turns to the protein in muscles first, as opposed to fat. Why is this used as an answer, and is there any evidence to support this statement?


    1. It may contradict what your prof was emphasizing, but if the course taught any science, you should still have gotten this same info. That was always my experience, that it was there all along, just ignored.

      Fat is what your body will burn after running out of glucose, such as in longer moderate exercise.

    2. Andrew, your prof is mostly right. If you live in the Carb Paradigm ,where all your energy systems crave glucose and can’t access or easily burn fat, then, yes, that’s exactly what happens: you run out of glucose and the body turns to protein (usually in muscle) to make more glucose. It’s why fasting is not as effective for sugar-burners.

      In the Fat Paradigm, once you have become fat adapted (up-regulated enzyme system to increase beta oxidation of fats and down-regulated glucose oxidation mechanisms), your body will look to fat stores for energy instead of muscle. No problem.

      1. The main reason is that fatty acids can’t cross the blood-brain barrier, so the body needs to either make glucose from protein to feed the brain, or start making ketone bodies.

        Using ketones is rather inefficient, which is why this pathway only happens after a few days of starvation (or during hypoglycemic shock when a diabetic injects too much insulin).

        1. “…only happens after a few days of starvation (or during hypoglycemic shock when a diabetic injects too much insulin)…”

          …or when I eat my normal diet.

          Also, please Google “Fatty Acid Transport Through the Blood?Brain Barrier”. Some of the shorter-chain fatty acids are transported and metabolized.

  39. Great article! Thanks! Also, just wanted to say thanks for writing the book – I just finished it and it was great! I learned so much! Thanks!!!

  40. Mark, you’re on FIRE! Love it!

    I know youse a busy man, but I have a question I’m not seeing an answer to yet, and maybe some kindly comment readers will know as well.

    So those “lucky” ones who don’t get overweight eating the SAD, are they also susceptible to the other health ramifications or are they somehow immune to those to? Is it the body’s response to the SAD that begins the cascade of other health problems and if you don’t have that response, then you’re in the clear?

    Just curious since many of my friends are these “lucky” ones and can see no reason to entertain a dietary regimen change. *sigh*

    1. Yes, skinny people can still develop all the “diseases of civilization,” including heart disease and diabetes. So being naturally skinny doesn’t automatically mean they’re healthy.

      1. It’s so frustrating when skinny folk think they’re immune. As though all this diet is about is weight loss…ugh.

  41. I think I love you.

    … But on a more serious note, this was incredibly informative and further solidifies my choosing this lifestyle.
    Thanks so much for everything that you do, Mark!

  42. Thanks for this timely posting, Mark. Yeah, the debate over on Don’s blog (since removed — evidently a little back-peddling on Don’s side) did confuse me about whether I should be cutting down on the animal fat and upping the carbohydrates. I’m glad to get your position on this. I’ll stick with my Primal BP shopping guide until I hear otherwise from you!

  43. Foraging wild foods is one of my hobbies and with the exception of the fall when the various nuts are available and a few wild tubers there are not many carbs out there for the picking. Depending on the season and where you forage there may be close to none.

    Occasionally I try and do a weekend where I only eat wild foods that I have collected one way or another. I always find myself falling back to the fish and game for a majority of my nutrition.

    I imagine that Grok was in the same position much of the time.


  44. Pro-carb bloggers however always refer to people in the far east who eat 500 grams of carbs a day (or something to that effect according to them). How do you explain that?

    1. They do eat rice, but they still eat fewer carbs than we do. And virtually no sugar or refined flour. I wish I could remember the source, but I read that the average Japanese man consumes 1800 calories per day, roughly 50-60% of that as carbs, which comes out to about 270g carbs per day. The average American, in comparison, eats 350-400g of carbs per day. Plus ten times the amount of soda!

    2. I think the China Study, when you look at the data and not the conclusions, shows that white rice comes out almost neutral, whereas gluten is absolutely shown to follow morbidity.

    3. As of March 2010, China passed up India as the diabetes capital of the world. Sounds like a good explanation to me.

      1. why does everybody thinks the whole China only eats rice? it’s not like they are high carb rice-based vegans.
        have you seen all the pork they eat?

        not to mention all the processed crap that, yeah, incredible, it reached their country!

        yes, rice (carbs) plays a main role in their diet but mix that with pork (fat) on an absolute daily basis, of course you’ll end up with all sorts of medical conditions.




  45. Great post. I just wish all the S.A.D folks and other slaves to the status quo would read this article and embrace it. I’m in my third year of college as a Fitness and Nutrition major and I am sooooooo sick of hearing the same old bull about glucose and carbs and the food pyramid. It’s just so frustrating and it gets in the way of my willingness to learn.

  46. Mark, I’ve always thought of you as the gentle soul among the best-known proponents of a primal/paleolithic lifestyle. But you showed us in this post that you have quite a bit of fight in you. Bravo! Keep it up. We need strong voices like yours.

  47. Im so glad Mark posted this. I know myself, I already feel amazing on a Primal Blueprint diet, but lately Ive been staying in keto, and I dont know if its mental but its like Primal x 10. I feel the difference, I literally feel like a beast in the gym in keto, and I manage to stay in keto even eating potatoes a couple of times a week. Although that is cause Im mostly carnivorous haha. Anyway, great to see Mark finally shed some light on this subject since many low carb gurus have different opinions on ketogenic diets.

  48. Thank you for this post! I can’t tell you how much grief I’ve gotten over the last 48 days. 48 days ago, I started eating Primal, cleaned up my diet (and my body!), and let go of my carb addiction. Since changing my eating style, I’ve lost weight (20 pounds!), started sleeping better/longer, and have had way more energy.

    When people ask me how I’ve done it and I describe a Primal diet, I’m amazed at the (occasionally angry) response. In the same conversation, someone will praise me for looking fit and then berate me for not eating a ‘well-rounded’ diet.

    I know I’m talking to Noah about the Flood here, but ever since I hard-core committed to eating Primally, I haven’t eaten so many vegetables in my life!

    Love this post. Thank you!

  49. This blog post really hits home to me. Maybe I’m so vain that I actually think this post is about me (laugh), but I’ve recently discovered the effectiveness of the carb refeed.

    I would never advocate a high carb diet and I definitely agree that fats are the ideal fuel for humans. Yes, we burn glucose more readily than fat, but we’ll also burn alcohol more readily than glucose. Do I hear anyone advocating a diet composed primarily of ethanol? I love my 60/30/10 fat/protein/carbs ratio, but when you get in the leaner body fat percentages, a 48 hour low-fat carb-up can really get the metabolic fires burning again.

    I don’t think carbs are evil – particularly starches. I think they’re great if you know how to time them, and you don’t make them a staple. A sweet potato every day would probably be a poor choice for your weight loss, but a pound of sweet potatoes once a week with half coming pre-workout and half coming post-workout could really help you break through those plateaus.

  50. You only got one thing wrong. Hard work every day is possible on a vlc diet, and I’ve been doing it for some time now.
    Weight lifting 3-4 days a week, sprinting and walking whenever the weather is nice enough for it. VLC works just fine for this, although I have noticed that lifting 3-4 days a week generally doesn’t give you a break from DOMS.

    1. @Alex, nice going. For high-intensity work, muscle glycogen is still the limiting factor. If you keep your HIIT stuff short and sweet, you can be VLC and still refill stores every two or three days without a lot of carbs. You just can’t go long and hard every day. And why would you want to? There’s no strength or fitness benefit to going hard every day.

    2. I’ve been doing low carb for probably a year now. I did keto for 8 weeks last year and worked out hard every day before I knew any better. Even on keto, I ran 17 miles a week and lifted 4 times a week. It was brutal.

      Since going Primal 3 months ago, I’m seeing far better results, and I started taking up sprinting. I typically take in around 80g of carbs a day and HIIT is no issue. Carb refeeds are something I’ve only recently incorporated in the past month. I honestly don’t feel working out is any easier during a refeed, but it does help me shed some body fat.

  51. Great article, thanks for lighting the way!

    I struggle with the proportions, personally. Im still finding my balance. There is a big part of me that just wants to eat butter & steak all day, because that is what I crave… and the other part that worries I am not getting enough veggies if I do. Dont know if that is my inner carb-addict talking.

  52. I’d love a response to my earlier comment…

    “Pro-carb bloggers however always refer to people in the far east who eat 500 grams of carbs a day (or something to that effect according to them). How do you explain that?”

    1. Kasha-

      In my experience, the perception that Asians (living in Asia) eat a lot of carbs is more anecdotal than factual. I’ve been to Japan and Thailand, countries where the diet is indeed based on rice. Rice was indeed eaten at every meal, but not very much. Maybe 1/2 cup or so, or about 25 grams of carbs. For 3 meals that’s still only 75 grams of carbs, which really isn’t much. And unless they are dining out at the now-ubiquitous KFC or McDonald’s, their overall carb intake is still quite low compared to the SAD. Of course, if you go to a Chinese or Thai restaurant here in the US, they are happy to give you big bowls of rice. Only Americans eat lots of rice, at least in my experience. I know I did years ago, before I knew any better!

      1. That’s true Rob. Same in the Philippines. Rice with every meal, but no where near what an American would typically put on their plate. And when I was there bread was pretty much a treat for tourists. Locals commented on my love for it. They are not loading up on carbs the SAD way.

        1. And, according to Konstantin Monastyrsky (Fiber Menace) white rice is actually very LOW in fiber.
          It does not cause any digestive upsets such as hard stools and constipation and moves through the bowels quickly.

      2. Also, factor in that people in Asian countries are poor, the cities are overcrowded and they WALK EVERYWHERE. 100g of carbs from white rice a day is easy to burn off when your source of transportation is your feet. Pair that with how pure and clean white rice is compared to wheat, corn, legumes and soy and you have basically an intake of nearly pure glucose. The only side effect of eating white rice is weight gain due since toxin levels are so low, but if you’re burning it off walking around, it doesn’t matter much.

  53. Good timing as there have been many blog posts of late that are re-evaluating the fat issue. Always good to see different opinions on an issue as important as this.


  54. Mark,

    Great insights on carb vs. fat metabolism. I think it’s a good rule of thumb when in doubt to ask yourself “what would Grok do?” Low-carb is the eating plan that we evolved on, so it’s no wonder that today’s high-carb diets cause inflammation and all kinds of other health problems.


    1. better still…. stick the skin under the grill until crispy and sprinklemwith sea salt. Now THAT is a chicken crisp!!!

    2. Just chose chicken that is free-range organic–lower in omega 6. Yum!

  55. Great post, Mark! I love any article you post that relates to metabolism.

    One point related to everything you said that wasn’t explicitly stated is that if our bodies, as CW insists, prefer glucose for fuel, why do we convert the excess to fat? As you said, Mark, you’d think we would have found a more effective way to hold onto copious amounts of this “prefered fuel” without having to convert it to something else.

    So our bodies are even trying to tell us something here that we stubornly try to ignore: “Hey, look, if you’re going to keep giving me this crap fuel, fine; I’m going to turn it into my prefered form of fuel, reagardless. Idiot.” 😉

    1. That doesn’t really follow; fat has a higher energy density by weight than carbohydrate so it pays to convert it, because you spend less energy carrying it around. That’s true regardless of whether it’s a better fuel for you or not.

      1. Actually, that’s one of the many reasons fat is the prefered fuel. Natural selection isn’t going to “reward” an organism that effectively stores massive amounts of glycogen and uses that as it’s primary source of fuel as much as an organism that efficiently converts, stores and uses fat, a macronutrient that as you pointed out is much more calorie dense by weight. You’re not really saying anything different from what I’m saying.

  56. Thank goodness for this post! I hope that some of the newer forum members are reading this. I have been seeing far too many conversations about calories and low-fat there these days. I actually saw one poster say that “75g of carbs is not enough to cover even your basic physiological functions!”
    Have they not even read The Primal Blueprint?!
    Thank you Mark for a well-timed post.

    1. Seeing a resurgence of low-fat talk, too. Wife’s frind, a skinny young lady, who is trying to “lose weight” pulls fat off thinly sliced grilled beef belly at the Korean grill house. It looks ridiculous, but I keep my mouth closed because I have learned that my wife and her friends are serious afflected by the the carb belief system.

      1. It’s like a cult all women are signed up to at birth. I feel her pain.

  57. I apologize if this is a silly question, but I have to ask. I eat a TON of veggies every day. Clearly, they contain carbs. I know it’s often said you don’t have to limit your veggie consumption because of how nutritiously dense they are, but I have to wonder, should I in fact be limiting my veggie consumption if I want to accelerate weight loss? How can I reach a state of ketosis when veggies are bringing my daily carb intake above 50 grams? Does Mark’s carbohydrate curve refer to total carbs or net carbs (subtracting out dietary fiber)? Any feedback from fellow PBers is greatly appreciated!

    1. You can subtract out fiber for sure. Fiber is indigestible and does not change your blood sugar.

  58. I’ve been low-carb primal for about 3 years now and recently added in more carbs like Sweet potato and even moderate amount of rice for some variety…I’m not athletic or particularly sporty. Not overweight either.

    I don’t quite understand why the Primal/Paleo-sphere is so insulin-phobic! Given that there are tons of ancient hunter-gatherer civilizations out there like the Kitavans, Hadza, Kung, and – more recently on the evolutionary scale – Asians, all of these peoples thrive on varying levels of “high-carb-ness” but are devoid of toxic neolithic “foods” such as gluten, high levels of omega-6 oils and sugar.

    Why does primal/paleo have to equal low carb?? It does not make sense to me. I find that guys like Don Matsz, Kurt Harris, Stephan Guyenet, Paul Jaminet and Richard Nikoley have a more balanced and realistic view on ancient nutrition than simply looking at effects on insulin and blood sugar levels.

    1. “Why does primal/paleo have to equal low carb??”

      It doesn’t, that’s just often the net effect. And that’s pointed out over and over and over and over by all kinds of people, including Mark. Ultimately, it’s about finding a balance within your environment that leads to the best possible health for YOU, which is measurable in many ways – i.e. via scientific methods and n=1 testing of your overall well-being mentally and physically.

    2. Have a look at the work done by Prof. Cynthia Kenyon of University of California about the effects of insulin on the body and life expectancy. Put her work alongside that of say Loren Cordain and the whole insulin/carb thing becomes clearer. The more we turn on our insulin, by eating carbs, the more damage it does to our bodies.

      1. All interesting stuff but still does not explain the H-G civilizations that thrive on high carb diets. There is a view that post meal insulin spikes are not necessarily the problem. Rather, elevated *fasting* insulin is. Big difference…are carbs *per-se* driving this? Don’t know, but I suspect that toxic carbs like fructose and wheat are the big confounders in this whole carb debate. It’s just like the CW folk lumping all fats together as bad. I just don’t see that safer starches like sweet potatoes and tubers etc, the staples of many H-G civilizations, are inately problematic. The “insulin hypothesis” of the paleo world does not play itself out in those societies who live on these types of foods.

    3. I don’t know what Asian countries you’ve been to where they are thriving, but to me most of them look clearly undernourished. They are very short and very skinny.

    4. There’s one thing you have to keep in mind: the Kitavans and other primitive peoples you mention typically eat one big meal per day in the evening. Their diet may be high in carbohydrates but when you eat one meal per day you only have one insulin spike per day so chances are you’ll never develop insulin resistance to begin with.

      If you’re going to compare a primitive diet with a western diet you need to take into account meal frequency. My guess is that once you’ve been on the Primal Blueprint for a while and your body is back to normal you can probably eat a rather high carb diet with no negative consequences if you eat one big meal per day (as long as you keep the food more or less primal).

      One big insulin spike per day shouldn’t send you on the road to insulin resistance but since there’s no precise way to assess if your body has been permanently damaged or not from all those years of breakfast cereals, sodas, wheat products, fruit juices, grain oils, etc. you’ll have to try it and evaluate how good it is for you.

  59. An excellent post and great comments. All around me, except one student of mine, gorges on carbs. I’ve just about convinced my wife to reduce hers but she just have to have bread(!) which pushes her daily carb intake up over 120 grams. I regulate mine to around 60 gms perday and have never felt better, fitter or slimmer, with no effort whatsoever. And here too in the UK everything on the supermaket shelves is ‘Reduced fat’ or ‘Fat Free’ and what folk don’t realise is that they take the fat out and replace it with carbohydrate! Love your Paleo I say!

  60. Chris Masterjohn, over at the Daily Lipid, has recently touched on very low carb/ketogenic diets. While it does show promise, he warns:

    “The body may be able to survive without dietary glucose, but only because it can make glucose from protein. Give it only fat, and it will make that glucose — and oxaloacetate — from lean muscle tissue.”

    In order to avoid muscle wasting on a ketogenic diet, there is strong evidence that either protein or carbohydrate should be included. For those in favor of keeping it low carb, of course protein would be the preferred choice.

    Either way, I’ve noticed improved health on a lower carb diet. Whether or not a 0 carb diet could work for me, perhaps a self experiment in the future could answer that question!

    Great article!

  61. The timing of this post is great. Men’s Journal just came out with an article entitled “The Man’s Guide to Carbs.” Of course, it parrots the CW regarding carbs. It’s gonna take time and continued education to change the CW.

  62. I recently watched an old Japanese comedy from around 1963. The father is gorging on rice at breakfast, and hands his bowl to his wife for a refill.

    She says: “You’ve had enough, dear!”
    The daughter chimes in: “You’ll get fat eating that much rice!”

    1. That’s how the Japanese have traditionally “built” 500+ pound sumo wrestlers. Just significantly increase the amount of rice and beer.

    2. it’s still common knowledge in Japan, I think. if you ever eat at restaurants there with a female, you’ll notice they give a half portion of rice to females so they won’t get fat

  63. Mark, hands down one of the most informative articles I’ve read on your site. It also is greatly going to help me to explain to my questioning friends/family why fat is better than carbs. I have one question though.

    I’m sure someone else has asked this and it might have been answered, but in the year that I have been following your site I don’t remember it being mentioned.

    At the end of the article you are mentioning the Primal Carb Curve and taking into account those that consume above 150 gms of carbs are probably predisposed genetically to weight gain AND “I am also factoring in the drop in metabolism that happens naturally with age”

    Can you shed anymore light on this metabolic drop with age? EVERYONE in society talks about it as they get older, but I’ve never seen anything about it being real. Does it only affect people running on carbs? I’ve been skinny my whole life and jealous coworkers always say “wait til you get older”. I’m eating very primal almost 100% with the occasional cheat. I did seem to notice that I was starting to add on lbs when I got to be 27 and had horrible nutrition and wasn’t being active. I’ve done some research online on the topic but would love to hear your take on it. What gives with our metabolisms slowing down as we get older?

  64. re: “It boggles my mind that such a large segment of the so-called health and fitness community would continue to defend high carbohydrate diets with such tenacity.”

    Look no further than the FDA/farming lobby/government schools/main stream media/food merchants.

    The health and fitness community, like every community, tends toward attachment to what is both familiar and promoted.

    1. People also refuse to do their own research. Its much easier to repeat society norms when forming opinions.

  65. I’m on the primal/paleo bandwagon, but there are still a few contradictions in the carbs arguments that bother me.

    1. This in depth, study-backed analysis of insulin makes a good argument that simple overeating, not carbs themselves is what leads to people being overweight.


    2. Looking at our closest evolutionary relatives, non-human primates eat tons of fruit nearly year round. Lots of carbs, but no weight problems. It seems likely that humans would be similarly adapted for lots of fruit.

    3. If the body burns fat so preferentially and efficiently, why can’t it be tapped for long-distance events like a marathon? lt seems like a contradiction to say that fats are such a great fuel, but actually if you’re a very physically active person fats won’t do and you have to go back to the carbs.

    Would be great if you could elaborate on these points in your next post.

    1. “3. If the body burns fat so preferentially and efficiently, why can’t it be tapped for long-distance events like a marathon?”

      I suspect the only reason our very ancient ancestors ever ran 26 miles was if they encountered a hungry sabre-tooth who was willing to go 25.

      1. More likely they were chasing dinner which would only run 25 miles. We lost our body hair to keep cool in those strenuous situations.

      2. “…. the only reason our very ancient ancestors ever ran 26 miles was if they encountered a hungry sabre-tooth who was willing to go 25….”

        Uh, no. Any quadrupedal predator could outsprint us in the first 100 yards. The predator, not the prey, sets the pace of the hunt. Faced with a sprinting predator, the prey MUST either outsprint it, or turn and fight.

        Our endurance running capacity can only be the result of us having been the predator, not the prey. And our slow sprint speed indicates that early on we must have found a way to make sprint predators afraid of us.

    2. Our “primates” have the hip structure of a dog, it’s tilted forward and they have a hard time walking up right.
      Also their digestive tract is a lot longer than ours. They also lack a tiny bone in the feet to accomodate walking upright.

      Primates are not our relatives. They’re a species all of their own.

    3. That weightology analysis sounds like a person who really wants to believe something, rather than one with a complete picture of the processes (not that anyone understands the body completely!). Read comment #10 by Matthew.

      I’m not sure what all the fuss is about a marathon – I’ve done a 1/2 and it was awesome to see I could, but it has no practical application to my life. Just because I could push my body to eat grains or run 13 miles at a time does not mean it’s good for it.

  66. I’ve been eating paleo for 10 days! I feel great but I do get light headed by afternoon. Not sure what I’m doing wrong. I follow paleoplan.com and use recipes from cookbooks. If I eat some fruit with nuts I feel fine after. I’m afraid from reading these comments I’m eating too much fruit (usually 4-7 different fruits a day). I do love fruit! This article is great because since I’m a newbie to this lifestyle I have been getting a lot of concerned questions and comments about my grain intake. I can’t find any support in my town they think no grain eating is only temporary. Are they right?

    1. Don’t be afraid to eat that much fruit if you are in the transition to a primal diet.
      At the beginning I used to eat a giant bowl of blueberries a day + 2 bananas and raw honey.
      It’s tapered off slowly. After a year and a month of being primal I now only eat 2 servings of fruit a day.
      Nuts and chocolate seem to trigger sugar cravings in me, not sure why, so I ditched those 2 things from my diet long ago.

      It took my body about 6 months to hit homeostasis.

      1. Thanks, that helps me feel better! I had just read all this again and had a conversation with some one right after about not being able to eat Paleo while participating in Crossfit. Anyone have any info on this?

        1. I can’t speak for them but my story was like this:

          Starting Primal I made it to week 3 and then completely lost it. I HAD to HAVE grains and sugar so I binged on mexican pastries for 3 straight days with no solid meals. After the 3rd day I felt miserable…it was BAD. I remembered how great I just felt for 3 weeks before going nuts from my cravings because I was days from my period.

          The next month was slightly better…I made it to the 3 weeks again and only indulged 2 days into mexican pastries but less of them + primal meals.

          By the 3rd month I had sworn myself I’d pay attention and ‘beat it’. Things didn’t really get any better until I found a farmer that sold raw goat milk.
          The raw milk had something in it that completely killed all my cravings for sugar and grains, chocolate and nuts.
          Another 2-3 months or so passed and I hit homeostasis.
          Now, while I was transitioning (and it took a loooooong time it seems) I had absolutely no desire to work out. I had no endurance whatsoever. I coulnd’t even sprint. I was nutritionally so crippled that my body took all its energy to rebuild my ‘crippled’ body back to life. I even had to start taking afternoon naps!!! It desperatly wanted to heal and I gave in.

          About 10 months or so into it I finally didn’t need naps anymore and I felt like sprinting and lifting weights.
          I now joined a gym (4 weeks ago) and I’m lifting heavy things and do my sprints up and down the stairs, I refuse to be on a treadmill. I’m starting to get some really nice muscles, I’m the only girl in there with biceps 🙂

          So you see, if someone just switched to primal, the body might not want to be using those precious nutrients for work-outs, but would prefer to heal first.

        2. Paleo/primal lifestyle and Crossfit go hand in hand. At my Crossfit box, we try to encourage people to go the Paleo/primal lifestyle. Those who do find their times and scores for all WOD’s get better after only 90 days.

        3. Finally! Some one answered my crossfit question! Thanks so much, I think I’m going to stick this out. I have not worked out and went jogging today ( I don’t run or jog) and I felt awesome! I have never felt so good attempting to jog. I ran longer than I ever have without feeling out of breath or exhausted! My dog was tired out before me!

  67. This is my favorite post in my year of checking the apple daily. And THAT is saying a lot. It is concise, educated and true on a fundamental level. Plus the embedded humor makes it fall in the play category. I’m so grateful for the important work that you and your staff are doing for our communal health. Here’s to the truth setting us free and here’s to Grok raising the cognitive dissonance stick against the mainstream.

  68. And this is exactly why I’m returning to school for a BS in Exercise Physiology and Nutrition – to change the system from the inside.

    Thanks as always for a most informative post Mark! I send people here first when the topic of diet comes up.

  69. Thank you Mark. Superb post!

    All this is such a huge paradigm shift so difficult to explain to our friends and family.
    Sometimes I feel I´m being regarded as some sort of fanatical Taliban when trying to explain it.

    It is incredible how difficult it is to even give it a chance, the benefit of the doubt!

    Sometimes I think we are like Columbus explaining that the earth is not flat.

  70. Part of the brilliance in being human is that we can adapt and even thrive on a wide variety of macro-nutrient ratios.

    It is folly to think that a single ratio is correct for a certain individual. I would bet that anyone could adapt to a reasonable ratio falling predominantly into any one of the big three (carb, fat, protein) and be healthy.

    High protein, High Carb, High fat, you name it, someone’s lost weight on it and improved their health markers. You can find past and current cultures that thrive in any of these categories.

    Unfortunetly we cannot find any culture that thrives on nutrient deficient industrialized garbage that make up the typical SAD diet…

    1. Exactly!! If this is the case, why the demonizing of starches and insulin by the paleo community? Why does the default position of the paleo/primal “blueprints” and “solutions” etc have to be low-carb when there is vast evidence of high carb eating ancient societies?

  71. It never ceases to amaze me how much backlash comes with the recommendation to control carb intake. I suppose this can be explained by how they are supposed to have an addictive effect. Its too bad that more people dont just try Marks recommendations instead of continuing the path they are on.

  72. The human body is adapted to eat a varied diet out of necessity. In my opinion this doesnt prove that we can either function optimally eating high carb OR high fat.

  73. Thanks, Mark! I will be seeing you on Wednesday in New York for the Q&A on just this subject, and this got me even more fired up to go!

  74. THANKS MARK – this REALLY helped me. But could you use some more sources? Some claims you made like “your body runs on fat not glucose” I could not find backed up by a scientific explanation, if you know what I mean.

  75. Ancient societies eating high carb are NEOLITHIC..we’re going back a little more in time to Paleolithic..which is higher fat and lower carbs…HOW many of you know the difference?

  76. PB has worked wonders for me and I’m a true advocate. I have a dirty little secret though…I love carbs. I know, I know. I should go scourge myself right now, but I just can’t seem to kick cereal. Probably one of the worst things I could eat.

    I have seriously minimized how much I have though. I’d say about 80% of the time I’m under 150 grams of carbs a day.

  77. My weight loss coach has me really watching my carbs. I went off sugar which was really really hard for me. But she lost 100 pounds eating 6 small meals. Being in her 40’s I read about her on-line saw her before and after photos and thought why not we are the same age and I have to get weight off per dr orders and wanting to be here for my 5 kids. Jill has been a great support. You really actually have to see her before and after photo to understand what I am talking about. she is at getupandgetmoving.net
    Your information is great. Thank you!

  78. Excellent post on the metamorphosis we all undergo by following the PB! Explaining the reasons why a glucose metabolism is so detrimental to our bodies for the masses that continually buy that failed logic is paramount. Thanks for putting it layman’s terms for all, Mark.

  79. I would say that generally speaking this is a great advice for normalizing and improvings one`s metabolism.

    Perhaps there is a bit too much preferance on fats but that can be understood in the light of oppostion to general public dietary guidelines.

    But – it is very important that BOTH fat and glucose metabolisms are functioning AT THE SAME TIME. This cannot occur when one isn`t adapted to efficient fat burning.

    Rejecting fat or carbs (which is not the case with PB – 100 to 150 grams average of starch and sugars from fruit seems very appropriate for the majority of people) can be dangerous and can severly damage one`s health.

  80. How long is it supposed to take before your body starts working normally again after you go PB? I’ve tried PB/LC a few times for a few weeks at a time, but always had to cut it short after I ended up with severe brain fog and absolutely no energy (and severe sugar cravings). And I wasn’t even very low carb at around 150g a day.

    My heart also beats extremely hard when I eat a lot of meat. This feels scary and makes it almost impossible to sleep. It goes away once I eat more carbs.

    ‘Primal Palate’ wrote that it took her many months of PB to reach homeostasis. It would be great if others could share their transitional experiences as well.

    1. You will experience brain fog and lack of energy. This happens while your body adapts. You have to get past that.

    2. Hey Don,

      It took me a few weeks of feeling REALLY poor then a couple months of slowly feeling better day by day. I didn’t get that “wake up one morning and feel awesome” thing like I see a lot of people write about. I’ve been primal for almost a year now. I’m almost 40 and feel better than I did when I was 21. Seriously.

      I feel your pain though, sugar withdrawal is just plain not fun. Bacon helps a lot, don’t be shy with it.

    3. Don’t worry — it happened to me too. There is no need to push through it… every time I got scared from being so foggy I went to Taco Bell and had 3 tacos and a pop. I was thinking things just weren’t going to work out… Well the taco bell trips ended up being further and further apart, from every 3rd day to every other week… and now I haven’t been there in a month and I’m totally fine on like 50g carbs today. No suffering through mental fog to make it here. Just persistence with returning after my Taco Bell breakdowns.

  81. Mark,

    I feel like there’s much evidence to the contrary that there is any one preferred macronutrient fuel for the human body.

    Dr. Guyenet has shown several examples of healthy high-carb cultures. In populations not predisposed to metabolic disorder due to their whole foods and traditional diets, perhaps lots of starch is fine.


  82. HI..Has anyone here ever heard of Charles Darwin? He had a theory about location and evolution..
    I’m pretty sure that where we live and the generations of our Ancestors in these locations…along with the food they ate and eat is why cultures in different ares of the globe can consume different foods and thrive…America is very young and the people are from everywhere…and this Agro-business diet has shown that we are some of the most messed up…
    I eat tons of fat and very few carbs and am strong as an ox..can go for days without much food at all…and have noo problems sleeping or eating or thinking…I am PRIMAL/PALEO stock..it shows very clear to me..So do yourself a favor..MANAGE this..keep track of your food intakes..It is SIMPLE diet-exercise and a way of life you can tune for you to be in the best health and eat well and live well…EVERYONE is different..find your slice of the Primal life and live it..GROK ON>>>

    1. Bruce,

      Generally speaking when you consume 50 or less carbs per day your liver runs low on glycogen and starts producing ketones. Ketones are made from fat. This is why people talk about being “fat adapted”. It is the process of “weaning” your body from using carbs to using fat for fuel. The liver will also produce glucose from free fatty acids in a process known as gluconeogenesis. This is a beneficial state because it burns fat AND the conversion isn’t efficient so it has to use a lot of fat to do it.

      I.F. stands for Intermittent Fasting. A daily 20 hour fast would be considered intermittent and would definitely help you get into ketosis faster.

  83. To the poster who made the comments about paleolithic vs neolithic “ancient” societies….does it really matter?

    We live in the present and adaptions have taken place whether or not your inner “grok” wants to acknowledge it or not. We have 8 times the concentration of amylase in our saliva than apes. Guess what, this is irrefutable evidence that we’ve adapted to eating starchy tubers. (Carbs!) And not just a few either…

    Like I said earlier, you can find a culture that has thrived on a diet falling predominantly into any one of the big 3 macro-nutrients.

    So can paleo be low carb? It can. Can paleo be high carb? It can. We need to remember that paleo is a “time period” not a “diet”. Diets have been and will always be varied. The only thing unavailable in the paleo time period is the industrialized processed garbage that makes up the majority of the SAD diet.

  84. One of the proofs given to me that obesity causes T2 Diabetes is that 45% of diabetics are overweight or obese. Well then, that should prove that slenderness causes diabetes too, because 55% of diabetics must be either the right weight, or slender.

  85. Could someone give concrete examples on what the different levels of carbohydrate intake would look like? I don’t have any concept of what a gram or 50 or 150 grams of carbohydrate a day would look like. How many grams carbohydrate is fruit?

    1. For example:

      1 banana = 7g sugar + starch (complete 10g)
      1 small apple = 5-7g sugar
      1 serving Berries = 5g sugar

      Total sugar (carb) consumption coming from fruit = 20-25g

      Do not consume more than 20-30g of total fruit sugar in one day.
      Approx. 2-4 servings of fruit a day.

      That’s on top of having liberal amounts of vegetables 2x a day with your main meals and perhaps a handful of nuts.

      You’d total about 50g – 75g of Carbs a day.

      1 cup of Raw dairy is about 11g I think.
      When choosing Yogurt pick one that’s plain.

  86. As a truck driver I often stop at convenience stores for snacks during my work day. About five years ago I noticed that I was losing weight without really trying, a good thing since I was packing around an extra 30 pounds. Now whenever I put back on those extra pounds I go back to what worked before. A low carb but filling snack of “pork rinds”. Limit my beer and bread intake along with more pork rinds and pounds begin to go away.

  87. Mark
    Again, another great post! I bookmarked it so that I can e-mail it to some workmates.

    They look at me so curiously when I do stuff like scrape the toppings off the pizza (I am not gluten-intolerant), or take a lunch sandwich and scrape the meat off and throw away the bread (you know – the crap that they feed you when you have a lunch meeting)! (lol)

    You are going to not like this, but, I am having some success by uptaking my carbs through a banana and raw legumes/vegetables (5 days/7 for lunch). I know you aren’t freindly towards legumes, but those raw snap peas (or garbanzo beans when I treat myself) are so yummy!

    Evenings (when I can get it down) and weekends are meat-centric (if I even eat at all).

    It isn’t just that I like my vegetables raw (taste matters!), it is also that it is my enzyme replacement therapy. And for enzymes, the food must be raw (below 104 degrees). High enzyme and flora lead to a healthy immune system.

    And despite a fairly sedentary lifestyle (not enough high intensity work) (retired Ultimate disc & 10K racer), I am still getting a fair report from the doctor, to wit:

    – triglycerides 44,
    – LDL just above the optimal level, but particle size is large,
    – could lose about 10-15 lbs (of fat), but also would need to add about 10 lbs of muscle to be in the “sweet spot”

    Just a note, I know how much you disdain legumes, but I thought you might be willing to hear an observation of how that is working out. Maybe? Where you get your carbs does matter? I don’t know – it is something that I am still confused about…

    1. I forgot to add. I also eat a lot of peanuts (yeah, I know, yet ANOTHER legume!). Peanuts w/ skin on b/c of resveratrol (beats red wine or grape skins!). I mix it in with other nuts (pecans, walnuts, and cashews).


    2. You sound like an old fart with a stubborn brain, and you are paying wayyyyy too much attention to individual nutrients. You do realize that there are hundreds of nutrients in food, right? Nutrients that have yet to come out with fancy names and studies? Buzz off.

  88. Wow, That was a really good post. Even though I am in Fitness, I don’t restrict my self of things at all carbs or fat as long as I am eating healthy foods. Years ago I tried cutting down on carbs but I couldn’t work out as intense as I liked. Now I just try to listen to my body, if I feel I need to eat carbs I do, and If I feel I need to eat something with fat in it I do as well. Thank you for a great post

  89. When I changed my eating life style to meat and veggies and a few fruits, I found I have a hard time getting to 100 grams of carbs a day, let alone 150 grams.

  90. What I’ve found is the main problem with any lifestyle, be it paleo, vegan, vegetarian, is the holier than thou attitudes. Even in this post, everyone’s like, “This is sooo obvious! Why doesn’t it anyone get iiiiit, everyone else is so duuuumb” (I’m paraphrasing; stay with me!)

    The low carbers think they’re right. Vegans think they’re right. Vegetarians think they’re right.

    Lot of references to the average American. What about thin non-Americans? Someone who eats moderate fat, moderate carbs and protein in “standard” ratios of 40-30-30 and doesn’t have weight or health problems?

    A girl can run herself ragged trying to find the right thing to stick with. I’ve flirted with vegetarianism. Couldn’t do it. Won’t even touch veganism. But I’ve never liked meat, so what to do? I like chicken, but I can only eat so much of it before it gets boring, even with a multitude of recipes on hand.

    I don’t believe in very low fat (wtf, at 80/10/10!??) Never again. But low carb also makes me feel like shit, too. Could I get some general guidelines on increasing according to activity? Please don’t ask me to experiment. Being as lean as I am, I’m afraid to experiment and lose weight (be it muscle OR fat), but I’m having a hard time finding a good balance for maintainence.

    1. Hi Lisa

      I think the balance is the key. Like you I have tried being a vegetarian, I also experimented with cutting carbs, but nothing worked for me a well as a simple balanced diet. I don’t like restrictions, but I also eat pretty healthy due to my eating habits growing up. I have to say that I am very lean, and I believe I got that way by not restricting food groups.
      All though it is bad to over indulge on complex carbs, such as white bread, rice or pasta. But fruits and veggies, I eat in crazy amounts.

  91. @Lisa — “The low carbers think they’re right. Vegans think they’re right. Vegetarians think they’re right.”

    Yeah, well, that’s the nature of religion. Or the “belief engine” that Tom Naughton talked about on the 4th Annual Low-Carb Cruise. I have had fantastic results from low-carb, but it’s not the answer to life, the universe, and everything — there are still pieces of the puzzle missing. It’s not settled science.

    I’ve been blogging about my own low-carb journey at guestdietblog.com. These days, I’m tending toward low-carb paleo, except that 50-100g/day is not really low-carb. I’m thinking of it as “right level of carb” at least for me, and the SAD is just ridiculously high-carb (with a boatload of HFCS).

    When I went low-carb in 1999, I avoided the “Atkins Flu” by keeping a detailed diet log for a few days to establish a baseline, then cutting back gradually over a period of a little over two weeks. The feel-bad period from cutting back on a really high-carb diet is about the same length as the feel-bad period you get from quitting smoking, and I suspect it’s pretty much from the same cause — breaking an addiction.

    1. @Howard – whoa, chopped a part of my comment off before posting. That’ll teach me to not proofread…

      What I meant to say was, those have worked for a lot of people. So to say flat out that vegs are totally off the mark is a little unfair. Though I have to admit a lot of the vegans I know are either overweight, sickly thin, or just sick all the time because of low immunity.

      But if a person is reaching their nutritional targets, does it matter if they do it with a lot of veg, fruit and tofu and not a lot of meat?

      Vegetarian is failing me now; carbs aren’t really an issue with vegetarianism, but fat is! I’ve had to up my fat intake because I was, like a lot of other veg women, getting irregular cycles before they stopped entirely.

      But daily, I pretty much get around 130-150 g of carbs daily. I haven’t gained or lost weight, but I know when I’m on the lower end of things, I don’t always feel well. So it doesn’t sound like a case of breaking an addiction to carbs.

  92. From what I get to hear a lot..Im never right..LOLOL Life itself is an experiment …Im afraid we all have to experiment ..for there is nothing written that pertains to us all…GROK ON>>> however you do it…to each his or her own…And dont forget the Bacon…

  93. I could not DISAGREE more. High fruit, LOW fat, raw vegan diet is the way to go if you’re looking for not only a lower body weight but also vitality and stamina. Read Douglas Graham’s book 80-10-10. This high fat diet you’re promoting is just giving people an excuse to keep eating animal products, which are high in saturated fats and cholesterol, not to mention antibiotics and growth hormones. You can throw scientific data and any diet, but to claim this is how humans are SUPPOSED to eat is riiiiidiculous. Humans, before all our conveniences had to find food to eat. That was mostly fruit. Look at the way anthropoid apes eat (these animals are closest to humans.) Very high carbon diet (fresh, raw fruits and vegetables.) Less than 1% of their diet is comprised of insects/rodents. Pound for pound, they are 5x stronger than humans and have no real need to even drink water since all the water they need comes from the raw fruits and veggies they’ve been eating all day. I’m sad at the number of people who read his article and now feel enlightened.

    1. Sunny: I’d suggest taking in a class in either biology or botany. A diet consisting of mostly fruits would mean to starve in any northern states. Ever eat Peaches in January in Ohio? Or how about fresh cherries in October?

      Oh, and bananas don’t exist in Michigan. 4million years on this planet walking upright was not because of your of your “riiiiidiculous” enlightenment experiment. Go get all hippy on some other zen internet forum.

      1. I wonder if the “fangs” we have are for something else… because I have seen the show about Chimps hunting down and eating other primates..
        And …there sure are a lot of fruit trees out on that African Savannah and up in northern Europe….we GROK ON>>>

    2. Sunny, did you know that you could not find a fruit like you know 10,000 years ago? Nor could you find most of your favorite vegetables. The fruits you think apes eat are mostly bitter, hard and small compared to the “candy on a tree” you may be used to. Secondly, look up the behavioral changes that enabled our fuel hungry big brains, the literature usually mentions breaking bones for marrow and cracking skulls for brains. That’s all about the fat. I was a vegan for 35 years and it almost killed me the last ten. Returning to an ancestral diet saved my life.

    3. So we used the spears and arrowheads to reach all those apples and cherries on trees.
      I guess I could get good at throwing arrow heads at a berry bush…it would take a lot of practice though.
      All those american indians that killed all those precious animals just for their fur (hmm, reminds me of something).
      And all those eskimos that kill all those fish for thousands of years to try and rid the ocean of its ‘pests’…those darn fish just won’t stop coming back, will they.
      And the primitive australians killing kangoroo for the flesh, errr I meant fur…

      No, we did not evolve eating meat at all…I guess non of these cultures got your Memo…eh?

    4. Sunny, I got sick from trying to keep my fat that low. Yes, even with higher carbs. It worked for awhile but I found it impossible to sustain.

      Fruit and veg are awesome and I love them, but I really disagree with 10% fats. When I was keeping my fats at 20-25g daily, I was cold and irritable all the time. I was underweight because the drastic cut made me lose a little, and I never needed to in the first place. I was weak to boot, which was the worst, because I’m normally athletic.

      I’m not saying you need to go and eat meat, but once I played with the fat intake a little, I felt a million times better. I just make sure 20-30% of my calories come from fat now. Little extra olive oil, more tofu or tempeh, anything helps.

    5. Chimps strenght is their downside. They can’t make delicate, precision movements, necessary for advanced tool making. They are also horrible throwers. This is because in chimps a small number of neurons controls movement of large number of muscle fibers. This gives an easy way to get 100% of muscle strenght utilized by firing a limited set of neurons, but means no fine control.


      Humans are supposed to be selected for having a large number of neurons thanks to the requiements of hunting by throwing. Throwing has accuracy requirements that grow with distance, and unlike in moving across the trees there is no possibility of last-milisecond corrective movement.


    6. No. And I’ve read that back in the primal days, fruit as we know it was not easy to come by. The fruit you see today was all modified and selectively bred.

      And I would strongly caution eating massive amounts of fruit unless you can point to a study that shows the body handling the sugar from whole fruit differently from refined sugar.

      Fructose greatly accelerates glycation.

  94. Daniel Merk… Hippy police. I have too little time this morning to go into eating what’s in season and remembering humans didn’t start out in cold climates such as the Midwest. I would like to recommend the book titled, “80-10-10” for anyone looking to be UNbrainwashed by the meat and dairy industries… or maybe you could read it for the sake of playing Devil’s Advocate.

    1. So it looks like more meat for us……dont forget the bacon!!!!
      Your talking to the wrong crowd here…go talk to a vegan page…we have more books than your one …and they are written by PHD’s and others who have done the homework…AND..you forgot to say”organic”
      if your so TUNED into that routine…

    2. Sunny, your theories on your vegan experiment/spirituality movement doesn’t interest me. Was a vegetarian for 10 years and was tired of being sick. Good luck with your experiment. We’ll see ya in a few years when your bones break and your hair keeps falling out. Biology tells us this.

  95. Keep destroying the planet to satisfy your appetite. You’re right. The meat and dairy industries can just buy us a new earth when this one is tapped out. If your TWO pansy ass, tiny little canines and your lightning fast speed and razor-sharp claws (haha!!) Are enough of a reason to pretend to be omnivores, cool. But your cooked, seasoned, sauced-up meat is not the caveman diet you’re all so proud to be following. True carnivorous can hunt, chase, bite into and rip apart an animal. They devour every trace of meat in their bones, including their face, eyes, guts, etc. All RAW. I dare you to kill a chicken and then eat it’s flesh. You know what? Even try boiling it before you eat it to make it more tolerable. It tastes like shit. Be meat lovers. Go ahead. But claiming it as natural to the human race is a joke. Calling on evolution to make a point is showing a misunderstanding of the way evolution works.

    1. You can’t seriously claim that humans evolved being vegans?

      On the other hand I understand what you mean. If we keep promoting this way of eating within a short amount of time we’d be out of resources.
      We are already short on resources, that’s why there are feedlots and empty oceans.
      People need to stop having 3+ children. Population control is in order.

      Also, Mark Sisson doesn’t promote a high meat diet, in his book (which you probably haven’t read) he states that the bulk of the meals are supposed to be vegetables!

      Most of us here don’t buy feedlot meats and chicken from commercial stores fattened on soy. I agree, that type of chicken does taste like shit!

    2. And – forgot to meantion this one, we do have Vegetarians on board of the primal diet, too.

      Primal/Paleo just means cut out things we didn’t evolve on FOR SURE, which is grains and processed sugar.
      Can’t argue with that. You can be vegan and primal.

    3. We agree. The dairy and meat industry is indeed taxing the planet. But on this forum, we work with farmers, not big agri business. Also, this forum is all about veggies and animal protein. Lastly, don’t fool yourself into thinking that by giving up on animal husbandry the plant farmers are going to save the planet. Just about every species smaller than a cat suffers. There are plenty of books on the subject.

    4. Ah – and there it is…

      If vegetarian eating is about health – why do you lot ALWAYS default back to the ecology argument!?

      You have NO understanding of evolution if you think that the fact we no longer eat meat raw is proof that we are not meant to eat it.

      We CAN eat meat raw, and if we couldn’t cook we would. But cooking makes food easier to digest and enables us to access nutrients in foods we could NOT otherwise eat.

      What is more an issue is you are so dogmatic about your view, you FAIL to recognise when you are making points against your own argument..

      NO OTHER ANIMAL cooks it’s food!!!

      Why don’t you eat all your food RAW!?

      Tell you why:

      1) Potatoes – inedible
      2) Wheat – inedible
      3) Corn – inedible
      4) Rice – inedible
      5) Legumes – inedible

      In fact ALL the above are either poisonous or at a minimum toxic enough to make you VERY sick if you don’t cook them!!!

      Most primates are omnivores. Humans do not require claws, as we can track and hunt and even use tools. Additionally, opposable thumbs mean all primates can hunt without claws.

      Our digestive tracks are FAR too small to be true herbivores (i.e. only eat green leafy matter and fruits).

      Humans CAN get by eating the above GRAINS, as despite our anatomy that is too different from animals that are are truly able to eat plants, these food sources give us energy quickly enough to be useful… but they ARE TOXIC raw!!!

      So it is impossible for a human to be a vegetarian, because for those of us that UNDERSTAND evolution:

      1) prior to eating grains (10,000 years ago) eating only vegetables/fruit would meant starvation

      2) And prior to 50,000 years ago we could not cook our food, so we couldn’t eat the grains and legumes and potatoes etc listed above that are toxic for humans when eaten raw.

      So why don’t YOU eat your food raw?

      You wouldn’t survive without MODERN farming giving you YEAR round fresh fruit.

      If you just ate vegetables, with NO grains you could NOT survive.

      And as to your environmental concerns – you are completely ignorant of the FACTS

      1) Corn and soy farming causes some of the WORST environmental degradation of land on this PLANET – PERIOD.

      2) CORN/Soy/Grain fed animals are definitely a problem for the health of our planet and our own health

      3) Cows, chickens, pigs, sheep etc raised on GRASS are environmentally GOOD. This is a fact. There were up to 60 million bison in North America roaming the plains.., the reason the plains of North America were so fertile was due to these animals.

      Where ever on the planet there are NOT grazing animals the land DEGRADES to arid land…

      Grazing animals provide part of a CHAIN of life.

      You pseudo greenies that use your eating habits to push a flawed agenda, do not TRULY understand ecology, you have a “religious” or philosophical belief, and you use emotion (like your rant above) to push your agenda and try and make people feel guilty…

      Well go actually learn about ecology and nature AND Evolution…

      You will find that you disgust for meat eating is so fundamentally FLAWED. The fact is – without meat eating animals and humans the planet would not have as much biodiversity as it does today.

      Of course I am wasting my time on you (but perhaps not some other person reading this)… as you would NEVER give up your belief system – no matter what the ACTUAL FACTS…

      1. This is a quote from Mark; The lion’s genetic makeup was shaped by meat-eating. Its teeth and claws are made for killing, its digestive tract is meant to process protein and fat. You might even say the lion’s genes expect the ancestral lion diet of raw meat and function best on such a diet. Conversely, a diet that diverges dramatically from the ancestral lion diet will probably be harmful…”
        Humans do not have this make up, we do not have the digestive system to eat meat, we do not have the teeth. Look at a carnivore’s teeth, nothing is similar. I do believe that we should not eat any type of grain, it wasn’t around as we evolved. I think eggs, nuts, seeds, fruits, veggies, fish, anything that was easily available to early humans is what we should eat. Agriculture is destroying our plant and health. If we did not eat meat, there would be no negligible pollution. 90% of the worlds agriculture is for the animals people eat, not for humans. Only 10% is realized back in the form of a food that is not digestible, unless cooked, and unhealthy for humans. The beef industry pollutes, uses more energy, more fuel and more fresh water than all other reasons on earth. We already eat too much meat . Why do you need all this fertile land if we do not need the agriculture? Just to pollute the planet? If you cook anything over 104, it looses any benefit for nutrition. The human body actually functions best on fruit, it digests and gives you energy in 20 to 30 minutes, veggies take 4 to 6 hours and meat never really digests or gives you energy. Your argument about athlete’s don’t matter because very few are, what about those that are? Try eating anything but fruit before a day of high exertion and see what happens. Digestion is the #1 user of energy in your body, about 75%. You only have 25% left to perform if you ate meat, even the day before. I believe a lot about this PB diet, everything but the meat! There is far too much evidence against raising, grazing, feeding, torturing and murdering animals for man’s food, health, pollution, ethical and moral issues to think that is acceptable. almost all the meat available is garbage because the animal was fed grains that it is not supposed to eat. And given drugs and steroids to help it survive and make it fat. I am 66 years old and still perform better than most teenagers at an extreme sport that requires more physical conditioning that any other for over 45 years. I have not ate any meat in 30 years and stopped grains 5 years ago, mainly the PB diet without the meat. I am in perfect health and have never taken a single drug of any kind. I am totally NOT religious either, morality does not come from a god. Those are the actual facts.

  96. I think this is dangerous. To write such and article with spiritual consepts and just play it on your way of eating as its the new jesus. This is just redicoulus. It harms the body, people and the planet. Do you really want to smell like dead animals? kill young animal babies so you can get their milk. Please share some real facts that has been published and supported of all this claims. Not just some paradigm bullshit shift that you claim. If its one thing that has increased around the world the last years is meat and dairy and animal products in total. The results, the world a sicker place. People doesnt have empati, their ego is bigger then the planet. They rape, kill, does whatever just to satisfie their ego and status.

    1. “kill young animal babies so you can get their milk.”

      “People doesnt have empati”

      “They rape, kill, does whatever just to satisfie their ego and status.”

      What are you, 12?

      Check out some conspiracy theories by Jessie Ventura, you’re really gonna flip.

    2. There has also been a increase around the world in the last years (speak English much?) of corn, soy, wheat and rice products in total – so all the raping, killing and satisfying egos must be due to those things!?

  97. What are your thoughts on Ezekiel bread as an alternative to breads?

  98. Sunny — I find it funny that you are telling people to read 80-10-10 when you haven’t even finished the book yet.


    Maybe we should eat a shit load of fruit and end up like this kid…


    Or maybe we could eat 4000 calories of fruit a day and gain 60lbs in less than a year like one of your “peacekeepers” on 30bad did. The crazy thing is…instead of telling her to cut back, the cult members are congratulating her on her weight gain?

    If my wife gained 60lbs in a year I would throw her ass out. 🙂

    1. Holy Cow? What did I do to screw that UP? Doh!

      But anyway, a healthy diet starts off w/ EATING UNPROCESSED FOODS!

      It is a major pain, and it takes a lot of time – but that is the first step – for you and your children.

      You do prep cooking on the weeekends – USING REAL (store bought) foods – and they you prep it.

      You DON’T JUST eat a veggie-only diet; & and you DON’T just a meat (& fat) only diet – YOU EAT THEM ALL!!!!

      It is a balance! A balance set forth from our primevil (sp?) heritage.

      Dudes! We ate meat & we ate vegetables!

      And the latter we ate RAW! (Enzymes)

      And the latter led to a healthy gut (along w/ a rad-hard ample supply of bacteria!)

      Which led to a healthy gut!

      Which led to a healthy immune system!

      And the rest led to healthy brain function (saturated fats), healthy bone & muscle development (fats as well as meat protein)

      So please check out HOW you are DOING IT before you make your disclaimers!

      HOW you eat your veggies, HOW you eat your meat – MATTERS (and ob btw, I HATE non-extinct dinosaurs called CHICKEN – yuk!) – I want meat from mammals – just like we used to eat about 4 million years ago – KAY?

      It is about eating a DNA sequence that closely resembles my OWN!

      best, Iluv

  99. Most of us go through rough times trying out different diets and lifestyles. Most times we get disappointed when the promised healthy results doesn’t show up or when health degrades after years on a typical wondrous diet. I am no exeption. 2009 I and my family went LCHF – Low Carb High Fat (Sweden). And it was good,initially and especially for me with a history of dieting away even being a raw foodist.I thought that finally I can eat FAT, BUTTERS and CREAMS without guilt or fear.Suddenly I was more accepted by friends and familys. But that didn’t last long. And thank God for that…I only regret that i didn’t listen to that little, little vioce whispering to my logic much earlier but all in good time, right!? Well, I developed a tremendous thirst for juicy, ripe fruits(?)I became constipated, aching from a new kind of fibromyalgia (wow)all over my body, dandruff, slow minded/thinking and other weird reactions. But, what else to eat!? Fruits are dangerous, fats are dangerous, not this and that…total confusion and disappointment. ‘Til I onne day surfing around the Internet for SOMETHING, I hit Freelee’s vids. I recognized the message but never fully understood. Today, I follow the 80/10/10 almost 100% and can experience results already! But fruits are dangerous!? Hm – nope. I thrive on them, Freelee does and many many more – perhaps even LONG term. If so, I can only work for enlightning the world and ask of Gods blessig to do so. Live a little; is a very good saying. Yes, let’s live a LOT, eating whole fresh ripe products without blood, pus and suffering…Love and Peace, over and out ?

    1. Interesting. I have been following LCHF for a little over 10 years now (back well before it got to be popular in Sweden), and I have not experienced any of the problems you described. I would suggest you post this to https://www.dietdoctor.com/ which is a blog run by Andreas Eenfeldt, MD, a Swedish doctor. I had the pleasure of meeting Dr. Eenfeldt on the 4th Annual Low-Carb Cruise.

    2. Lena, I’m glad you found something that works for you but hope that you supplement and please do keep track of your blood sugars.

      Looking over the 80/10/10 diet, I notice that most of the food is not available locally for 3/4 of the year in my area (probably even less in your region). My food is all grown locally, sustainably, organically while your’s was mostly flown in from monoculture farms cut out of the rainforest. I’ve seen the deer, rabits and birds coexisting with my food, while your food requires massive wildlife death to make way for tractors, trucks and airplanes. Mine requires 1/1000 the fuel as your food to transport it to my table.

      If you are ethnically Swedish, it is even less likely that you are adapted to a Fruitarian diet. Good luck, and God Bless, but seriously, check your A1c often.

  100. Very interesting read and enjoying all the comments. I have a HUGE hate for how almost every lunch bar / cafe / restaurant bases their meals around carbs, pads all their salads out with pasta, rice etc. and it’s soooo hard to buy decent protein when you’re out and about. Luckily I learned to cook and now take my own food with me everywhere. I just wish more food places would stop pandering to everyone’s ‘carb addictions’ as I love eating out but it’s so hard to find good low carb choices. I feel much better on high protein and looooove coconut and nuts, and train so much harder and feel better and lighter on a 50 – 100g carb per day diet. Thanks Mark for your honesty and explanations!

    1. have cooler…for travel…
      we think along the same lines..
      I keep my carb load at the zero to 50 range…And never have any problems with lifting- moving- thinking- grokking…GROK ON>>>

    2. It’s all about cost. Carbs are CHEAP food, and those restaurants are making money by feeding them to us. Adding a cup of pasta to a salad is far cheaper than adding a cup of chicken. It’s all about dollars and cents, and they could care less about our health.

  101. Been Primal for a few months now. In general I feel great and I’ve lost a decent amount of fat, but I have to say it’s been a real challenge finding the right balance of carbs to both promote fat loss and at the same time prevent burn-out from exercising. I know carbs are not suppose to be necessary, and my workout routines are Primal, but I really do notice a positive difference when I consume things like sweet potatoes after workouts. I do not consider myself necessarily an athlete, but I do lift heavy things about three days a week and move around enough other days, so I would love to hear more on tips for balancing fat loss with exercise on a Primal diet.

    1. Remember that Primal cuts out grains, legumes and processed sugars.

      You can eat potatoes and fruit. Especially if you lift heavy things and need the glucose for your muscles…they recover much faster with a little help.

      I’ve read that only people that want to trim down to an unhealthy level of body fat do 3-4 days of low carb meals + work outs…followed by 1 day of high carb meals (rice, potatoes)…followed by 1 day of Fasting.

      This is supposed to bring your fat % way down…your blood sugar took a dumb after the high insulin meals of the high carb day and now if you don’t eat the day after that your body has to burn fat to produce normal blood sugar levels again.

      4 days low carb, 1 day high carb followed by 1 day fasting…rinse repeat. You can make it 5 days low carb if you’re counting weeks.

      The rest of us who don’t care about a 5 or 10% body fat can eat potatoes and still be way under the average SAD’er.

  102. Okay, how about this scenario:

    Take two people.

    Drop them in the woods, say, 200 miles from the nearest civilization.

    One is given a bag of corn starch.

    The other is given a gallon or more of any kind of fat you choose.

    Each must hike to civilization eating only their macronutrients. One can only eat fat, the other carbs.

    Which one do you think will make it first?

    My point being, carbs provide a better fuel source for metabolism than fat does.

    I would bet the house that the corn starch fed hiker gets out first.

    This is backed up by any elite level competitive athlete, anywhere. NONE eat a low carb diet. NONE.

    1. OK, three days later we find the cornstartch man less then halfway there, still trying to choke down a dry powder, but the animal fat, *ketoadapted* man simply emptied out the fat, used the bucket for water, and walked fasting three days until he reached civilization. A fat burning metabolism will not run out of energy (at any reasonable walking pace) until all fat stores are depleted. Sugar metabolisms run out every couple of hours or so.

      1. No, my point is, a carb burner will be able to hike faster. Sure, the fat burner may be able to go longer without eating, but as long as the carbs are available, the carb burner will be able to hike faster.

        Corn starch is easily assimilated mixed with water.

        And, again, no elite athletes eat low carb. WHY IS THAT?

      2. Oh, I see your point. You say that since the corn starch will weight a lot, and the fat burner will not have to eat as often, the fat burner will be able to hike faster because they can just eat a bunch of fat then ditch the rest and keep hiking without food.

        It really depends on what kind of survival situation. Long term, ketosis may be a better state for survival in famine, however when the need for explosive activity arises, like fighting a mountain lion or sprinting, the carb burner would fare better.

        You’ll never see a Mongol wrestler on their traditional diet winning the UFC.

    2. “My point being, carbs provide a better fuel source for metabolism than fat does.

      I would bet the house that the corn starch fed hiker gets out first.

      This is backed up by any elite level competitive athlete, anywhere. NONE eat a low carb diet. NONE.”

      There is a difference between ideology and evidence. Unfortunately for you, the evidence is much more equivocal and indicates that a high-fat diet can indeed play a large part in preparing endurance athletes for competition. Specifically, in several studies there was no statistically significant difference in the performance of athletes using both HC and HF diets. Just for starters: https://home.trainingpeaks.com/articles/nutrition/fat-and-the-endurance-athlete.aspx

      There’s plenty more available if you use your webz foraging skills to expand your horizons beyond vegan sermons and echo chambers.

    3. “This is backed up by any elite level competitive athlete, anywhere. NONE eat a low carb diet. NONE.”


      How about world-class Swedish triathlete Jonas Colting? He is on the record as stating that a high-fat, low-carb nutritional approach has not only improved his health but also maximized his athletic performance in competitions. He has won the Ultraman World Championships in 2004 and then again in 2007 as well as high finishes in the Long Distance World Cup in 2001, 2004, and 2005.

      Also I do recall a female low-carb athlete at least placing )if not winning) a recent iron woman championship…

      Also – to your experiment, if already adapted to their diets (switching off carbs takes 2-4 weeks to detox) then the guy with the fat will win – PERIOD. He (or she) will even likely have fat left at the end (a gallon is a LOT of energy (fat is 9 kcals/g – compared to carbs being 4 kcals/gm) Meaning your carb person would have to carry DOUBLE the weight (assuming equal density of food calories) to have the same number of calories.

      However even if not adapted – your experiment is flawed. If they have enough energy with them – they both get there.

      Lastly – as has been suggested, if someone is already n fat burning mode, then they can EASILY dump the gallon of fat and just run unencumbered by any additional weight.

      A 75kg (165lbs) man with 10% body fat has 7.5kgs (16.5lbs) of fat to burn… if they have not been eating carbs, and hence switched into fat burning mode they can EASILY use their fat stores as energy.

      200 miles would require maximum 28,000 kcals (assuming 25yo, male, 5’11” running at 7.5 miles per hour for 30 hours (allowing for SOME rest – as 30X7.5 is more than 200 miles, so the kcals required is LESS than that)

      With 7,700 kcals for 1kg (2.2lbs) of fat, this 28000 kcals would burn 3.6kg (7.9lbs)

      Leaving 3.6kg body fat, which equates to 5.5% body fat remaining.

      If eating the carbs – they would need to CONSTANTLY stop and refuel, as their bod would not be able to easily access body fats…

      The reliance on carbs for these events is evident to ANYONE that has used a carb gel during a long race.

      Even for a marathon (42.2 km/26 miles), runners have to dose up on carbs from gels or drinks… so 200 miles would definitely require the same regular dosing.

      In competitive sports there is no doubt carbs give bursts of energy, which results in performance, but so do steroids, doesn’t mean it is good for you.

      Fact is NO ONE has done the proper trials to check who would win in your scenario.

      However this study did look at runners:


      Only issue is everyone is so indoctrinated into believing fats are bad, that “13 runners failed to comply fully with the third regimen, complain- ing that it was too fatty, even though they gained no weight”

      The third regime being “45 percent of calories” came from fats.

      Results are there:

      “At the end of the two fattier diets, the athletes increased the amount of time they could run at peak capacity by an average of 7 percent—or about 30 seconds. Overall endurance increased 14 per- cent, and exercise-induced muscle fatigue decreased. Moreover, the study found that runners who consumed the fattiest diet used their stored energy more efficiently than they did when on the lowest-fat diet.”

      May have been better if the morons worried about eating fats had complied, instead of believing the DOGMA that fats are bad.

      So let’s set it up, with a high carb and low carb athlete… still willing to bet your house?


  103. Actually they won’t have to eat any fat at all. If they are already ketoadapted, they can burn body fat as easily as dietary fat. Look on the first pages of this thread and find the youtube link to the hunter who ran down his prey over 8 hours with just water. Carb addicts can’t do that. As for your “Elite” athletes, the paradigm has not yet shifted, so of course most athletes follow the outdated carb loading advice. That’s called “Argument by Authority” and is a fallacy used when the facts are not sufficient to support the contention. I suspect that if someone points to an athlete who does eat low carb, you will shift the definition of “Elite” until it excludes that person.

    1. No, if they are in ketosis, they will NOT be able to push as hard as the person burning carbs.

      Call it whatever you want, if the paradigm shifts and gymnasts, boxers, wrestlers, and sprinters start using fat as their primary fuel, I will eat my words.

      But they won’t. It will never happen. Look, don’t you think that if fat was a better fuel source, elite athletes would be using it by now? These are people that will go to no end improving their performance by any means. Of course they would have changed their diets away from carbs if fat is better.

      Put a 25lb sack of corn starch on my hikers back, and they will hike out faster than your ketosis hiker who carries NOTHING. All else being equal, both being people of average fitness.

      Again, I would put money on it.

      The burden of proof obviously rests on you, since no current athletes run on ketosis (unless they do and don’t talk about it).

      1. No current competitive athletes that is, IE the ones who win.

        THat includes sprinters and endurance athletes. If fat adaptation is so much better, why wouldn’t marathon runners on an olympic level do away with gatorade type drinks? After all, they make a living, many from poor countries, competing. Seems like they would make any adjustment in macronutrient ratios necessary, but still they carb load and drink sugary drinks and gels.

        1. carbohydrates serve well as a fuel when you are doing high intensity activity because glycogen oxidizes as fast as you take in oxygen, and that’s what you want when you are doing high intensity heavy breathing activity. and the body has limited stores, hence why athletes refuel often.

          but day to day, a diet that is high fat, low to moderate carbs increases stock performance.

          So yeah, use carbs for high output activity if you want.

      2. I could ask you to prove that none do, since there are some on this board who do. But no one denies that carbs are a faster burning fuel. But you have switched from a 200 mile hike, to fighting mountain lions to sprinting. In the rare instance that you have to fight a mountain lion, maybe a handful of berries is a good idea. For most of typical human endeavor, and for long term health, fat is the better fuel.

        As for proof, I don’t need to be convinced. I am on record (in another forum) for fasting three days and maintaining my level of exercise. Not “Elite” by any means, but beyond normal daily levels by quite a bit. I posted detailed records of activity and BG readings. If you want to find out if it’s possible, you will have to make the experiment yourself.

        1. There is nothing to prove. Ask any elite athlete what they eat, and they will say carbs. Of course I can’t prove that ‘none do’, so you will have to be satisfied with the vast majority.

          And no, I still argue that a carb burning hiker could go 200 miles faster than a fat burning hiker, all else being equal, and given the carb burning hiker had access to carbs.

          Berries are nothing, barely any calories in them. Corn starch would be leagues better as a fuel source for high intensity exercise.

          The proof is in the (high sugar) pudding. If fat was a better fuel source, for explosive or endurance exercise, world class athletes would have made the switch.

      3. Man I don’t really want to step into this, but there are athletes that are currently doing paleo and talking about it.


        Additionally, many of the elite CrossFit guys run pretty strict Paleo.

        I’m not saying there’s not a place for carbs – no one is. In fact, all the big players in this (Loren Cordain, Robb Wolf, Mark Sisson) all advocate carbohydrate intake in addition to protein and fats. They also advocate more the more active you are. They just don’t advocate the carbs found in grains and legumes.

      4. Put a 25lb sack of corn starch on my hikers back, and they will hike out faster than your ketosis hiker who carries NOTHING. All else being equal, both being people of average fitness.

        YOU HAVE NO PROOF of this…

        You are taking what you know/believe.

        Why are there no athletes doing this?

        1) the entire SPORTS industry believes what you believe!

        The coaches and nutritionalists don’t know that they could do things differently.

        As you your mountain lion scenario – endurance is different to sprinting… and in a sprint situation, fats are a great fuel

        Also, your belief has been disproven… look at the links to the information people have posted, including the one I gave you above – both endurance and ability to maintain peak speed improved!!!

        2) regarding the gatorade thing – I’ll tell you why – cause gatorade couldn’t earn millions selling people sugared water if people realised a steak with some fats would mean you can perform without their product!!!

        The entire FOOD industry is skewed towards corn, soy, wheat and SUGAR – PERIOD… and they love having unquestioning lemmings like you that spout off about elite athletes as a reason to keep eating their crap.

        3) Even Mark (the author of this post) notes that if you are doing a lot of exercise, or competing at an elite level you can up your carb intake, because carbs are a cheap easy (and nasty fuel – like I said steroids get great performance – but not good for you)… But here is the FACTS, 99.99% of the population are NOT elite athletes – not even near it… and even more so more than 99.99999999% of the population will never be in your silly hike test, and even if they were – it would be ONCE.

        Actually the burden of proof rests on YOU… Just because a infinitesimal percentage of the population that engages in elite performance sport MAY (and again – it is yet to be properly studied) be better off using carbs as an energy source, the fact is this is NOT what normal life is, and so the burden of proof is on you to prove the higher carb, low fat method is good for everyone else, because ever SINCE we adopted the approach you are advocating (and ever since the likes of gatorade started selling their drinks to people that DELUDE themselves into thinking they are some sort of athlete) obesity, heart disease, diabetes, cancer, stroke, depression, crohns disease, MS have been on the rise, and it can be traced in nearly every country to when health authorities in each country started advocating the low fat – higher carb food pyramid…

        And anticipating you will bring up sedentary lifestyle… explain how before the 1970’s obesity was rising at a pace only a fraction of what it is today (increased sugar consumption – but no low-fat higher carb diet recommendation until the mid 70’s), yet belonging to a gym was near UNHEARD of, doing yoga, pilates, private personal training session – all the same – nearly ALL organised exercise just didn’t exist… the fact is in terms of total hours spent exercising there is MORE for a lot of people – and they are STILL overweight.

        It is DIET… you cannot out exercise poor diet and poor diet includes carbs – and ever since we were conned that carbs are good the WHOLE world is getting fat!!!

  104. OK, yes, if you manipulate the test until only a carb diet will be best, then the carb diet is best. Do you, in reciprocation, agree that if you don’t manipulate the test, if you only speak about the average person, the average athlete, in average circumstances, who wants more than to simply excel in a limited endeavor for a short span of years, that for this 99.99% of humanity, fats would be the better fuel?

    For instance, obviously LOX rocket fuel is a better fuel if you want to shove multiple tons off the Earth, but for driving around in daily traffic, gasoline is better and less likely to erode your car’s pancreas. What’s best for an abnormal person in an abnormal situation cannot reasonably be declared to be what’s best for all people.

    For the record though, for a long time, the best athletes in the world advocated cigarettes and beer. I’ll go with the biochemistry over athletes recommendation every time.

  105. Elite athletes stress their bodies in ways not necessarily healthy. Mark and pretty much all low carb/Primal/Paleo experts have repeatedly said that higher carbs are necessary for those athletes that insist on or are required to train for abnormally high amounts of time. See, for example, The Paleo Diet for Athletes. The whole point, that you’re missing, is that Mark is not concerned with fueling an elite athlete lifestyle because, again, elite athletes arguably put their bodies through unhealthy levels of stress that are dangerous in the long run or near impossible for the ordinary human to maintain.

  106. To more fully answer the question, “Why don’t elite athletes use a low carb diet:

    Matt posted a fair and full response, but I want to say that perhaps they would try it – if the zeitgeist of the carb-loading athlete were not so strong. Pair that with the commercial drive to push the limits of human performance beyond normal limits and you have carb loading, steroids and other damaging methods. Does adding nitro to your household car improve speed bursts? Yes. Is it the preferred method of fueling your car? No.

    We may never know what athletes can do on a more evolutionary diet. I don’t expect the pendulum to swing that far back in the 20 years I might have left. It’s been 12 years since I left the carbohydrate addiction behind and I still can’t find a doctor who supports me in my diet, even though they hold the records in their hands. The CW, the myths, the USDA guidelines are just too strong, and have have the full force of Big Agri/Pharma Lobbyists behind them.

  107. I wouldn’t eat corn anything even if you paid me to….
    specially corn starch..
    choking down starchy dust?…not for me…Primal man did just fine without it and man can continue to do just fine without it..And some of the most EXPLOSIVE athletes I know..Eat Paleo/Primal …especially the Crossfit monsters…And I know em…and they wouldn’t eat corn anything either…

  108. Of all the things many humans, and particularly Americans have “forgotten” how to do, eating, tops the list.

    Extrapolate that across all of human activity and I shudder to think what that spells for us.

  109. Of course, one thing I have to admit is that in nature, carnivores are NEVER able to outrun herbivores. Not ONCE, EVER! Which is why all carnivores died out so many millions of years ago…

  110. How much can you increase your intake if you’re working out? Even on workout or really active days, I stay around 150, occasionally a bit higher. Still too low? Sometimes I find myself hitting a wall…

    1. I think you have to play with it in order to figure out what is optimal for you and your level of activity. If you find yourself bonking out, then you probably need more easily accessible energy, and since it takes work and time to get additional energy out of fat, it makes sense that the body would preferentially select ready to go energy. So if you need more, take more in. Stop when you feel better.

      1. Looks like 170 is a good area for me, surprisingly! Might want to rethink 170 as an insidious weight gain zone. 😉

  111. I just want to make a small contribution to this thread in terms of “our neolithic ancestors” and high carb diets.

    I am an academic working cross-discipline in history, literature, classics, and politics, with a specific interest in the lives of the ordinary working classes from the classical period to the 19th century West.

    What people maybe do not realise is that, even two hundred years ago, “bread” was nowhere near the kind of product we produce and consume today.

    If you recreate the ingredients, which is possible in Britain as we still have a few working watermills with traditional mill stones to create the right kind of flour, and methods by which Western European people made bread in the early 19th century, you end up with a very dense, compact, heavy, close-crumb product that is very “meaty” in texture.

    It is very difficult to eat more than a couple of slices of these loaves, and they were made with traditional honey, not refined sugar. They were also very small, compared to what we see today. Remember also that the “white flour” of the time was not bleached, just sieved, and cost a premium that many could not afford. Cheaper flour was could be up to 50 percent husk.

    To go back to Tudor/Stuart England, the diets of rural English peasantry revolved around what they could grow in their small cottage gardens and what they could forage in forests. These people lived on bone broths with scraps of root vegetables and meat, and dairy products if they were wealthy enough to own a cow or some chickens. There were oats, however.

    Again, if you were wealthy in the Tudor/Stuart period, you ate meat. Lots of meat. All the time. In fact, what is noticeable is the link between obesity amongst the elite and merchant classes and the consumption of ale, beer, mead and wine.

    So it is not really accurate to say, if you are from a Western European heritage, that our “ancestors” in the last 1000 years ate high carb diets. It really depended on who you were, and where you were. Indeed, most non-elite/non-merchant class English people prior to the 19th century lived on what we would probably see as a rather Primal Diet — remember there is no rice, no pasta, and, before the Tudor period, no potatoes, and honey is the sweetener of choice. Pastry is made with lard or suet, and they didn’t really eat a lot of it.

    1. Hi Alex,

      Nice points you raise.

      The other issue is that even if you take the 10,000 years generally accepted as how long the human species has been eating grains, this is not as long as it sounds from an evolutionary point of view.

      If you take modern humans being about 200,000 years old in terms of physiology and metabolic functions, then 10,000 years is not that long. Put it on a 24 hour clock (NOT a 12 hour clock) and that means that we have only been eating grains for the last 72 minutes (out of 1440 minutes)!!!, or approximately 1 hour in the last 24.

      Now we may have adapted to tolerate this food source and certain individuals may even have genetic variation from the norm that allows them to THRIVE on this type of diet, but based on human history, and even allowing for the observed acceleration in evolution for humans in recent times it will likely be another 50,000+ years before we would have a sufficient portion of the population that has evolved to be “homowheatus” as I like to call them, and that would thrive on a high grain diet.

      Note the difference, in biology you can adapt to tolerate something, that does not mean you are at the point where you have evolved to THRIVE on that thing.

      Anyway, as you point out, few people would have appropriately adapted to a high carb diet within a 1000 year period.

      Also, the other common mistake people make when first reading about the Primal Blueprint or similar diets is that they think the no grains approach in the Primal Blueprint means low/no carb diet.

      It just means lower carb. With carbs still coming from non-grain sources. You limit your carbs by not eating grains and refined carbs of any kind.

      You can eat fruit, unless you want to maximise weight loss, and thus limit your carbs even more.

      At not stage (other than small fasts), do you reduce you carbs below an amount that could keep your brain ticking along on carbs if needed.

  112. i didn’t read all of the pages of comment, so please forgive me if i’m redundant, but i highly recommend Sally Fallon’s “Nourishing Traditions”. it talks about what healthy historical cultures *really* ate, and one cookbook you have to read cover-to-cover! it’s co-authored by Mary Enig, who probably knows more about dietary fats than anyone in the world.

  113. I have a simple question: if fat is the preferred fuel, and you follow PB nutrition, then why do you state “There is a downside, however: you can’t train long and hard day-in and day-out in the fat paradigm”? Don’t all of us have plenty of fat to supply energy for endurance training?

    1. I work HARD…and I lift HEAVY…and I pretty much live on less than 50 grams of carbs per day..everyday.I have no problems GROKKING along…Everyone comes from different evolutionary genetic stock..and we all are different and can
      handle it different.
      FAt…CArbs…PRotien…just do it fresh and with no processed foods.GROK ON>>>

  114. This post is ridiculous. The body requires carbohydrate for brain function, which is a physiological priority. The body doesn’t prefer fat and ketones (ketone bodies are derived from fatty acids when carbohydrate in the body is scarce; a desperate mechanism to get a form of carbohydrate for the brain). Here’s an experiment to find out what fuel the body prefers: keep insulin (a protein hormone that facilitates the transport of glucose (carbohydrate) across cellular membranes) away from a type 1 diabetic and see what happens.

    Fat does become the predominant fuel used by muscle at low levels of physical activity, but it is not preferred, but only to spare carbohydrates for moments when it’s critical (physical activity/survival).

    1. @Seth: It has been determined by real scientists, using real science, that the brain functions just fine on ketones. You are free, of course, to continue on your superstition-based diet if you so chose.

      1. Actually, no it hasn’t. Do you have any idea how and why ketone bodies are produced in the body? Please cite the research article(s) by these real scientists demonstrating that the brain is okay with just ketones.

        1. Do you have any idea why type 1 diabetics go into a coma and die? It’s not superstition, it’s education.

        2. If carbohydrates are so necessary to the human body, how did we survive the last ice-age?

        3. And you are confusing ketosis with ketoacidosis. Different conditions, different diets. Ketoacidosis is only dangerous for diabetics.

  115. Almost a custom for those who disagree with a well reasoned, fully documented and entertaining post to repeat assertions we’ve all heard many times before, as if repeating them makes them more like science. For the record, the body can and does produce all the glucose it actually needs, so dietary sugars and carbs are not needed. Any amount of blood sugar over about a teaspoon full per hour is toxic, as many reputable news sources are finally admitting these last few weeks. That’s why we have insulin, to move it out of the blood, and keep it form killing us. That’s why T1 diabetics need shots of it, not only so that they can use the sugar, but so that it’s not in their blood, killing them.

    1. Wow.

      Sugar in the blood will not kill you. Excessive amounts get excreted in the urine.

      What reputable news sources?

      1. Yes, blood glucose levels for diabetics are never checked and a high number is not at all worrisome.

    2. As a current doctoral student in human physiology, previously completing a masters degree in exercise physiology, I’m telling you that you are completely misinformed. This is a perfect example of the misinformation floating around out there concerning metabolism. The striking part is how the misinformed cling to it and believe it.

      1. As a graduate of a degree with biochemistry and evolutionary biology, and someone with experience in the pharmaceutical industry (now out due to what I now know) and working in the area of Type 2 diabetes, I’m telling you that you are completely misinformed. This is a perfect example of the misinformation floating around out there concerning metabolism by those indoctrinated in the conventional wisdom of exercise physiology (i.e. personal trainers with an degree). The striking part is how the misinformed (especially those climbing the academic ladder of the conventional wisdom) cling to it and believe it (without question, cause it is already in my head!!).


        Too easy

        1. I recognise you are getting your doctorate in human physiology, but obviously that means you get to skip the basic information on physiology…. otherwise you would/should have learnt about things like the role of the hormone insulin in promoting fat storage and preventing fat burning, the lack of a decent glycogen storage system (despite your dogma that carbs are vital – of so vital we would have evolved a decent carb storage system to rival fat storage) and the fact that evolution for nearly all animals chose FAT as a storage mechanism, hence it must be fine to run your body on fat!!! Oh and the completely one sided view of energy in = energy out, ignoring (or being ignorant of) the fact this equation runs both ways and describes a relationship, not a cause.

    3. Bill DeWitt:”For the record, the body can and does produce all the glucose it actually needs, so dietary sugars and carbs are not needed.”

      yes and it’s one of the reasons why we survived those thousands of winters. Our ancestors’ brains didn’t stop functioning properly when we had to rely on hunting & fishing (zero carbs) as our only source of food for months. The “You need X servings of carbs or you’ll die!!!” crowd needs to look at evolution & how we survived in the past, not at the USDA Food Pyramid/Plate.

  116. So when my vegetarian diet led my BG readings to be in the 700s instead of around 100, you are saying that this was not a problem? Can I quote you on that when they schedule my amputation?

    As for reputable news, Look it up. There have been plenty of links posted. That way you can use YOUR idea of a reputable source. But look for hyperglycemia, not “why sugar is good for you”…

    1. No, I don’t condone a vegatarian diet, nor did I even mention it.

      You made a claim that sugar is toxic and that this information supported by reputable sources. You should provide the source.

  117. Argument by Authority works a lot better when you cite your sources and offer your credentials…. still a logical fallacy, but one that fools more people.

    1. haha – you must cite your sources!

      I don’t have to, because I’m educated!!

      I don’t know if you are educated too, and even whether you are MORE educated than I am, but as I am brimming with self pride in my academic “achievements” I will ASSUME that I must be smarter than you (I mean I have a masters and am studying a doctorate – what are the chances you are “smarter” than me!!!)

      I fail to recognise that obtaining a qualification does not equate to experience of even knowledge in the real world.

      I also fail to recognise that whilst in common language having a masters and studying a doctorate is considered being “an academic”, in academia, until you have done research, preferably resulting in some new facts being revealed to the world, not just confirming what is already known (or worse assumed), you aren’t really an “academic”.

      However, most people assume people with degrees, especially advanced degrees are smart, so they will be swayed by my use of my qualifications (completed and currently underway) as proof enough of the facts I state!!!


  118. Unless your plan is to avoid the question, the type of diet is not important. Tell me you believe that a BG reading of 700 is not a problem, or admit that hyperglycemia is one of the major causes of the eventual death of T2 Diabetics.

    If you have not looked up hyperglycemia by now, then you don’t want to learn, you just want to argue.

    1. The major causes of death of type 2 diabetics are heart attack and stroke, not hyperglycemia.

      A BG of 700 is not good; it’s a problem. A BG of 700 doesn’t happen because carbohydrates are bad; it happens because of a poor diet and no exercise. A BG of 700 often occurs because the individual is insulin resistant (again, due to a poor diet and no regular exercise).

      I don’t need to look up hyperglycemia. Also, I always like to learn. That’s why I’m a graduate student.

      1. Ah Seth,

        The graduate student makes you a master of all information.

        Well I have worked with, and learnt from some of the leading endocrinologists and other specialists in the world that treat Type 2 (and Type 1) diabetes, including some at institutions such as the International Diabetes Institute.

        Your statement:

        “The major causes of death of type 2 diabetics are heart attack and stroke, not hyperglycemia”

        …is like saying the leading cause of death for gunshot victims is ingress of a bullet, not the firing of the gun.

        The damage to the vascular system, including the regulation of blood pressure by the kidneys is damaged by CHRONIC hyperglycemia. As a result after YEARS of elevated blood glucose (hyperglycemia) the damage to the vascular system results in heart attacks and strokes. DUH!!!

        Regarding your hypothesis that high blood glucose only occurs due to poor exercise and diet – again this is FALSE (e.g. Type 1 diabetics).

        You state “No, from an evolutionary perspective, we are all the same.” Whilst there is some truth to the fact we all evolved from likely a single female human ancestor, it is also a fallacy to state we are all the same in terms of evolution… CLEARLY there are physiological differences between people, some due to race, yet even within a race, there is genetic variation (in fact the variation is larger within a particular race). If you TRULY are studying to attain your doctorate in human physiology, I really do hope they teach you this basic fact. Even in conventional medicine it is recognised that certain people react differently and metabolise certain compounds differently from others. Proof of this is the fact that some people can take a drug with no effect, others taking the same dose can end up with severe side effects and even be so sensitive they die… clearly we may have a common evolutionary source, but we are NOT the same in terms of evolution, as environment and other factors shape our evolutionary path.

        You state:

        “The body requires carbohydrate for brain function, which is a physiological priority. The body doesn’t prefer fat and ketones (ketone bodies are derived from fatty acids when carbohydrate in the body is scarce; a desperate mechanism to get a form of carbohydrate for the brain). Here’s an experiment to find out what fuel the body prefers: keep insulin (a protein hormone that facilitates the transport of glucose (carbohydrate) across cellular membranes) away from a type 1 diabetic and see what happens.

        Fat does become the predominant fuel used by muscle at low levels of physical activity, but it is not preferred, but only to spare carbohydrates for moments when it’s critical (physical activity/survival).”

        SO MANY errors here it will take some time:

        1) Even if the brain needs carbohydrate as a preference, this does NOT equate to needing carbohydrate in the diet. It is a medical and scientific fact (and no I have no references at hand, as this is considered BASIC common knowledge – especially for someone as “educated” as you) that there are NO essential dietary requirements for carbohydrates. There ARE essential amino acids and fats, without them our bodily function is compromised. There IS a process in the body that converts proteins into carbohydrates (gluconeogenisis). This is a function of the liver, and is in fact one of the dysfuntions Type 2 diabetics suffer (their liver produces excess glucose, even when the blood glucose levels are already elevated). This is such a significant problem, that many of the new drugs for Type 2 diabetes under development target this process. If there is sufficient protein in the diet (in excess of basic needs), any excess can be converted into glucose vis gluconeogenisis. This is why body builders that eat too much protein, don’t realise most of the excess is pissed out or converted into glucose.

        The “experiment” is SUCH a fallacy and an example of poor debate on your part. Type 1 diabetics have a VERY different aetiology to Type 2 diabetics, and if you are in fact as educated as you claim to be you SHOULD know this, and as such you are either truly ignorant, or being deceptive so as to confuse those that may not know the difference.

        Type 1 diabetics have a condition that means their pancreas no longer produces sufficient insulin (if any at all). In the absence of ANY insulin, the body cannot utilise glucose. Additionally, as there is no insulin the bodies fat cells are signalled to release fatty acids as a energy source, and the type 1 diabetic quickly emaciates, additionally in certain cases they can enter diabetic ketoacidosis. If you do not know this, diabetic ketoacidosis is NOT the same as being in ketosis.

        The key here is the “acidosis” in ketoacidosis. All acidiosis states can be lethal (there are others other than ketoacidosis). They are essentially acidification of the blood.

        This is NOT the same as having ketone bodies in your blood stream, to suggest so is misleading.

        From wikipedia:

        “There are two major causes of ketoacidosis:

        Most commonly, ketoacidosis is diabetic ketoacidosis (DKA), resulting from increased fat metabolism due to a shortage of insulin. It is associated primarily with type I diabetes, and may result in a diabetic coma if left untreated.[4]

        Alcoholic ketoacidosis (AKA) presents infrequently, but can occur with acute alcohol intoxication, most often following a binge in alcoholics with acute or chronic liver or pancreatic disorders. Alcoholic ketoacidosis occurs more frequently following methanol or ethylene glycol intoxication than following intoxication with uncontaminated ethanol.[5]

        Ketoacidosis may also result from prolonged fasting or when following a ketogenic diet.[6]”

        I have included this last statement, as it is true, it MAY result from following a ketogenic diet, however you would have to be following it in the EXTREME. In fact outside of alcoholics and type 1 diabetics it is VERY rare, and even for them it is not at all a very common medical problem.

        You state:

        “You made a claim that sugar is toxic and that this information supported by reputable sources. You should provide the source”

        Two things here:

        1) Whilst I do not have references at hand (I am in a hotel at the moment), look up glucotoxicity. Again, in research with non-diabetics, pre-diabetics, Type 2 and type 1 diabetics there is evidence that elevated blood glucose (and not even that much mind you) has DIRECT glucotoxicity effects on the pancrease, in particular the beta cells (the VERY cells that produce insulin, which would in some way reduce the problem). This, as one professor in the area mentioned to me, is the great irony of the human body, the very cells that produce the hormone to reduce blood glucose are themselves DAMAGED by excess blood glucose. As a result if they fail to keep up with the amount of carbohydrate consumed (simple, complex, low GI or high GI – they ALL end up as glucose), they then get hammered, resulting in a reduced ability to keep up in the future. In fact, this fact suggests when we evolved we were not consuming vast amounts of glucose, if we did, there would be another mechanism that would have evolved to accommodate the beta cells that were damaged. We never evolved this system, because we never ate vast quantities of carbohydrates until we worked out how to access the carbs from the previously toxic grains and legumes we learnt how to cook enough to reduce their toxicity.

        2) You admonish others for not supplying references for their claims, yet you have NOT ONCE done the same. You use your education as you reference. Well sir I will invoke the same as you. I invoke me degrees in biochemistry and evolutionary biology, and years of experience in the pharmaceutical industry (reading countless journals in this topic), as well as my working in the area of type 2 diabetes. I acknowledge I don’t have a masters or a soon to be PhD, but then again, perhaps that is why I am not caught in a delusion that everything I learnt is absolute truth, and I don’t have the neurosis of using my education as a crutch to remain blinkered to any other views of the world. The fact you are a recent graduate and straight into a doctorate suggests to me you are someone heavy with education, but lacking life experience.

        You state you KNOW better than us because of what you learnt in attaining your masters degree in exercise physiology and during your current studies to attain your doctorate in human physiology… what an appalling state of affairs in the education system, when such an obvious flaw in your logic is beyond your recognition.

        What if what you have been taught is wrong? Just because you have a degree (masters or even doctorate) in bullshit, doesn’t make the bullshit any less composed of faecal matter from a bull!!!

        As this post points out, the conventional wisdom (i.e. what you have been taught and re-taught without question) is WRONG.

        Instead of trying to understand WHY this is different to what you have been taught, and instead of seeking new knowledge, you simply jump to the defence of what you already know!! What a poor standard of doctorate they now provide if you NEVER learn to ask whether the current knowledge is actually right!? That is the POINT of being educated, having the ability to question, not just defend what you already have in your head.

        Finally, the issue you and all your exercise and human physiology lecturers have failed to recognise is a few simple questions:

        1) If are bodies are incapable of utilising fat as an energy source (as is suggested here), and MUST have vast amount of carbohydrates in order to function – WHY did evolution for ALL animals choose fat storage as a survival mechanism? The human body, and that of most animals stores a pathetically small amount of glycogen (stored glucose for those unaware of the techno talk) in the muscles and the liver mostly. If we needed carbs to survive, ALL animals, including humans would have evolved a better and more capable glycogen storage system!!! This is just LOGIC – don’t need a masters or PhD to work that out!!!

        2) Again, if we NEED carbs to function, and especially the brain, then HOW did we evolve and grow most of the increases in human brain function during a period when we would have had LIMITED access to carbohydrates?? Prior to the utilisation of grains approx. 10,000 years ago (or at a stretch 30,000 for a single tribe as was recently discovered), there are little to no other significant sources of carbohydrate for the human species. By 50,000 years ago we had evolved way beyond apes and already had language, music, and other complex brain functions. HOW if what you say about carbs is true? ALSO how did we survive as a species in colder climates with limited access to even green leafy plants for significant portions of the year if we NEED carbs to function? We survived because proteins and fats and organ meats give us the necessary amino acids, vitamins, minerals and essential fats we need. The protein also provided a means for the liver to utilise gluconeogenisis to provide whatever carbs need we may have had in excess of the ketones our bodies and brains can use.

        3) If carbs are so good, why is it that since the advocation of high carb/low fat diets the rate of type 2 diabetes and obesity has skyrocketed? This is a FACT, look at the epidemiology data. In cultures where this was not advocated until later, the increases came later. This is NOT just due to lower levels of physical activity, as even in populations where physical activity has increased, the switch to higher carb diets has resulted in increased type 2 diabetes and obesity.

        Finally – The fact is insulin, which is not excessively excreted when there is less carbs in the diet PROMOTES fat storage in the body. This is one of the MAIN functions listed for insulin in almost ALL biochemistry and endocrinology texts. When insulin is present, fat cells are signalled to STORE fatty acids and convert glucose to fatty acids to store them. If you want anecdotal evidence of insulins weight promoting ability, ask ANY GP, endocrinologist, diabetes educator/nurse or diabetic. As SOON as someone is put on insulin, even if they exercise MORE than they did previously and eat less, they will put on weight. Of course it is HARD for them to eat less, as another problem with insulin is that it can OVERSHOOT the reduction in blood glucose, leading to hypoglycemia (blood glucose too LOW) which is at best dangerous, and worst this is FATAL. As a result, with blood glucose too low, the NATURAL response by the body to this problem is HUNGER (this is BASIC physiology – I trust you understand this – if you don’t HAND YOUR MASTERS back and save your money on your doctorate and go back to some 1st year biochemistry). As a result, the subsequent weight gain is an insidious cycle, as the insulin promotes fat storage of the calories consumed, and then lowers blood glucose, resulting in hunger and calorie consumption, and then the cycle repeats.

        IF you had actually WORKED with any type 2 diabetics, you would know that not all are just lazy as you suggest. Sure, some are, but here is the kicker, one of the effects of HYPERglycemia is lethargy, which leads to reduced caloric expenditure, which leads to higher levels of hyperglycemia.. again another twisted vicious cycle.

        Also recent research in Type 2 diabetes has demonstrated that regardless of blood glucose level, the use of insulin is associated with an increased risk of heart attack and stroke.

        OK, the real finally – the conventional wisdom that it is only overeating and laziness that causes type 2 diabetes and obesity is ignoring the fact that the energy systems (i.e. metabolic pathways and feedback loops) are not unidirectional. And this does take some understanding of thermodynamics (which I learnt in biochemistry – did they teach that in physiology?)… but the equation flows both ways.

        Gary Taubes has a great explanation of this, but essentially you are applying causation, when all you can observe is a relationship.

        If you say calories in = calories out is the equation then the equation works both way, i.e. calories out = calories in!

        So if you eat 2000 calories and then use 2000 calories you end up net zero. However it works the other way – if you USE 2000 calories, your body needs 2000 calories, and so it seeks 2000 calories. We know this is true, as people like Micheal Phelps eats many times the normal calories, due to the caloric expenditure he has. The calories USED DRIVES the calories consumed.

        Continuing, less calories in = less calories out, again in people that are starving, this is reflected in lethargy.

        So what about if you eat 2000 and you expend 2000 calories, BUT 200 (10%) calories you eat get stored and locked away before you can use them (and this is WHAT excess insulin does, it stores the calories BEFORE they can be used – it lock away fatty acids). Now you have used 200 calories more than you have available, your body has TWO possible responses:

        1) Eat 200 calories more (with 20 (10%) stored like before), so you need another 20, with 2 stored, so you need another 2 – all up an extra 222.2 calories consumed, with 222 stored as fat. This manifests in the “real world” as someone “overeating”


        2) you reduce your energy expenditure to 1800 (with the 200 still stored as fat). This is deemed in the “real world” as someone becoming less active or sedentary.

        In this way it is possible that fat storage leads to lethargy and overeating.

        You CANNOT say calories in = calories out and accept that as fact, but then refuse to acknowledge that in a biological system that has feedback loops for survival that the reverse is not ALSO true, i.e. the amount of calories used is related to the amount of calories consumed, and the amount of calories that can be used, is also affected by how many are available. If you cannot access the calories, because the excess insulin has caused storage then it is entirely logical that this will result in either lethargy and/or excessive consumption of calories.

        You are basing your entire arguments on what you have been taught, yet simple logic, basic biochemistry, endocrinology and thermodynamics demonstrate that your arguments are lacking in basis in simple facts, and are only supported by your belief that because someone with an academic degree taught you it whilst you obtained the same academic degree they must be true.

        Start using that overeducated brain of yours and apply the scientific method of investigation and query to this stuff and whilst you may find you wasted tens of thousand of dollars on the facts your were taught during your education, at least those tens of thousands of dollars would have amounted to something, by equipping you with you skills and knowledge to challenge the status quo and forge ahead with new lines of thinking and insight. Again, some of the top, scientists, cardiologists, endocrinologists, biochemists and even exercise physiologists in the world are recognising this – go on, back yourself to be ahead of the scientific herd, trust me NO great scientist just accepted what he or she was taught!!!

        1. Please excuse typos – was just belting this long post out… notable errors (there is likely more):

          “I invoke me degrees in…” should be “I invoke my degrees in…” (always dangerous editing “let me” into something else on the fly)

          “If are bodies are…” whoa – one too many are’s and one few on the our’s… Should be “If our bodies are…”

        2. Again, my point is that it is wrong to think that the body is designed to rely solely on protein as a source for glucose (gluconeogenesis). This is the claim that the author of this article is making. My point in response to others is that carbohydrate is not toxic, and that it is important for the body, particularly the brain.

          To reiterate my point, inadequate amounts of carbohydrate intake is not advantageous for the brain. I did not say that an excessive amount of carbohydrate intake is okay. I did not say that our bodies don’t need adequate amounts of fat and protein. Our bodies do not function optimally with zero carbohydrate intake. I think anyone would agree that humans evolved eating vegetables and fruits (plenty of carbohydrate), along with other sources of protein and fat.

          I reveal my education status only to show that I’m not some schmuck posting random stuff, not because I think I’m smarter than everyone.

          I understand the role of liver, gluconeogenesis, and the cycle of proteins to carbohydrate, and carbohydrate to fat, etc. As a biochemist, certainly you understand that protein conversion to carbohydrate in the liver also produces ammonia. If the body were to rely solely on protein in for gluconeogenesis, due to a lack of carbohydrate intake, this would obviously become problematic. Excessive cycling of the urea cycle would cause a protein imbalance.

          I did not say that our bodies are “incapable of utilizing fat as an energy source.” I did not say that our bodies “MUST have vast amounts of carbohydrate in order to function.” I’m saying that our brains need an adequate amount for optimal function.

          Also, the major causes of death of type 2 diabetics are heart attack and stroke. You can get this information from the CDC. Of course, chronic hyperglycemia initiates the disease state. The point is that you will not typically see “hyperglycemia” on the death certificate of a type 2 diabetic.

        3. I will admit that the type 1 diabetic “experiment” isn’t appropriate. It doesn’t address the authors point.

  119. OK, let me walk you through this one step at a time – What CAUSES heart attack and stroke in T2 Diabetics?

    1. Bill,


      I worry about the academic integrity of the current university system if people with masters that are studying doctorates cannot understand the difference between a cause and an effect!!!

      I guess this whole Seth thing proves what we already know – busting the conventional wisdom is going to take a long time, when even the (so called/self professed) best and brightest science graduates are so indoctrinated and brainwashed to the point they abandon all scientific curiosity and leap to the defence of what they have been taught, rather than seeking to understand a bit more about a different point of view.

      I wish I wasn’t travelling, I would have love to have dosed up the references and also written something a little less stream of consciousness.

      However as your next post states, this guy thinks he knows everything already, so no doubt I wasted my time… or perhaps not, perhaps someone with a true scientific mind of curiosity and interest will read it and take a new perspective from it!?

      1. I do believe that a restricted calorie diet is the most healthy choice. My point is that the body does not function optimally in starvation mode, and that constant gluconeogenesis without any carbohydrate intake is not a normal and healthy state for the body.

        1. “I do believe that a restricted calorie diet is the most healthy choice. My point is that the body does not function optimally in starvation mode,”

          Ummm really, restricted calories is good, but starvation is bad!!!

          Make up your mind!

          The author does not say to eat ZERO carbs (look at the information), so you are arguing about nothing… grow up.

          OK, now you must cite your sources!!!

          “constant gluconeogenesis without any carbohydrate intake is not a normal and healthy state for the body.”

          Where is your source for this?

          Explain Inuit populations, or other populations in Africa that do not eat carbs?

          Explain how we as a species survived ice ages?

          Just because it is not what you are used to, does not mean you can make a claim like this!?

          Again I ask, if the lack of carbohydrate is SO BAD for a human body (or that of any mammal), WHY did we evolve with such a WOEFULLY inadequate glycogen storage system???? You MUST be able to explain this.

          Evolution by natural selection MEANS that if this was absolutely necessary, we would have evolved a better glucose storage system – PERIOD.

          We didn’t evolve this system, because it DOES NOT MATTER or do harm to a human body to be in a state without exogenous glucose from carbs.

          We CAN and do have a system for creating glucose in the body, we do not for certain fatty acids (i.e. fats) and certain amino acids (i.e. proteins)… You JUST IGNORE this, because you have ho answer.

          Cite YOUR sources to make such an outrageous claim that living without a carbohydrate intake is not normal or healthy, when the evolution of the entire animal kingdom demonstrates otherwise.

    2. “I think anyone would agree that humans evolved eating vegetables and fruits (plenty of carbohydrate), along with other sources of protein and fat.”


      1) Vegetables are NOT a plentiful sources of carbs.

      2) And unlike your pampered existence, fruits are seasonal. You are applying your 21st century understanding of the food chain to our human evolution.

      Fruits don’t become fruit all year round. So they were limited to when available. Just because you can walk into a Whole Foods and buy fruits at any time of the year does not mean that is how we evolved – seriously – you have a masters and are getting a doctorate?!

      3) The fruits we most commonly ate were berries, we also ate nuts. We lost our ability to climb, so we in essence ceded fruits high in trees to our ape cousins until we worked out tools to get them down. Berries are NOT high in carbs (relatively)

      “If the body were to rely solely on protein in for gluconeogenesis, due to a lack of carbohydrate intake, this would obviously become problematic. Excessive cycling of the urea cycle would cause a protein imbalance”

      What are you doing – just arguing to show how smart you are?! NOT ONCE in any part of this site does the author EVER suggest NO carbohydrates – EVER, so your point is irrelevant (and revisionist).

      The author recommends berries (is not so keen on bananas as they are VERY high in carbs), and does recommend fruit. Mark (sorry over calling him the author), advocates MOSTLY green leafy things as the basis of the dietary recommendations (by the way the Primal Blueprint is MORE than a diet – you wouldn’t know this, because you are just arguing, telling us we are so misinformed, without checking what is actually being recommended – which is worse misinformed, or just uninformed?!)

      “I’m saying that our brains need an adequate amount for optimal function.”


      I don’t have the references with me, but in well designed tests where those on ketogenic diets were compared to those on regular diets the cognitive functions were equal. The only studies where this isn’t these case have a design flaw. If you switch from a carb heavy diet to a low carb diet, then it is a KNOWN fact that it takes up to two weeks for the body to get back into full swing burning fats. So if you do a test where you take high carbers (and that means people that eat pasta, bread and rice) and then switch them to low carb and test them immediately, they will do worse.

      This fact supports the theory that we evolved with very low carbs in our diet.

      If we did have high carbs and each time we ran out (which would have happened often in prehistoric past human life) and it took weeks to get back to optimum, then we would have evolved to not have that lag (because being impaired in this way would put you at risk, and those that switched quickly would have had a survival advantage).

      The fact this lag persists to today means we DID not have high carb diets that then resulted in us having a lag in switching back to low carb. We just were low carb most, if not all the time.

      We then rarely got some carbs, but this did not occur for so long that we needed to “switch back to low carb” and adjust.

      I mean this is SIMPLE deduction using evolutionary theory.

      “Also, the major causes of death of type 2 diabetics are heart attack and stroke. You can get this information from the CDC. Of course, chronic hyperglycemia initiates the disease state. The point is that you will not typically see “hyperglycemia” on the death certificate of a type 2 diabetic.”

      And who said that hyperglycemia is the cause listed on the death certificates of type 2 diabetics?!

      You are being revisionist here… you are trying to weasel out of the fact that you made this stupid statement!

      The previous poster stated:

      “hyperglycemia is one of the major causes of the eventual death of T2 Diabetics”.

      Whilst this is not perfect stated, only someone trying to be a smart arse would try and say that this post was suggesting that hyperglycemia is what is listed in the death certificate.

      There you go again with the use of “higher authority” by calling on the CDC… WHY?

      In my answer I stated:

      “The damage to the vascular system, including the regulation of blood pressure by the kidneys is damaged by CHRONIC hyperglycemia. As a result after YEARS of elevated blood glucose (hyperglycemia) the damage to the vascular system results in heart attacks and strokes.”

      Clearly I am aware that heart attacks and strokes are the listed cause of death, but the cause of the heart attack and strokes is hyperglycemia – FACT, don’t need the CDC, I have worked in the area, and you were being smug in your original post and now are trying to say you were just misunderstood.

  120. No, you know what, never mind. Since you refuse to look up the recent information on the subject, you are not interested in learning. You believe you already know everything. Good luck in your future endeavors.

    1. I don’t think I know everything. I’m saying that I do know what hyperglycemia is and that I don’t need to look it up.

  121. Luke, thanks for taking the time to write all that. I Had to laugh at the “bad diet and no exercise” myth, since I grew most of my own food, ate nothing but whole fruits, vegetables and “healthy grains”, and worked out 4 days a week with a trainer, and ran the other three days. I ate better and exercised more than the average human, but the excess amount of carbs in my diet caused (surprise!) an excess of carbs in my blood! Now, I have cut back the dietary carbs to a metabolically insignificant amount, and (double surprise!) have had 10 years of rock stable BG readings. I am so sure I am going to listen to some guy on the internet who claims to have studied something as opposed to the many practicing cardiologists, PHD biochemists, and long term successful T2 Diabetics. I happen to be working on an advanced degree in Biochemistry and I can already point to the many mistakes in basic assumptions in my text books. I just learn it the way they tell me and wait until I can be the one writing the books and teaching the classes.

    1. A poor diet that includes excessive calorie intake, and no regular exercise, does lead to chronic hyperglycemia type 2 diabetes. Type 2 diabetes is typically reversible with calorie restriction (a balanced diet) and/or exercise.

      I’m trying to put together what you’re saying, and it sounds like you’re saying that eating only fruits, vegetables and grains, and exercising 7 days a week caused blood glucose levels of 700. That obviously doesn’t sound right. Please clarify, or at least tell the whole story.

    2. Haha – gold… let me know when you publish, I’ll buy that book!!!

      However I assume you mean a text for physiology, as in biochemistry texts, all the basic information is already there!!!

      At least when I was studying, they described the pathways etc (without the dogma of fats are bad/carbs are good/proteins are depends on who you ask), then it is clear that the human biochemical pathways (and in fact mammalian biochemical pathways) favour fatty acid utilisation in a great number of situations.

      The hormonal function of insulin is clear, it allows glucose transport into cells and promotes fatty acid biosynthesis from carbs and fatty acid storage in the fat cells. In the absence of insulin this process is reversed. The hormone glucagon (essentially “anti-insulin”) promotes the reverse process (i.e. breakdown of fatty acids for use as energy and the release of fats from fat cells). These are not debatable – these are biochemical FACTS.

      Additionally Glucagon signals the liver release glucose into the blood stream and promotes gluconeogenisis from amino acids. Glucagon is suppressed by the release of insulin.

      The consumption of ANY food releases insulin (and down regulates as a result Glucagon), however the presence of carbohydrates (particularly refined carbs and fructose) result in a significant spike in insulin, and a subsequent drop, which can induce hunger. Fats and proteins are more slowly absorbed, and as a result do not invoke such a large insulin spike. As a result glucagon is able to produce glucose if needed, and with the lower insulin levels fatty acid oxidisation (i.e. fats as fuel) is able to occur.

      Again these are facts of biochemistry.

      Based on these facts of biochemistry the worst meals in terms of weight gain are:

      1) high fat & high carbs. Huge insulin spike, fats shuttled into fat storage AS WELL AS THE carbs converted into fatty acids for further fat storage. Stored fats not available for use (high insulin levels lock it in – and promote insulin resistance too), meaning you feel hungry for calories to make up the shortfall between the amount available from your meal and what you are using, so you EAT more than you would normally to get the SAME amount of available calories for your body to use. Worse still, high insulin spike results in HUGE blood glucose drop (carbs stored as fat and what is left is rapidly used), resulting in low blood glucose, leading to feelings of hunger. With the combination of stored calories and blood glucose drops, even if you manage to ignore your hunger and hot eat, you end up with feelings of lethargy, as you have less energy available, especially when insulin resistance develops due to the excessively high insulin levels, because even if you eat more, your muscles now can’t absorb the energy. High carb and high fat meals are a double whammy!!! Biochemistry facts, don’t need a masters of PhD to work this stuff out

      2) High carb low fat meals (but still high in calories). Pretty much the same as above, except you wont store as MUCH fat (less to directly store), but still some carbs get converted due to high insulin. Same result in less available calories, so need to eat more, similar Blood Glucose crash, so similar feelings of hunger. High insulin levels also result in insulin resistance, with subsequent weight gain, reinforcing insulin resistance and also the lethargy cycle described above.

      3) Just and average mix of all three nutrients. with enough exercise you may avoid weight gain for some time. Likely to result in slow insidious weight gain that creeps up over 5-10 years, eventually tipping the system enough to result in a rapid weight gain and perhaps some pre-diabetic symptoms. You believe the exercise physiologists of the world and cut out some fat from your diet (and end up at point #2 above!!!)

      4) Primal/paleo approach. Mid-level carbs (not low carbs), moderate protein and high/er fat. Moderate insulin response, with possibly glucagon available if needed. Insulin levels are such that fat storage is minimised if at all present, however fat release is not promoted either. Weight is maintained easily. Energy levels are fine, as amount consumed = amount available, and also lower insulin levels and body weight in normal range means little if any insulin resistance.

      5) Primal/low carb. Lower carb level, moderate protein and high fats – only when seeking to lose weight. Very low insulin response. Absence of carbs in diet promotes glucogon release and gluconegenisis. This triggers fatty acid release from fat cells, fatty acid oxidisation and ketones do form. Energy pouring out of fat cells, results in increased available energy, so eating less calories is easier, without hunger, and still meeting calorie expenditure needs. Once you reach your target weight, you up the carbs to kill off ketosis and jump back up to #4 above to maintain weight.

      All of this makes biochemical (and endocrinological) sense. It is consistent with known biochemical pathway and hormonal systems understanding and facts.

      The alternative that you can eat like #2 and lose weight is bullshit… only way is to cut calories or up exercise, which most people can’t maintain due to resulting hunger and lack of available energy (insulin levels still promoting storage if possible) – granted excessive deficits will result in fat being released – but inefficient and sadistic way to lose weight compared to #5/#4 which are biochemically and hormonally the easiest way to do it.

      Of course those that build their living on people needing to be cajoled/hounded/berated by a personal trainer or dietician has a significant conflict of interest in accepting anything but approach #2, as it is the approach that maximises the need for their services!!!

      That is why I have left pharmaceuticals. After discovering MDA, Primal Blueprint and all the other information I have researched in scientific papers and textbooks since, I realised that that industry, whilst it did not create this myth of how to lose weight, it is profiting from this awful error in human understanding. So now I spend my time ripping apart the flawed logic in those still clinging to conventional wisdom… of course working in pharmaceuticals I was trained on how to promote conventional wisdom and confuse others when they noticed it’s flaws (Seth used the most common used by pharma – the “higher authority/academic backing” card)… with that knowledge I find it easy to pick the blatant holes in their arguments and point them out for the fallacies that they are… Hopefully I can use that to help a few people see that conventional wisdom, and hence medicine and health authorities have bet the collective health of the human race on a flawed premise about human metabolism…



      1. I’m in agreement with this.

        What blatant holes are there in my argument? The author of this article insists that we don’t need to consume carbohydrate because the liver creates all the carbohydrate we need. Yes, the liver can produce carbohydrate, but overall this is a misunderstanding. The author has taken a know piece of biochemistry and has spun it out of control.

        I list my academic achievements to make the point that I have formal education.

        For the record, I’m not a personal trainer, or work in any industry, or cling to any “conventional wisdom.” I’m an extreme opposite. The incorrect “conventional wisdom” out there appears to be that diet and metabolism must be incredibly complicated, and that there’s some secret to eating well and losing weight. For example, the author of this article suggests that we all need to completely do away with carbohydrates because he/she heard about gluconeogenesis in the liver. That’s great if one wants to lose weight, but it’s not sustainable.

        Again, what you typed about the body’s biochemistry and physiology is basically correct. But I’m not sure what your point is and how it relates to the author’s article.

        1. Again – you have decided to argue, without checking your facts.

          1) The author (Mark) actually advocates eating is easy, his easy just limits carbs by excluding grains. You are hung up that your easy is the right easy.

          2) Repeated studies and empirical evidence show that restricted calorie diets are NOT easy and as a result FAIL, again and again and again.

          3) The Author (Mark) NEVER, not ONCE stated to eat no carbs… you are misleading stating this:

          Let me copy the text here, if it is TOO hard for you to scroll to the top of the page and read it:

          “So How Much Glucose Do You Really Need?

          Much less than most people assume. At any one time, the total amount of glucose dissolved in the bloodstream of a healthy non-diabetic is equivalent to only a teaspoon (maybe 5 grams). Much more than that is toxic; much less than that and you pass out. That’s not much range for a so-called “preferred” fuel, is it? Several studies have shown that under normal low MET conditions (at rest or low-to mid- levels of activity such as walking and easy work) the body only needs about 5 grams of glucose an hour. And that’s for people who aren’t yet fat-adapted or keto-adapted. The brain is the major consumer of glucose, needing maybe 120 grams a day in people who aren’t yet on a low carb eating program. Low carb eating reduces the brain’s glucose requirements considerably, and those who are very low carb (VLC) and keto-adapted may only require about 30 grams of glucose per day to fuel the brain (and little-to-none to fuel the muscles at <75% max efforts). Twenty of those grams can come from glycerol (a byproduct of fat metabolism) and the balance from gluconeogenesis in the liver (which can actually make up to a whopping 150 grams a day if you haven’t metabolically damaged it with NAFLD through fructose overdosing). Bottom line, unless you are a physical laborer or are training (exercising) hard on a daily basis, once you become fat-adapted, you probably don’t ever need to consume more than 150 grams of dietary carbs – and you can probably thrive on far less. Many PBers do very well (including working out) on 30-70 grams a day."

          Where is the ZERO?

          Mark even includes a GRAPH (pictures are easy aren't they?) that shows that he has three zones with 100-150 being effortless weight maintenance, 50-100 effortless weight loss and <50 Ketosis / intermittent fasting…

          "the author of this article suggests that we all need to completely do away with carbohydrates because he/she heard about gluconeogenesis in the liver. That’s great if one wants to lose weight, but it’s not sustainable."

          I call BS…

          This guy hasn't just heard about gluconeogenisis in the liver… I'm not going to bother to do your intellectual works for your, go and read about him AND HIS qualifications, seeing that is all that matters to you!!!

          Secondly ALL the information he gives states that the lower levels are for weight loss, and that the sustainable level is between 100-150.

          This is in EXCESS of the daily requirements of the human brain, and is above ketosis – did you EVEN READ this article before deciding to attack it from your pseudo-intellectual ivory tower?

          "A poor diet that includes excessive calorie intake, and no regular exercise, does lead to chronic hyperglycemia type 2 diabetes."

          True – but what you have now done is state a fact, and inferred that means everything else you have said is therefore right.

          You have YET to identify (let alone cite) a substantial reason that this approach that Mark writes is not a healthy diet. Your reasons are based on FALSE assumptions of what he has said. You even assume he means no fruit or veg, yet if you read his recommendations, you would see that veg are the basis of his food pyramid and many fruits (not all) are part of the recommendations too. He also has an 80% rule, which is follow it at least 80% of the time and don't obsess over things if you stray, as he firmly believes that people make it all too complicated.

          "Type 2 diabetes is typically reversible with calorie restriction (a balanced diet) and/or exercise"

          For as long as the calorie restriction lasts. A ketogenic diet has repeatedly been shown to be the most effective at reversing type 2 diabetes. There are papers galore on this, and I have also witnessed it with living breathing type 2 diabetics.

          The low fat high carb approach (even the whole low GI thing) is torturous for the reasons I outlined in the post that described the diet approaches. You ask them to exercise, and yet you give them a diet that does not allow them to maximise energy expenditure.

          A Ketogenic diet opens the fats cells to releasing fats – this is a biological/biochemical/endocrinological FACT… it is backed up by the reports from both diabetics and non-diabetics that adopt these diets that they feel like they are almost bursting with energy… well this is almost quite literally true… the now released fatty acids from their fat cells provide so much energy to them, that they can reduce caloric intake without feeling hungry (the body doesn't send hunger signals when it is bathing in energy) and they also have enough energy and reduced lethargy to exercise.

          You AGAIN are assuming that the equation is one way… I can't explain it any easier… go read up about it.

          The storage of energy from the diet as fat (due to hugh insulin) traps this energy, making it unavailable for use, and hence increases appetite or reduces energy expenditure. Either way the result is less movement with weight gain, or more eating with even more weight gain, most often BOTH.

          You then observe this and state it is the eating and reduced movement that causes fat storage, instead of realising that it can also be the fat storage that causes increased eating and reduced movement – IT WORKS BOTH WAYS.

          Yes it is true some people eat too much, but again, biochemically, eating carbs increases your chances of an insulin spike and then crash, which makes you more likely to feel hunger again. Again this is born out in studies and from real life experience.

          Eat a pasta meal for and you are SURE to be hungry when you wake up (sometime even before bed).

          Eat a protein and fat meal and you can even skip the next meal if you want. Repeated studies show satiety with proteins and fats FAR outstrips carbs, especially calorie for calorie.

          So whilst this is true, it doesn't mean it is the ONLY truth.

          "Type 2 diabetes is typically reversible with calorie restriction (a balanced diet) and/or exercise"

          It is also reversible with a reduction of carbs by eliminating grains (still eating veg and lower carb fruits) and/or exercise. And it doesn't result in hunger, and the foods are generally more enjoyable to eat.

          This I have witnessed with my own eyes. The second approach which is diets #4 and #5 (in my previous post) are much better than #3 – which is what you advocate.

          You have NEVER tried it, let alone understand it, yet you reject it.

          Spend some time reading through this site – you will see this is NOT a no carb site.

          The point is we don't need to eat as many carbs as is typically done (even without going into ketosis) – and this is backed up by science.

      2. Actually, after reading and thinking about this article more, I’m in agreement. And yes, I mistakenly jumped to some conclusions. He doesn’t say no carbs.

        However, I still have a problem with some of the author’s comments, which are reasons why I first posted:

        “… and the brain can run just fine (maybe even optimally) on a blend of ketones and minimal glucose. . . Entire civilizations have existed for ages on what is practically a zero-carb diet.”

        I don’t think it’s correct, and I would like to find sources that back this up.

        1. Seth,

          I have to acknowledge 2 things:

          1) You are a better man than most. May people argue their position, and wont budge, no matter what the evidence. Even more so for people that post on blogs etc… Have to say well done mate (and please do not take that as patronising, I sincerely mean it).

          2) I was a bit of a dick last night (well last night as far as the time zone I am in). I have been travelling for work, and was jet lagged, and clearly in a foul mood.

          This does not excuse some of the things I said in debating you, in particular the amount of ad hominem statements I made… poor form on my part and intellectually weak…. Argue the points/topic, don’t attack the person, I apologise for my snide remarks – no excuse.

          Regarding your remaining doubts about the following statement:

          “… and the brain can run just fine (maybe even optimally) on a blend of ketones and minimal glucose. . . Entire civilizations have existed for ages on what is practically a zero-carb diet.”

          Again I do not have references on hand, however a few things:

          1) Civilisations have existed for ages on what is practically a zero-carb diet. Inuits, various tribes, and significant portion of our entire species during the ice ages. This is documented.

          2) “and the brain can run just fine (maybe even optimally) on a blend of ketones and minimal glucose…”

          Again, there are sources to back that the brain can run just fine on a blend of ketones and minimal glucose… the key here being the use of the word minimal… minimal is definitely above zero, probably around 80-100g of carbs per day, but not much more than around 150g carbs per day for MOST people (naturally exceptions are always present). This is significantly less than what the typical diet would consume, especially if you eat wheat, corn or rice products. I would encourage you to do a search using the search function on this site. Mark will likely have a post specifically on carbs, and he will cite references many times. This post was a summary of a number of different concepts he has written about over many years.

          This leaves “(maybe even optimally)”… This is Mark’s view. He does not the brain DOES run optimally, he states it MAY run optimally. MAY is the universal qualifier. Whenever you see it, you can safely assume there is no specific evidence to be cited. It does not mean it doesn’t exist, it just means it isn’t being used.

          This is a problem when you read/hear/watch most news bulletins these days, to avoid doing REAL journalistic investigation, they just say “may”, “perhaps”, “suspected”… all these words allow you to say what ever you want, without a shred of evidence.

          “We may all die tomorrow”… UNLIKELY, but logically true, as we MAY all die tomorrow, no way of knowing.

          “X X may run for President”… again – 100% true, no matter how likely.

          If I wasn’t travelling I’d take the time to find some evidence, as I am certain I have read it somewhere.

          You may ask, but you defend this dietary approach, how come you are unsure?

          Simple – For all the biochemical and evolutionary reasons I have stated, and results I have witnessed with my own eyes, I know the elimination of carbs from grains and increased consumption of fats is NOT the health issue many state.

          I also know you can function on reduced carb consumption, both physically and mentally.

          To me, whether you perform better, is irrelevant. Likewise, even if it isn’t perfect, I know it works.

          However finally, I am a fanatic when it comes to the power of evolutionary pressures, and quite simply when you apply evolution to the problem, the fact remains, that as a species we MUST do at least as well, if not better with very low carb consumption, because until we learnt how to mill wheat, rice and corn and then COOK it (which was only ~ 10,000 years ago), the VAST majority of the human race just DID NOT HAVE access to that many carbs and so without having a choice, lived a VERY low carb diet. Add the selection pressures of an ice age (when the ability to survive on near zero carbs would have been selected for) and also the “thought experiment” I described about how the switching from high to low carb results in a lag in switching back to a low carb system SUPPORTS the fact we evolved not having ready access to lots of carbs (otherwise that lag would have been selected out) then I just cannot see how we CANNOT thrive on a low carb diet – evolution has selected us for that, and biochemistry provides all the proof to show fat is the preferred fuel source.

          And finally (there is always a finally) – our vast ability to store fat (actually I missed this in Mark’s post above, I independently came to the same conclusion as he has), and PALTRY ability to store carbs. If carbs are SO important for optimal function we would have evolved to preferentially store them – NOT fat.

          Anyway – all I can suggest is you explore this site more. As I said search for certain topics for more in depth posts (and perhaps use the menu system on the top to find topics).

          All the best with the exploration…

        2. Regarding your statement, “If carbs are SO important for optimal function we would have evolved to preferentially store them – NOT fat.”

          I can understand why one would believe this to be evidence for preferential use of fat by the body. However, it’s misleading. The reason animals have evolved to store calories in the form of fat is because adipose (fat) contains very little water compared to stores of glucose (glycogen). For every gram of glycogen, there’s something on the order of 3-4 grams of water with it. We evolved to store energy as fat simply because it’s a very efficient calorie storage mechanism. This mechanism allows animals to not have to carry heavy stores of energy. And it follows that there’s a relatively large amount of energy that is released when these long hydrocarbon chains are oxidized. I don’t think it’s accurate to say that energy is stored as fat because the body prefers to utilize fat. I think it would be more accurate to say that the body utilizes relatively large amounts of fat at REST because the demands for energy are less (creating time for the enzymatic events in beta oxidation, the krebs cycle, and oxidative phosphorylation). Although large amounts of energy are released, due to the efficient storage of this energy, it’s sluggish compared to glycolysis. I just can’t make an argument that the body prefers fat, mainly because the brain does not utilize fat. Most physiological processes in the body (e.g., cardiovascular, metabolic, etc.) function so as to serve the brain first.

        3. So far, the data doesn’t support this.

          Br J Nutr. 2010 Dec;104(11):1666-87. Epub 2010 Sep 23.

          Estimated macronutrient and fatty acid intakes from an East African Paleolithic diet.


          “We found (range of medians in en%) intakes of moderate-to-high protein (25-29), moderate-to-high fat (30-39) and moderate carbohydrates (39-40).”

        4. Furthermore, why would the contents of human milk (1.1% protein, 4.2% fat, 7.0% lactose) be so different?

        5. I agree that our primitive ancestors probably consumed less carbohydrate than modern Americans, for example. And I also agree that our primitive ancestors, and modern humans, prefer fats over carbohydrate (I also agree that a ketogenic diet my be healthy in some respects for the brain, based on some interesting research articles I read today). However, our best estimates of a primitive diet does not reflect fat intake exceeding carbohydrate intake. If carbohydrate were limited to what is suggested here, and according to what you say (“minimal is definitely above zero, probably around 80-100g of carbs per day, but not much more than around 150g carbs per day for MOST people”) the rest of the daily requirements just for resting metabolic function (1600 kcal, for example) would have to be made up in large proportion in fat and protein. 100 grams of carbohydrate is only 400 kcal. Healthy, daily activity would about double the required calorie intake. This paradigm (100-150 grams carbo) seems to be okay just to meet resting metabolic needs (or to lose weight), but remember that our primitive ancestors were also distance runners! There’s has to be room for calorie intake for physical activity.

          The research article below suggests that protein intake often takes place of carbohydrate intake in hunter-gather diets, but that the proportion of fat or protein intake probably doesn’t exceed carbohydrate intake.

          Am J Clin Nutr. 2000 Mar;71(3):682-92.


          Plant-animal subsistence ratios and macronutrient energy estimations in worldwide hunter-gatherer diets.

          “This high reliance on animal-based foods coupled with the relatively low carbohydrate content of wild plant foods produces universally characteristic macronutrient consumption ratios in which protein is elevated (19-35% of energy) at the expense of carbohydrates (22-40% of energy).”

        6. Okay, I’m more in agreement now, considering the research article below:

          Am J Clin Nutr. 2000 Mar;71(3):682-92.

          Plant-animal subsistence ratios and macronutrient energy estimations in worldwide hunter-gatherer diets.


          “Our macronutrient projections for worldwide hunter-gatherer diets indicate that these diets would be extremely high in protein (19–35% of energy) and low in carbohydrate (22–40% of energy) by normal Western standards, whereas the fat intake would be comparable or higher (28–58% of energy) than values currently consumed in modern, industrialized societies.”

      3. “However I assume you mean a text for physiology, as in biochemistry texts, all the basic information is already there!!!”

        All the information is there, and then they simply ignore that information to express assumptions which are contra-indicated by their own data. (Paraphrase) “Insulin controls the level of blood glucose by opening the transport proteins which leads to the glucose binding to fatty acids which cannot leave unless glucagon releases the glucose from the cell. But obesity is actually caused by eating a poor diet and not exercising enough.” It’s like a disconnect between their information and their ability to think, probably caused by having heard the lie so often. I have marked this kind of false interpretation of the data in my Physiology books, my basic biology book, and even in both psychology books so far. It was presented without the biochemical info in my last math book and I know I am going to run into it in my “Human Ecology” class. I even had to sit through my language instructor’s lecture about it, as if it had anything to do with APA citation guidlines.

        The facts are all there (as in Mark’s article), but many people simply cannot see them because their assumptions are smack in the way.

        1. Hey Bill,

          Yeah you are right… I likely have forgotten the finer details like the throw away comments… I will admit it was some time ago I was at Uni.

          Good luck with the studies and as I said, I look forward to reading Biochemistry Essentials by B. DeWitt!!! 🙂

  122. JAMA. 2003 Apr 9;289(14):1837-50.


    Efficacy and safety of low-carbohydrate diets: a systematic review.


    We performed MEDLINE and bibliographic searches for English-language studies published between January 1, 1966, and February 15, 2003, with key words such as low carbohydrate, ketogenic, and diet.


    There is insufficient evidence to make recommendations for or against the use of low-carbohydrate diets, particularly among participants older than age 50 years, for use longer than 90 days, or for diets of 20 g/d or less of carbohydrates. Among the published studies, participant weight loss while using low-carbohydrate diets was principally associated with decreased caloric intake and increased diet duration but not with reduced carbohydrate content.

    1. “There is insufficient evidence to make recommendations for or against the use of low-carbohydrate diets”

      Yup. One of the fundamental laws of real science is that if you refuse to ask the right questions, the answers you get are meaningless. Even if they are correct. What passes for science in the field of nutrition is mostly superstition. Low-carb diets are simply NOT STUDIED, or if they are, it is invariably using partially hydrogenated corn oil as the main source of fat (e.g. https://www.ncbi.nlm.nih.gov/pubmed/21321316).

      OTOH, I have yet to see a study in which dietary carbohydrate was reduced, even slightly, that did not produce health improvements. Although said improvements are *ALWAYS* attributed to something other than the carbohydrate reduction.

    2. OK Seth,

      Lot’s to consider from your posts:


      “I can understand why one would believe this to be evidence for preferential use of fat by the body. However, it’s misleading. The reason animals have evolved to store calories in the form of fat is because adipose (fat) contains very little water compared to stores of glucose (glycogen). For every gram of glycogen, there’s something on the order of 3-4 grams of water with it. We evolved to store energy as fat simply because it’s a very efficient calorie storage mechanism….I don’t think it’s accurate to say that energy is stored as fat because the body prefers to utilize fat….”

      I was kinda hoping you would take this approach to defend the lack of glycogen storage due to water storage requirements AND energy efficiency. This observation on your part allows evolutionary pressures (my thing remember) to come into their own.

      AGREED – you cannot conclusively state that “that energy is stored as fat because the body prefers to utilize fat”, however that does not mean you cannot hypothesise the following:

      What you have just stated is that the organism (i.e. animals including humans) prefers fat storage due to the fact that carbs require significantly more water to be stored with them AND fat is a more energy dense nutrient.

      So, why do you assume that evolution works in only ONE direction? By the VERY fact that carb storage is inefficient and cumbersome due to water storage needs, this would provide SELECTION pressures for the organism (ALL of them) to FAVOUR fatty acid metabolism.

      Due to the fact that you SO ELOQUENTLY and emphatically NAIL the final nail in the coffin for carbs as an energy source – i.e. they SUCK as an energy for storage for an living organism, then the organisms that developed EFFICIENT metabolisms for the energy source that IS EASILY stored would prosper when food was scarce etc, which happened often before we humans worked out how to used OIL energy to counter nature (fertilisers, pesticides and intensive farming ALL rely on oil energy – without it, we cannot feed the population)

      You have just provided the VERY reason that fats are a preferred energy source, because over MILLIONS of years of evolution (even before we were humans) we (and all other animals) evolved with a selection pressure for efficient use of the energy source that is most EASILY stored – FATS

      NOW in anticipation of your (and probably others reading this) chomping at the bit for all the “VEGETARIAN” animals, I have the trump card for you.

      Let me quote from a great website I found on the subject (written by a PhD no less!!!):

      “No mammal — not even the herbivores — has developed an enzyme that will digest vegetable fibre. This is why we tend to discount it when calculating our calorie intakes. However, while mammals have not developed an enzyme that will digest fibre, there are lots of micro-organisms and bacteria that can the job for them. The herbivores employ billions of these bacteria.”

      “In a herbivore such as the gorilla, the caecum and colon harbour huge colonies of bacteria which ferment carbohydrates, particularly fibre, and use it to produce short chain fatty acids (SCFA) — principally acetic, proprionic and butyric acids. These are then absorbed into the body to be used as a source of energy.

      If we look at the gorilla’s diet, we now see that the authors of the study into the western lowland gorilla’s diet find that the fibre provides some 1.5 kcals of energy per gram of fibre, in the form of SCFA. As the fibre averages about three-fourths of the gorilla’s diet, this energy forms a highly significant proportion of the gorilla’s total energy intake.

      These SCFAs must be added to the fats already present in the gorilla’s diet, which gives us the following proportions:

      Overall energy
      (kcal) per 100g %age
      Protein 47.1 24.3%
      Available carbs 30.6 15.8%
      Fat 4.9 2.5%
      SCFA from fibre 111.0 57.7%

      This gives totals of:

      protein = 24.3%
      carbs = 15.8%
      fats = 59.8%

      In other words, although the western lowland gorilla’s diet, exclusively of leaves, looks like a very low-fat, carbohydrate-rich diet, it is actually a high-fat, moderate-protein, low-carb diet.”


      1. Popovich DG, et al. The Western Lowland Gorilla Diet Has Implications for the Health of Humans and Other Hominoids. J Nutr 1997; 127: 2000-2005.

      Ruminants do the same.

      Let that sink in… The fibre is fermented by intestinal bacteria to produce short chain FATTY acids (i.e. FATS). The kicker is these SCFA are also almost ALL saturated!!!

      This is found at the following web site:


      There are references for the article (about 8 or so I believe)

      Even those herbivores are running on fats (they just need a symbiotic relationship with some bacteria to make the fats from the otherwise nutritionally poor fibrous plants).

      Secondly you write:

      “I just can’t make an argument that the body prefers fat, mainly because the brain does not utilize fat. Most physiological processes in the body (e.g., cardiovascular, metabolic, etc.) function so as to serve the brain first.”

      This is not entirely true. The brain DOES utilise (sorry I’m Australian – I spell English, not American) fats, via the utilisation of Ketones… Sure it does not use a fatty acid, but the conversion of fats into ketones provides the brain with an energy source… and quite an effective one at that.

      However yet again you are making an ALL or NOTHING argument…WHY?! Why can’t the body prefer fats in general… again to remind you no one is saying eat NO CARBS.

      And even if you did, apart from ketone bodies, with sufficient protein in the diet (over what is needed to prevent use of muscle tissue) the utilisation of gluconeogenisis would provide enough glucose for the brain, and to your point about acetone… if you needed it constantly, with NO carbs, but consuming over 50, 100 or up to 150 in carbs a day would easily supply enough (approx 120) for your brain either alone or with some gluconeogenisis.

      I just do not get why you fall back into the assumption of NO carbs is what is being proposed? The ENTIRE premise here is that fats are a GREAT energy source for most of the body, and what carbs you do need for your brain is so low as to NOT require the consumption of carbs by eating grains of any sort.

      Also, the fact we thrived and survived as a species PRIOR to the consumption of grains, just PROVES a diet minimal in carbs is absolutely FINE, if not preferential.


      ““We found (range of medians in en%) intakes of moderate-to-high protein (25-29), moderate-to-high fat (30-39) and moderate carbohydrates (39-40).””

      Nice citation. A few things:

      1) I’m wary of these studies with HUGE ranges, especially if conducted be recent observations… unfortunately (for them) no tribe on this planet hasn’t had some external influence from our “science” and “knowledge”… Even the authors state: “The objective of the present study was to reconstruct multiple Paleolithic diets to estimate the ranges of nutrient intakes upon which humanity evolved.” Reconstruct is not observe.

      2) You left out a conclusion that was important enough to be in the abstract “We conclude that compared with Western diets, Paleolithic diets contained consistently higher protein and LCP, and lower LA. These are likely to contribute to the known beneficial effects of Paleolithic-like diets, e.g. through increased satiety/satiation. Disparities between Paleolithic, contemporary and recommended intakes might be important factors underlying the aetiology of common Western diseases. Data on Paleolithic diets and lifestyle, rather than the investigation of single nutrients, might be useful for the rational design of clinical trials”

      I love this, all people like, myself, Mark (and others like us) want is for the DOGMA of low fat is good, high fat is bad to be at least TESTED scientifically. As your initial reaction has demonstrated, the prejudice AGAINST this dietary approach is SO vehement that opponents even MISS crucial facts (like it isn’t NO CARB) and go on the attack. Again without any evidence, just feelings, they cannot get around the fact that the reason you see the brain running on glucose only, is because you have NEVER let your brain run without what is in evolutionary terms a VERY high level of blood glucose.

      I was going to ignore your human milk factoid, as it’s relevance to overall human nutrition is obvious. What human milk provides a human infant is hardly proof of anything other than what a human breast is capable of producing!!! Additionally, this nutrient analysis was almost CERTAINLY conducted on mothers that eat MOSTLY carbs due to the current nutritional DOGMA! Perhaps if they were fed a diet that was richer in fats and protein they milk would be nutritionally different?! We know that milks of ALL animals are a product of the food eaten by the animal producing them (hence the issue with drug consumption during breast feeding – almost ALL drugs get into breast milk)…

      However in the end your factoid provides an answer “1.1% protein, 4.2% fat, 7.0% lactose” SO YES the % of carbs is higher… but CALCULATE the energy provided by each nutrient then you get:

      Protein – 6.27% of the energy
      Carbs – 39.89% of the energy


      Fats – 53.85% of the energy

      Again, us pro fat anti carbers are not being as basic as saying if you eat 20 gms of carbs you need to eat at least 21 gms of fats – we are saying that the MAJORITY of your dietary energy should came from fats!!!

      And this leads to the next posts you had about nutrient profiles, but first:

      “(I also agree that a ketogenic diet my be healthy in some respects for the brain, based on some interesting research articles I read today).”

      WOW – amazing (and not unexpected from me)… care to share the citation for this article (like you have for others), so that other skeptics can read for themselves and perhaps have their own epiphany!? Once again, I have to say you are better than most, for being so open to finding out more… Perhaps all this typing on my part was worth it if you even take that nugget of “new” (it isn’t new) information to counter your indoctrination… sorry I mean education by the “academics” in nutrition and physiology.

      Anyway onwards:

      “the rest of the daily requirements just for resting metabolic function (1600 kcal, for example) would have to be made up in large proportion in fat and protein. 100 grams of carbohydrate is only 400 kcal. Healthy, daily activity would about double the required calorie intake. This paradigm (100-150 grams carbo) seems to be okay just to meet resting metabolic needs (or to lose weight), but remember that our primitive ancestors were also distance runners! There’s has to be room for calorie intake for physical activity.”

      Again a few things:

      1) True 100gms is only 400 kcals (and 150gms (Mark’s suggested upper limit) is 600 kcals). However consider how the primitive man would get even 100 gms of carbs. You have already acknowledged that primitive humans did not eat wheat, rice or corn (we couldn’t as they are toxic until processed and then cooked). They mostly ate leafy plants and fruits… I trust you still agree.

      Well lets just do the math as they say.

      You can look this up yourself, but the carb content per 100gms for almost ALL leafy plants ranges between 1g – about 5gms, with an average of 3gms (I haven’t found higher, in checking spinach, lettuce, cucumber (technically the fruit), celery, etc but there may be). Let’s be generous and say that for some reason plants have LESS carbs than they had in the past (unlikely as humans have actively SELECTED for increased sweetness in ALL domesticated plants).. and even add 50% to the TOP figure that so we say (artificially mind you) that ALL vegetable matter that humans eat has about 7.5 gms of carbs per 100gms (i.e. 7.5%). And let’s assume that when it isn’t season for fruit that you can only get carbs from vegetable matter – fair assumption I believe?

      So to get 100gms of carbs (JUST 400 kcals as you point out), you would have to eat 100/7.5% = 1333.33 gms – or 1.33 KILOGRAMS (2.93 POUNDS) of vegetables!!!

      Mind you this would be RAW until we were able to cook!

      For 150gms (600kcals) = 2kgs (4.4 lbs) I call BULLSHIT!!! There is no way our primitive ancestors were chewing 2kg/4.4lbs of raw vegetables every day… what’s worse if we take the ACTUAL average 3% carbs the figures are mind blowing, with 5kgs/11lbs for a measly 150gms of carbohydrate!!!! NO WAY, they would spend all day eating… let alone the rest squatting to excrete all the undigestible fibre.

      Now let’s say they did have fruit during the seasons. And let’s take bananas, because they are some of the HIGHEST % carbs of any fruit.

      A banana has 22.8 gms of carbs per 100 gms – or 22.8% (data from fitday.com) Now taking this as the % carbs for ancient man (which it WASN’T bananas are THE food that has consistently been artificially selected by man to add more sweetness, wild bananas are borderline sweet – but i’ll concede it for this comparison, as I cannot know what the ancient carb composition of bananas was, even if I’m near certain it was less) and then doing the same calculation:

      150 gms (600 kcals) of carbs would require 150/22.8% = 657.89 gms (1.45lbs) of banana. According to fitday.com that roughly equates to nearly 4.5 “EXTRA large (9″ or longer)” bananas!!! There is NO way we were walking around finding that many LARGE bananas each and EVERY day – let ALONE more than that.

      2) “remember that our primitive ancestors were also distance runners! There’s has to be room for calorie intake for physical activity”

      I am confident about this (as I have done my own research into this subject) and I even contributed to one of Mark’s posts last year, after which he asked me for the reference, and then wrote his own piece summarising the data. The original post Mark wrote is here:


      My comments (as Luke in Oz (Oz being Australia)) pointed out research by Dr. Daniel Lieberman. It also included the excellent youtube link that shows that we walk/jogged/sprinted/walked when we hunted (not an all out run):


      On that tip about the Lieberman research Mark looked into it and wrote this post:


      Between both those you will see we were NOT the long distance runners that some want us to believe we are. We mostly walked and tracked, with some jogging and sprinting as well.

      ALSO – not EVERYONE in the tribe hunted (although an interesting factoid is that the females also hunted at times). The hunting party was a select group (no doubt chosen for their skills), and as the victors of the hunt, no doubt go to choose the select animal parts to eat. aLso interesting is that it has been shown that hunter-gatherer tribes that have dogs to assist with the hunt or in their camps do NOT feed the dogs the organs, offal and fatty cuts, they eat these preferentially (due to nutritional value) and throw the dogs the LEAN cuts of meat.

      So these members of the tribe definitely had high energy expenditure on days of the hunt and were fed accordingly with PROTEIN and FATS.

      However it is well documented they did NOT hunt every day. After a long hunt like the one in the video they would REST for at least a day (if not more). Additionally many studies have demonstrated that hunter gatherer cultures were NOT in constant search for food and that they had significant leisure time, especially compared to us rat-race modern humans.

      Again let’s do some maths:

      25yo – 5’11” (180cm) male, weighing about 158.7lbs (72kgs) (BMI of 22.2 – which would be typical for a hunter-gatherer, I trust you agree). I picked 25, as it is a fact that hunting and tracking is NOT an easy skill, and the lead hunters were at least this age if not older (the Lieberman study shows the age was about 35).

      Basal metabolic rate = 1789 kcals

      Based on the data from Lieberman of average of about 6km/h (~4mph) for about 4 hours average (which is about right, as the typical distance was 35kms (~22 miles), then from caloriesperhour.com I calculate the energy expenditure as 2,885 kcals

      Meaning that day the expended ~ 4674 kcals – massive huh!?

      Yet, next few days they rest (one kudu or wilder beast yields ~ 120kgs (265lbs) of edible mass – so even for a tribe of 20 that provides 6kgs (13lbs) of meat per person – which is enough for DAYS without another hunt (humans learnt to dry meat for preservation) very early), basically lounge around to recover, so lets say compared to BMR, they burn ~2,200 kcals.

      Although without refrigeration they tended to FEAST up big on the meat and fat from the hunt on the night of the hunt and morning after the hunt and then just eat the gathered nuts, seeds, leafy plants and fruits in the days between. They also could fast for some time if needed.

      Anyway lets say one day hunt then 3 days off, total energy over 4 days is 2819 kcals average per day.

      With 6kgs of meat and nuts and seeds and leafy vegetables, this is not hard to fulfil. Also note that non-hunters needed far less, as they didn’t have that spike.

      Now let’s say from the average of 2800 kcals they did consume half of their carbs from vegetables, and the other half from bananas (which would be a rare luxury – but hey I’ll give it to you, EVEN at the artificially HIGH 5 carbs per 100 gms of 7.5%). To JUST meet your requirement of at LESST 150gm of carbs per days suggests:

      600kcals from the carbs in leafy stuff and fruits (1kg leafy stuff AND 2 bananas EVERY day)

      That leaves 2200 kcals

      Lets say a typical human just cannot eat more than about 200gms of protein a day without feeling stupidly full (anyone that tries to eat that much protein a day usually can’t because the ability of protein to make you feel full means they just can’t shove any more in their mouths!!)

      Assuming ~25% protein per 100gms (typical for most meats that are not LEAN), then this means they eat about 800gms of meat to get another 800kcals

      Leaving 1400 kcals for fats… fats are the ONLY way they could get the rest of their energy.

      At 9kcals per gram, they would need to consume about 156 gms of fats (~1404 kcals) to get to the daily requirement.

      THEY HAVE TO EAT fats (from the animal, nuts, seeds – wherever), because if the even ate JUST half that amount of fat to give only 700 kcals per day from fats, they then need to make up the other 700kcals from carbs or protein.

      With both being 4kcals per g – that means another 700/4 = 175 gms of carbs or protein or a combination of both. Lets split it down the middle at 87.5gms for carbs and 87.5 for protein.

      Thats another ~600gms (1.3lbs) of leafy stuff PLUS ANOTHER banana to make up the 87.5 gms for carbs and another 175 gms of meat… REALLY!?

      If you want to argue their energy expenditure was higher, then you just make it even HARDER for carbs to be the energy source!!!

      The most efficient way for ancient humans to get their energy requirements for each day was to eat FATS – PERIOD. Without grains (that give ~ 50-80% per 100 gms carbs) at their disposal, then the only way to get all that energy, without spending your WHOLE day chewing and crapping was to eat FATS.

      If you look at the available carbs in the foods they could get, the only choice was to eat more fat, otherwise they would starve. There is no way they ate kilograms of green stuff, and so many bananas (when if at all they were available)… without grains they HAD to eat fats and protein, and this is why the human body MUST run fine on fats and protein with a few carbs.

      Now for your quote from a paper:

      ““Our macronutrient projections for worldwide hunter-gatherer diets indicate that these diets would be extremely high in protein (19–35% of energy) and low in carbohydrate (22–40% of energy) by normal Western standards, whereas the fat intake would be comparable or higher (28–58% of energy) than values currently consumed in modern, industrialized societies.””

      1) This looks like observations of current hunter-gather tribes. These tribes have cooking, so they can now eat tubers and more starchy vegetables.

      Now I know we can cook, but for at least 75% of the existence of homo sapiens we did not have cooking, so our biochemical pathways are skewed towards not eating starchy vegetables.

      Additionally even when we did learn to cook, we only started FARMING about 10,000 tears ago… prior to that finding a tuber or starchy vegetable was not as easy as grabbing a bag of spuds from the grocer!!! So again, whilst they no doubt ate and very much enjoyed those bags of carbs when they found them, you could not assume they ate these regularly, let alone every day!!!

      2) By the way, taking the low end of 22% carbs (come one I have given you so many overestimates above), then 600 kcals, if 22% of daily intake = a total intake of ~2730 kcals per day… up near where the hunters above would need… and WAY lower than the 200-300 gns of carbs in the western diet (300gms of carbs with a 50% – 80% carb content per 100 gms is NOT a lot of rice, pasta, bread, corn etc, it is near IMPOSSIBLE to get to eating leafy vegetables and some fruit (unless you make that fruit a juice)


      We performed MEDLINE and bibliographic searches for English-language studies published between January 1, 1966, and February 15, 2003, with key words such as low carbohydrate, ketogenic, and diet.


      There is insufficient evidence to make recommendations for or against the use of low-carbohydrate diets, particularly among participants older than age 50 years, for use longer than 90 days, or for diets of 20 g/d or less of carbohydrates. Among the published studies, participant weight loss while using low-carbohydrate diets was principally associated with decreased caloric intake and increased diet duration but not with reduced carbohydrate content.”

      OK this one gets me slightly peeved…

      You have studies from 1996 – 2003…

      The whole fat is bad, carbs are good hypothesis (Ancel Keys is the “scientist” responsible for this whole mess) started in the 70’s… after that the US government decided to issue food pyramids based on Key’s flawed data.

      After that almost all studies were conducted from the assumption that low carb (and hence higher fat/protein) were bad. In double blinded studies this sort of bias could still influence the interpretation of the results, because whilst the measurements were blinded, the analysis and reporting is not.

      In DIET studies that by definition CANNOT be blinded (people know what they eat, and researchers know what they are eating), the possibilities for bias are HUGE.

      This is what I like to use the logic of the maths of above combined with the knowledge of what people did eat – you can’t just say – oh well, Palaeolithic man must have been eating rice – we KNOW this is not true. We know what they had available both prior to cooking and after, but prior to agriculture and eating grains. Using the KNOWN nutritional values of these foods, we can determine whether eating 2-5kgs of leaves for 600 kcals makes sense!!!

      The other issue is design… the type of fat used can skew results, particularly if in an attempt to reduce variables (i.e. bias), the participant is fed some sort of “food goo” that is made up of either fat, protein or carbs… this approach is often results in bias towards carbs, as sweet stuff is alway more palatable than protein goo and fat goo (especially COLD fat goo).

      Additionally, often the diet studies do cross overs, with LESS than the 2-4 weeks that is recognised for the human body to get off the carb addiction and firing efficiently on the fat burning mode – hence AGAIN they bias the results, as often the participants will feel fatigued and drop out – like ALL addictions, slowly removing carbs and weening off is the approach to reduce withdrawal symptoms – although cold turkey gives the best results if you can get through the initial stages!!! 😉

      Finally (for this one) the conclusions do NOT mean low carb diets are NOT the best nutritional approach – they just mean these studies, with all the possible flaws in design they would likely have, cannot say they are good OR bad… so what?! At a minimum this conclusion means that low fat/higher carb diets are the SAME (as this would have been the comparison diet!!!)… so if there isn’t enough to say low carb isn’t good or bad, then the SAME can be said of the comparison.

      Finally, look at one of the criteria for the “particularly” exception – less than 20g/d of carbs!!!

      WHERE on this site, and WHEN has ANYONE suggested less than 20g/day (OK on a fast day you get less than 20g/day, but you also get ZERO fats and proteins!!!)… the recommendation is 50-100 for weight loss “sweet spot” and 100-150 for maintenance… this is WAY above this criteria!!!

      I do note your statement that you are more in agreement with all of this now… although I noticed all these citations and statements, which suggests you are still holding out.

      I REALLY do hope you don’t mind me bashing out these monster replies, but each point is worth addressing, and hopefully you WILL keep looking into this.

      Trust me, as I said I came from the most CONVENTIONAL WISDOM of industries (Big Pharma), and I was skeptical at first… However the science DOES support this approach, but it means going beyond nutrition science and drawing on evolution, biochemistry, anthropology, history, politics (BIG PART of the nutrition policy debacle) and economics (lets face it – if we never jumped onto cheap nasty carbs, probably AT LEAST 50% of the human population wouldn’t even exist – removing grains from your diet (particularly corn and soy products) means 80% of what is in a supermarket is now inedible!!!). Lastly you need to apply natural skepticism to “official” views and have the ability to apply some logic (as above – 5kgs of leave PER day – not likely!!!)

      When you taking a broader multidisciplinary view to the question, the answer is ALWAYS the same – the human body (and that of all animals once you include the fatty acids created the symbiotic bacteria in herbivore intestines) runs optimally on a diet predominately consisting of fats, protein and a FEW carbs.

      This is how Charles Darwin came up with evolution by natural selection. He was not stuck in one view of the world through the eyes of biology, he also recognised and understood geology and geological time (which immediately gave him more than 6000 years, he understood environments and climates and recognised ecological niches, which allowed him to recognise the similarity of “role” that certain animals had in many different countries and ecosystems (an apex predator, the small mammals, rodents, birds, ruminants, each with a similar evolutionary niche in their environment. And finally he was a keen observer and was willing to discard what he thought he knew about the world and was taught about how all the animals and plants came into being. He also had the ability to use logic to look at seemingly different data and see that one thing lead to another and it was consistent with what was observed… This is why he is the GREATEST scientist that existed… he literally changed our understanding about EVERYTHING… what is more, what he proposed was before the explosion in fossil discovery, and then DNA, both of which reinforce his insight into how things evolved on this planet… Was he 100% right – NO, but he was a damned side more correct than the official view of the world.

      So I can only encourage you to look beyond nutrition journals (all your citations are from nutrition journals) and read some journals in the other areas I mentioned above, and even more areas if it adds to the knowledge of this area. Also, don’t just read journals… read books and blogs and websites (they are NOT all intellectually lacking – granted most are)…

      Anyway, I rarely post here, and usually I have my say and then leave everyone else to have their say for a good 3-6 months (check in every 2nd day and read 1-2 articles a week though), so I will leave this MONSTER post as my last for now.

      Good luck with your exploration of this topic, I know that like your views on ketones have shifted, the more you look, the more you will realise that there is a better way for human nutrition… the fact you are so qualified and discovering this now is brilliant, as it may mean as an insider you could change it all!!!

      Over and out!!!


      1. Hey, I REALLY appreciate everything you wrote down here. That was an amazing summary. It really helped me connect the dots.

  123. I guess everybody sees what they look for, I see “there is insufficient evidence” as “there is not enough evidence yet”, others see it as “this is proof against it”.

    Oddly, I just posted another study, done by the Heart and Vascular Institute of the Johns Hopkins University School of Medicine and its conclusions were predominately in favor of a LCHF diet. Of course they had to throw in the meaningless phrase, “healthy fats”, but at this point, such is to be expected.

  124. Actually, reviewing how that study was done, the phrase should be read, “We were unable to find sufficient evidence”… the evidence is there, you just have to know how to look for it.

  125. Just ran across this, thought it might be of interest here –

    “The athlete with more efficient fat conversion moves at a faster pace when fat is the main energy source. In the 1989 Hawaii Ironman Mark Allen ran a 2:40 marathon (the fastest recorded in the event) following 5:30 of hard effort. No human has enough carbs left on board to sustain such intensity for 8 hours. In a state of carbohydrate-depletion, his rate of work in the marathon depended on an ability to oxidize fat at a rate of 1.15g/minute, which is roughly 50% higher than most national-class athletes can achieve. An average level of fat oxidation (.76g/minute) would have produced a much lower rate of work and a time for the marathon of 3:30.”


  126. OK, It held my previous post for moderation because of the link, but here’s the quote (below). I’m thinking about doing a 200 mile hike while fasting to see if it can be done. I’m pretty fully keto-adapted to moderate exercise, and have fasted for 3 and 5 day periods while walking 3-4 miles a day. If I get a break in my classes, it might make a good experiment.

    “The athlete with more efficient fat conversion moves at a faster pace when fat is the main energy source. In the 1989 Hawaii Ironman Mark Allen ran a 2:40 marathon (the fastest recorded in the event) following 5:30 of hard effort. No human has enough carbs left on board to sustain such intensity for 8 hours. In a state of carbohydrate-depletion, his rate of work in the marathon depended on an ability to oxidize fat at a rate of 1.15g/minute, which is roughly 50% higher than most national-class athletes can achieve. An average level of fat oxidation (.76g/minute) would have produced a much lower rate of work and a time for the marathon of 3:30.”

    1. Athletes consume carbohydrate during these types of races. Mark Allen consumed carbohydrate during this race. They are not carboydrate-depleted.

      1. Well then, there you go. No need to even think about this anymore, we have our answer, since “Athletes consume carbohydrates during these types of races” and Mark Allen is an athlete in once of these types of races, presto facto, he clearly ate carbohydrates during this race, which proves that all atheletes are not carb depleted during these types of races, because they all eat carbs… A perfect circle of logic, defended from all sides, preventing the need to ever learn anything we don’t already know. Thanks Seth! And BTW, your links to that were fascinating!

  127. Thanks Bill Dewitt….for the post about Mark Allen in the ’89 IRON MAN run…
    Take that …Mr. “bag of cornstarch”…
    LOL GROK ON>>>

  128. Why does the myth that the more you exercise (read, athletic), the more carbs you need to fuel energy?

    In exercise, as in daily activity, protein converts to glycogen in the absence of carbohydrates.

    I have cycled (mountain biked) up the Andes (now this was day in day out for over 17 days) and many similar terrains. I have run 10km+ fun runs and run around 8km at least 4-5 times per week and neither I or my performance has suffered. In fact most people are astonished that I can perform at the level that I do on “low-carb”.

    I have also lived and traveled extensively in Asia. Westerners assume Asians eat rice in the same quantities that we do when we frequent an Asian restaurant.

    They do not. The Japanese would eat a finger bowl of rice and then leave some in the bowl. The Chinese would eat a finger bowl of rice. The Indians eat the most rice. Asians do not pile their (large) bowls up, Mt Vesuvius high and then order second and third servings of rice to “mop up the sauce”. In an authentic chinese restaurant (in the US, UK), the waiting staff are often surprised when tables order more rice than served initially.

    Finally as to comments that carbohydrates are older than “civilisation itself” – this is true. Carbohydrates were probably on this earth before primates even got to the trees.

    However, man eating carbohydrates is not as old as civilisation itself (other than in PB quantities). Man only began harvesting wheat and grains 7k or 20k (Im sorry, I forget which) years ago!.

    Finally addressing the same posters comments – if we only ate the amount of carbs that our grandparents did, we’d all be fine. The copious consumption of carbs at every meal and even as meal substitutes is a very modern day phenomena (about 50 years and getting worse each subsequent decade).

    Epigenetics aside, it takes much much longer than that for evolutionary changes to occur. We will not see the evolutionary changes required for some 100,000+ years.

    Keep up the good work Mark.

    A fantastic site.

    ps I have been low-carbing/PB’g for 11 years now!

  129. Anecdotes are indeed poor evidence Seth, but not nearly as poor as imaginary, untested, hypothetical situations which are asserted to work out in favor of your point of view. Mark provided his working definition of the term “prefer” and someone choosing a different definition and using that as an argument is a classical fallacy, which your education should name for you.

  130. none of you clowns can reproduce evolution purposefully in a laboratory but it all happened by accident in some swamp somewhere…sure glad those fruit trees crawled out of the oceans and planted themselves and the bees elovled themselves to pollinate them

  131. Great Post! I missed this post on my own personal holiday. Something about May 19th that always comes up for me.

  132. Nutrition has always interested me, but I’m one of the “outliers” in the graph, being that I have always been classified as underweight. I would love to gain weight (lean muscle, of course) but nothing has worked so far.

    Considering the common weight concerns in the nation right now, many people look at me with a mix of jealousy/envy/anger if I mention that I would like to put on a few more pounds to hide my skeleton. I feel like it is accepted as OK to be looking to lose weight, but arrogant, or even insulting, to be looking to gain weight. Let’s just say, not many people understand my situation.

    I’m 33, male, 6ft, 152 lbs. I’ve tried heavy weight lifting, protein shakes, raw eggs, etc, etc, but nothing seems to work.

    Just curious as to what the PB diet could offer to me. I’ve always planned to live till 100+( original plan was to be on Mars, but, oh well), but just now getting serious about that joke. 🙂

    Any advice on healthy weight gain diets, or longevity in general? I’ve also seen studies related to fasting and longevity, and would love to hear thoughts on that.

    An underweight (yes, we are out there) nutrition hobbyist.

  133. So why does fruit taste soooo amazing then? And why am I not at all fat with a high fruit diet. I do have lots of energy.

    Saying all carbs are the same is like saying all fats are the same.

  134. Hi,

    I understand all of this, but what if my goal is to gain weight and build muscle?

    I’m in my early 20s and began the paleo diet in 2008. I just recently stopped a few weeks ago because I wasn’t seeing any muscle growth and felt weak in the gym. I now eat rice before working out and have the energy to lift heavy. Prior to the paleo diet, I was a bread addicted teen and always ate low-fat. I was 130 and 5’8 (more muscular). When I went paleo, I went down to 120 (lost muscle, no energy, but no acne!). I tried increasing fat while on paleo, but still had little energy to lift.

    Am I just better suited to eating more carbs?

    1. If you lost weight beyond excess fat, you probably weren’t getting enough calories. The paleo diet has far less variety than a carb heavy diet, and just requires a change of habit. Utilize fat sources, such as olive oil, coconut products, and seeds to boost your calories intake.

      Takes a bit getting used to when we are used to eating a bit of meat with a huge serving of mash potatoes or rice. Or whipping up some beans, or cranking out a huge bowl of cereal just for the heck of it. Or downing an entire pizza.

      Remember, lean mean isn’t that calories heavy. 4oz of lean chicken only has like 110 calories. So a plate of chicken and vegetables might be anywhere between 200-300 calories. You’d have to eat 6+ meals of that to get enough calories if you were lifting. Again, I think it’s all about utilizing fat sources.

  135. I remember when I was doing “Body For Life”, and after 5 weeks I got so frustrated that it was not working, I called the 1-800 number and they told me that the people who succeed on the program i.e., the ones who win the $$ are the “genetically gifted” types that Mark posted about above. Wow! What a scam! I was working out 6 days a weel and following the diet to a “t” with no results.

  136. Hi Mark,

    What happens to a dietary fat that was not used as energy? Say due to an individual’s inactivity.


  137. To the skinny ones, I’m skinny fat too due to fructose malabsorption (otherwise I’d probably just be fat!). Try picking low fodmap vegies and getting enough omega 3s and protein, as well as less omega 6s and more sat and mono fats. I’m just trying this now, after researching fats and then finding this site. Make sure you get heaps of vegies, there’s not much carbs in them.9 cups a day is probably ideal according to Dr Wahls.

  138. Don’t mind the theory, but have some issue. Especially when comparing these concepts to the diet of “primitive” man.

    A) There is no real evidence of what early man actually ate, but what we DO know points to not only meats but a diet high in sugars from fruits/vegetables, and actually rather LOW in fat since wild game, fish, and birds tend to be very lean. Saturated fats would be on the low end, most being poly/monounsaturated from nuts.

    B) If carbs impact longevity and health, please examine and explain far east culture. The Japanese are among those with the longest life spans, and leanest physiques on the planet. Their diet is RICH in rice products, and vegetable starches.

    C) The leanest and most healthy athletes are among fitness models, bodybuilders, runners, etc., all of which recommend high-carb diets. The reason they recommend them isn’t because they’ve been “brainwashed” by society – but because fat simply doesn’t deliver high-impact energy, and they see it first hand when they train. The only thing these athletes say about low-carb, is that you get thin, like for contest prep (and thin does NOT=healthy).

    I could understand this for a sedentary person, someone who doesn’t want to exercise and wants to become “thin,” where thin=healthy in their minds, but for a high performance athlete, there’s no way – those are very rare cases for a reason.

    Sorry, I’m going to go with what all 99.99% of the world’s elite athletes, and healthiest, active (present day) cultures do. Eat carbs.

    But good luck everyone!!

    1. The elite athletes MUST eat lots of carbs because they have so little bodyfat and they train HARD. Fat truly IS the preferred fuel for exercise and resting levels below 50-60%VO2max. Even a slightly elevated heart rate above the resting heartrate still burns 90+% FAT and only 10% glucose. But endurance athletes train at levels much beyond the body’s ability to continue to provide free fatty acids to the muscles to be oxidized (burned). Their bodies flip from aerobic to ANaerobic and the fat:glucose used ratio decreases, i.e. they MUST eat carbs to continue performing at this level or they HIT THE WALL. THAT is why they “recommend” high-carb diets. But if you are not as active, this many carbs (read: CALORIES) will make you FAT, period. These athletes also eat 3000-5000+ calories a day. Are you going to do that too and remain a non-active adult? You’re reading too much into their “advice” and CLEARLY do not know the WHOLE story lol.

  139. Vitamin C is a nutrient absent from meats and vitamin B12 is a nutrient absent from plants.

    If you went on an all plant diet, you would get a lot of vitamin C, but no vitamin B12 and then die.

    If you went on an all meat diet, you would get a lot of vitamin B12, but no vitamin C and then…still live.

    Vitamin C is a non-essential nutrient, the body can do fine even without it. Vitamin B12 deficiency is a terrible thing.

    1. Not so. Inuits ate fermented animal products and suffered no effects from vitamin c deficiency. I’ve even heard that the skin of seals is rich in vitamin c, but I cannot remember why. Fermenting foods, which most meat-rich cultures does, ups the vitamin content of meats.

  140. A dietitian once told me I was making a bad decision by not eating any desserts because NOT eating desserts is a BAD thing because once I get the chance to eat it after a long period of abstaining from it, I will end up binging on desserts.

    That’s like saying to an addict that NOT smoking or doing drugs is a BAD thing because once he or she gets the chance to do it after a long period of abstaining from it, they will end up binging on illegal and harmful substances.

    This comment of mine was made possible by Noel Dibish, RD, who is an overweight dietitian and is apparently one of the “top” dietitians at Kaiser Permanente (Union City, CA branch I believe). She also says that high-fructose corn syrup is “not that big of a deal”, and that getting fat or losing fat is a simple matter of the foolish “calories in vs. calories out” concept. Thanks but no thanks, I’d rather have my dessert-free healthy body with some grains (not 9-11 servings like the way you advocate) to match my low physical activity level than to have your body with a ring of carbohydrate loaded fat cells and intestines full of putrefying junk. If you want to spent some “quality” time at a “hotel” full of people in white coats, follow this dietitian’s advice and you will have her to thank in no time.

    Now without further ado, I have a bowl of white rice to eat and a ricks

  141. A dietitian once told me I was making a bad decision by not eating any desserts because NOT eating desserts is a BAD thing because once I get the chance to eat it after a long period of abstaining from it, I will end up binging on desserts.

    That’s like saying to an addict that NOT smoking or doing drugs is a BAD thing because once he or she gets the chance to do it after a long period of abstaining from it, they will end up binging on illegal and harmful substances.

    This comment of mine was made possible by Noel Dibish, RD, who is an overweight dietitian and is apparently one of the “top” dietitians at Kaiser Permanente (Union City, CA branch I believe). She also says that high-fructose corn syrup is “not that big of a deal”, and that getting fat or losing fat is a simple matter of the foolish “calories in vs. calories out” concept. Thanks but no thanks, I’d rather have my dessert-free healthy body with some grains (not 9-11 servings like the way you advocate) to match my low physical activity level than to have your body with a ring of carbohydrate loaded fat cells and intestines full of putrefying junk. If you want to spent some “quality” time at a “hotel” full of people in white coats, follow this dietitian’s advice and you will have her to thank in no time.

    Now without further ado, I have a bowl of white rice to eat and a rickshaw to haul.

  142. Here’s something I did. It’s nothing close to primal, but it worked. While I didn’t gain any muscle, I did not lose any either. I lost 5 pounds of fat and I can attest to that by being able to feel more of my bones and abdominal muscles after this diet. I also woke up at 7:00AM and went to school which required walking every 45 minutes to the lockers and between classes, and walking to the bus. I was two months from turning 18 at the time.

    For every day for one week, this is strictly what I ate:

    – 1/4 cup of oatmeal

    – 1 bowl of rice (2/3 cups if the quantity of that rice was raw)
    – 1.5 bowls of a tofu based dish (When I say bowl, I’m referring to those typical blue and white Chinese bowls)
    – 1.5 bowls of vegetables (vegetables were always eaten after the rice and tofu)


    After doing this for one week, I did not gain any muscle, but I did not lose any either. I could feel my bones and abdominal muscles more “clearly”. I am really sure that I consumed at least 126 grams of carbohydrates every day from the oats and rice. What’s going on?

    1. It’s called starvation. You are eating well below the amount of calories you are burning daily, and it is taking an unhealthy toll on your body (and you probably did lose some muscle mass in the process). You should never eat below your basal metabolic rate. You should eat between your basal rate and your TDEE rate if you are trying to lose fat safely over time (Google ’em). Of course you lost weight, but this strategy is very unhealthy and totally unsustainable — and it will make you crave lots of food soon enough 🙂

  143. Why go on about eating primal at all? Human digestion, pallate, enzymes, & diet has significantly evolved since man was hunting for food. And in some parts of the world, meat was rare and humans evolved to primarily live on plant, seed & grain.
    Science has proven that we need some carbs to function optimally. Sure we can live without it, but live nutritionally deficient. Just like vegans live nutritionally deficient.

    Don’t forget that fibre, an essential part of our diet, come from carbohydrate sources.

  144. Fascinating dialogue on carbo-load vs Paleo.
    As a once practicing (but not professional dancer,) who frequented professional ballet, modern, ethnic, dancers, it was standard to follow the Steak and Salad diet day in and day out, “working out” all day and late into the night, most nights.
    The “Balanchine diet”, when properly followed, with lots of vegetables, is efficient and healthy long term, when not followed by neurotic individuals. Not exactly Paleo, but add a little butter and bacon here and there.

  145. I’ve been very low-carb for quite some time now – just over a year, and I can attest that once keto-adapted we do NOT need carbohydrate for our energy resources, IF we eat enough calories.

    There’s many on here saying they had little energy on paleo, etc… which is common when you move to a lower-carbohydrate diet IF you don’t take in enough calories.

    Most studies that compare low-carb to low-fat diets for weight loss also note that the low-carb groups often ate significantly MORE calories than the low-fat groups, yet still lost MORE weight. As such it makes sense that moving from a higher-carb diet to paleo would involve taking in more calories, unless you were already calorie-heavy to begin with, in order to maintain energy output.

    For me I lost nearly 100lbs in a year without any calorie-restriction. In fact, I started at 2,800 calories a day and increased it to over 4,000 because I didn’t have energy on 2,800… Some days I ate over 5,000 calories.

    Most days I ate under 100g of carbohydrate. On my 5,000+ days I’d eat up to 150g of carbohydrate. I was also fueling 5hr+ cycling sessions through the Canadian Rockies on those days… while low-carb.

    Now that the warm weather is gone (and the vast majority of my body fat) I don’t spend 5 hours in the mountains and don’t need to eat as much… I still eat around 2,600+ calories, depending on the day. I often eat under 60g of carbohydrate daily right now. Basically, under 10% of my daily calories are from carbohydrate.

    I continue to exercise (usually HIIT) anywhere from 10hrs a week plus, with no issues affecting my ability to do so, even when eating under 60g of carbohydrate a day.

    But then again, I make sure I;

    1) Eat enough calories, and;
    2) Maintain my Fat/keto-adaptation

    And that’s what makes the big difference for me. Trying to lose weight and fuel activity without enough calories, or while taking in too many carbs doesn’t necessarily work well.

  146. So I am new to all this. I have a friend who is a huge proponent and I’ve been at it for a week. Last Friday I was diagnosed with fatty liver disease and my pcp was telling me to cut back on my sweet intake and eat more whole grains.

    I gave him the Steve Austin six million dollar man raised eyebrow.

    As far as excess sugar and sweets, a teaspoon in my coffee or tea, and desserts really only on holidays. As for whole grains and such, it’s the only bread I consumed. So when I told him this he told me to keep at it and just exercise. Well I will admit that I am not the most physically active, but looking at me you would never think I am “dangerously close to clinical obesity”. 5’9″, 208, 34 in waist. No, I’m not in the greatest shape but when I have an image of what obesity is-put there by clinicians-I am not thinking of myself.

    Obviously, I don’t quite buy into all that conventional wisdom. For better or worse, I am a scientist by trade and need to observe, test, and justify things for myself, which leads to my question:

    Where are you getting your research? Not to say what you are saying doesn’t make sense or isn’t logical, but you referenced that the data I’d “piling up”. I am just curious as to what that data is and where I can find it. I am not one to take science lightly. I didn’t believe the moon was tidally locked with the earth, so I did the math to prove it. I was in the fifth grade (point being is please don’t take it personally).

    I have another friend who is a registered dietician whom I’m giving hell. I challenged her to tell me what special thing grains give me that veges don’t. Her answer was “it’s the combination of what you eat with grains that you may not get elsewhere.” so I said basically they are delicious and that’s it, because that is not a scientific answer.

    So, I’m just looking for a little more buyin. 🙂

    1. Hi Jeffers –

      Fellow scientist (retired) and equal opportunity skeptic here. Also fairly new to any form of low carb lifestyle, including Primal Blueprint.

      I also have had a similar medical encounter which I am currently sorting through. I don’t eat junk food, drink sodas, consume refined or processed anything, fried foods and so on. I was raised in a health conscious family and raised my own children on home grown organics and grass fed beef, etc. etc.

      To tell someone like us – change the diet to improve health – followed by something like “oh, well, then keep up the good work just cut back a few calories and walk an extra hour every day” is just – what – weak?

      How do fatty infiltrates form in the liver – or other health issues like metabolic syndrome arise – in someone (1) with good genes (2) not taking meds prone to these side effects (3) not eating a terrible diet or (4) lacking in recommended exercise? I EXCEED the exercise and diet recommendations for pete’s sake!

      I hope that Mark responds to your request for more evidence based references. Meanwhile, at this point in my own research – both giving the low carb lifestyle a trial and searching the literature – I have found the answers that my heavily credentialed MD (internist) failed to provide.

      In a phrase – carbohydrate intolerance. Evidently, 3 of 4 people develop carb intolerance at some time in their lives. Health issues follow.

      If you want to read a book based on evidence – written by two of the researchers who conducted 30 of the more recent low carb studies – you might consider:

      “The Art and Science of Low Carbohydrate Living”, (2011), Volek, J.S. & Phinney, S.D. ISBN 978-0-9834907-0-8.

  147. Well i was a follower of you until i read this post… Get to low on protein and fat and you will die????? first and foremost, you CANT get to low on protein, you could eat nothing but FRUIT and still get enough protein, mothers breast milk is ONLY 5% or so protein, and that’s the food of humans during there most rapid growth in size. And fat????? the need for essential fatty acids is only like 1% of daily intake. Mark, biologically humans aren’t carnivorous which is what your trying to make it sound like. When children are born they don’t remotely find meat or an animal something to salivate over. I’m sure you know humans secrete CARBOHYDRATE digestive enzymes in the saliva, and our stomach acid is A LOT weaker than carnivores, we don’t have amino acid taste buds, that’s why we have to put a bunch of salty or sweet flavoring on meats so we can taste anything at all, or just because the high level of sodium already in the meat for storage purposes allows taste.. Don’t get me wrong i eat meat, but we were absolutely NOT originally designed to consume it.. The human anatomy tells us that in NUMEROUS ways.. BTW you know that fat just gets converted to glucose or glycogen for fuel right? same as carbohydrates. I have no clue why I posted this comment because I KNOW you KNOW all of what I just said, and a whole lot more, I just don’t know why you are telling people lies.. The only possible way to die from a protein or fat deficiency is to starve yourself by eating NOTHING AT ALL

    1. Whoa, hold up a minute Tc….Please see my response (above) to Jeffers.

      I agree with you that humans are NOT carnivores much less obligate carnivores. We are omnivores – as supported by plenty of credible evidence. We DO have several evolutionary lineages of amylase – in the mouth as well as the pancreas.

      YET – I agree with what Mark is saying about the relative importance of carbohydrate, protein, and fat. The science that he is basing his statements on – if not referencing – is true.

      In fact, as we proceed through the adaptation phase from carb fueled organisms to fat fueled organisms, our protein requirements increase dramatically. Once we are through the adaptation phase, our protein needs return to the level regarded as adequate for high carb diets. Reason being that during adaptation our ability to metabolize protein temporarily loses efficiency.

      I found that utilizing the FitDay.com food log – as Mark suggests – helps me monitor my protein intake as well as my carbs and fats. I was doing just fine with the fat/carb ratios but needed to increase my protein intake. Doing better on more protein.

      For more of the science, see “The Art and Science of Low Carbohydrate Living”, (2011), Volek, J.S. & Phinney, S.D. ISBN 978-0-9834907-0-8.

      Btw, It is NOT true that human’s don’t have taste buds for meat. The amino acid taste receptors are TAS1R1 and TAS1R3. Meat may be relatively tasteless for some people – as are grains evidently for some people – but as a super taster I can promise you that meat all by itself – raw, semi-cooked, or fully cooked – has wonderful and varied taste.

      1. PS. The group of taste buds for meat are the “Umami” buds.

  148. What about this way of eating for diabetics? I am a pretty active one and was just wondering….

  149. Hi.

    All I eat is a bowl of bran flakes with fresh full cream milk and 2 cups of coffee (ricofee, 2x spoons sugar; milk)

    I quit eating bread (both white and brown) Sunday 4 March 2012

    Is that being healthy?

  150. I understand the carbs but I don’t understand the fat yet.How do you know how much is good for your diet? How much of your calories on a 2500 day should be fat,how much protein? My husband is trying to lose weight and I don’t want to overdue. I want to get it right. Should he have 20% protein and then what % should be fats. He plays basketball a couple of times a week but is not an “athlete” and does not do any training. And for a woman who does not want to gain weight (I am going along and enjoying this along with him since he brought it up) how do I fit fat into my diet?Thanks for any help!

  151. I guess what I am looking for is a fat,carb,protein ratio and it is the same for everyone if weight loss is the goal? Sorry but I am very new to Primal and trying to learn ….. 🙂

  152. i would agree with more protein and fat diet,and next to not at all carbs,if only not all good nutritionists didnt say that animal protein is toxic for human species cos we evoluted from primates whaic are primarily or even exclusively vegetarians. so what about it? can anyone answer this,please. i am an easy person to switch this very minute to high protein and fat diet cos i am not a sugar lover and i dont eat sugar at all. but nutritionists say brain works on glycose not on fat calories. i believe they know wht they are talking about. and i know a top nutritionists who has been an exclusive vegetarian,maybe the word is vegan,for almost 30 yrs and he is slim. so i am confused. i am rady to switch on protein fat diet and i CAN fast cos i have a strong will and my mood does not drop when i am hungry and hungar passes soon anywhy. but i am worried for my brain and my heart muscle cos i have a heart condition and dont want to stain my heart even more than it is already strained. can someone tell me what to do.i am 64,a female and physically active but i cant work,i only walk a lot. thanks.

  153. Lots of good info in this blog!

    I’ve been on a very-low carb diet for about 4 months now and have lost over 40 pounds while leaving behind almost all of my former health issues. I also have far more endurance and energy than I did before. My muscle mass is growing. I typically consume fewer than 20 carbs per day, most of those from leafy vegetables and things like peppers and green beans.

    People commenting here generally seem to be cherry-picking and taking a narrow view to support their own experiences and opinions. That’s ok: That’s what people do.

    If you are young and very physically active you can likely consume a carb-based diet and be very healthy. Once you are no longer as active you will likely get fat very quickly on that carb-based diet. It happened to me and many other fitness gods I personally worshiped who are now waddling around in mom jeans now that they have hit their mid-40’s.

    No one is going to be able to come up with a precise ideal diet that works for everyone. Diet is very individualized. But as much as doctors vary in general recommendations for their patients, you likely won’t find a single one of them recommending more refined carbs and sugars. Why? Because refined carbs and sugars make you fat and unhealthy. Now, try to find a doctor who recommends you get rid of all protein and fats from your diet because they make you fat and unhealthy.

    And although I am not a devoted enthusiast of the paleo/primal lifestyle or ethos, I will point out that agriculture itself is a relative innovation. And although primitive humans were not entirely carnivores, they sure as hell didn’t have bakeries.

  154. Did you ever think about whether or not the world can economically and environmentally afford to all go primal? Perhaps we should be less concerned with how you can over eat a bunch of meat and instead eat an appropriate amount of a balanced *economically and environmentally sustainable* diet. I promise you won’t get fat if you only consume as many calories as you need.

  155. A couple of basic questions. What was human’s source of fat 2 million years ago? Or even 10 thousand years ago for that matter? Also, what kind of magic enables cows to create fat from eating plant matter? Think of how the answers to these questions fit into your paradigm.

  156. I was a vegetarian for about 15 years & never ate much meat before that. It’s an emotional/mental thing with me. In the last 3 years I have survived colon cancer & breast cancer + chemo & radiation. As I am now on an estrogen suppressor, I was told to eat very little soy. So I started adding meat back in my diet. I have been SO conditioned to eat grains & fruit, though never ate true junk food. It is difficult to “unbelieve” these teachings & get over the mental part of eating meat. I now also suffer with joint/muscle pain & headaches. Any recommendations? I just want my health back now.

  157. Quite by accident I decided to stop all flour and sugar consumption upon moving to a new apartment just for a what the heck it can’t hurt reason. That was October 3, 2011. At one month, I had lost 15 pounds upon a new doctor visit and was shocked. I have continued a loss from 233 pounds (eating healthy, nutritious whole grains foods) to 176.3 pounds today May 4, 2012 (eating protein, fat, and low carb meals). Switched to coconut oil 3 years ago, so most fats are that and olive oil. Dairy almost none, fruit small amount couple times of day, tons of fresh vegies and small amount of russet potatoes and egg for breakfast and some nicely buttered popcorn, small amount for night snack. Yes, those are carbs, but the fat is still melting, so am listening as my body selects what it wants. I’m not just loosing weight, but inches more than weight at this point, but literally feel and see it drop off, sometimes on a daily basis!!!! Had the old lady “hamhock” forearms, that are completely gone and youthful now. Found Mark’s website and am getting good ideas, info and recipes to pass along to others. So far no one has taken up my challenge to see if it would work for them. Their loss – but I love my new way of living — The Primal Diet is for me always!!!!

  158. Hi:
    I don’t think the information here is neccessarily correct. It may be for the American diet, but after many visits to Asian countries (mainly Japan,) these are places that eat rice daily. Yes, in small amounts but a couple of times a day. Also, Italy which does eat Pasta daily(also, in small amounts daily,) have lean populations.
    As an aside: My cousin last year went to Italy and Sicily for 3 wks. Her luggage was lost and she had to buy all new clothes to wear for the whole trip. She had to travel to Rome to get an American size 10/12. They did not have her size in any regular stores….I kid you not. By the way she is 1st generation Sicilian. I have been to Italy and they are petite. So my point is it is really simiplist to state that all carbs are bad. I think what happens is we DO eat to MANY unrefined carbs.

    1. Where did Mark say “all carbs are bad”? Mark is a runner. He KNOWS when carbs are absolutely necessary to keep energy going during high intensity and long endurance style training, but for MOST of the populace, who are underactive and overweight, eating less carbs (and eliminating refined, processed, GARBAGE carbs) while eating more NATURAL, NON-REFINED fats and proteins to make up the caloric difference (while still retaining a slight deficit below their TDEE but above their basal metabolic rate) simply works in the real world. It’s science baby!

  159. How many gram of fat do I need with no starches? My goal is minimum 3000 calories daily! Trying to gain 1 lb lean muscle /week.

  160. Can someone tell me if I really need to eat protein every 2-3 hours to prevent muscle breakdown? How many grams fat should a 3000 calorie plan have?

    1. Yes and no. Anytime you are in a post absorptive yet active state (after eating a meal), your insulin is low and your glucagon is slightly higher. This ratio on it’s own allows for some protein catabolism, BUT every time you eat a meal that raises your insulin, this state allows for protein anabolism. So, your muscles are constantly being slightly broken down and slightly repaired over and over throughout the day. True NET muscle catabolism really would only occur if you were starving yourself for long periods of time. Even fasting up to 18 hours is really no problem as long as you refeed for the other 6 (being sure that they are well balanced meals consisting of both protein and carbs otherwise, in the absense of carbs, the protein will be broken down for energy instead of anabolic muscle repair). On your other question, my OPINION is that you keep your daily fat intake below 130g. for a 3000 calorie diet, this would be a MAX of 39% of calories. This OPINION comes from MuscleHack.com literature. The info above comes mainly from https://www.medbio.info/Horn/Time%203-4/homeostasis_2.htm

  161. all this is no big revelation is it? its really just common sense. don’t eat processed foods, sugar is bad for you etc.

  162. @jan

    to some extent it is common sense, as you say, just lay off the processed foods and sugar
    but wheat? that doesn’t seem like common sense to most people (that i’ve spoken to anyway)
    the majority of people, imo, consider wholewheat to be an important staple of the weatern diet, and to limit it or stop eating it altogether ‘does not compute’ in their minds

    1. baz, I recently read that ancient wheats (as mentioned in religious texts and still can be found today) had twenty-something chromosomes but the stuff today has in the forties. Three of those were not selected for but came about anyway – they induce addiction, pleasure and weight gain.

      The majority does not make it right and the majority does not listen to the needs and reactions of the body as they did in even the recent past. That is where we are trying to travel on a primal diet.

      I found the sugar addiction the most difficult to overcome. It took me three years living in Borneo where high sugary foods were not easily available but within a year I was addicted again upon returning home.

      On a primal raw extremely low carb and 80% fat ketogenic diet, it took but a few months. As a sugar fueler for forty years, I was amazed how easy is was to shed my addictions on this path.

  163. I think you should make mention of the effect of carbs on people with diabetes and those with pre-diabetes or severe carbohydrate intolerance. I have severe carbohydrate intolerance and I keep my carbs at around 20g a day and never go over 30g. Going higher for me means weight gain, carb cravings and over eating and for Type 2 diabetics it would lead to unstable blood sugars.

    I am trying to eat primal but I have to do it very low carb. I restrict fruit to small amounts of berries and I do not eat root vegetables – e.g potatoes, carrots, swedes.

  164. Thank you for writing this. I get so tired of people spreading the misinformation about carbs. I’ve been overweight for most of my life. Limiting my carbs has been the only thing that has helped me lose weight and pretty much keep that weight off. On top of that, my headaches, heart palpitations, and depression have gone away. Even nutritionist keep this lie going which I don’t understand!

  165. This is a bit of a late read for me and a late reply to make this comment but there are a few things i wanna say:

    Firstly i don’t see any referencing or any sort of indication that this is anything more than what could possibly be someone playing a practical joke on the chubbier people in the community.

    Secondly, i do like this concept and being very interested in nutrition myself find that it does add up in some unseen ways and open my eyes a little bit as to why we rely on glycogen despite such minute stores in the body when we can retain far more fat for fuel.

    Thirdly, i feel that this is dangerous for a “diet” without exercise as people may begin to look that little bit thinner as in their waist size drops a little and yeah sure, their blood sugar levels will inevitably decrease but their body fat percentage will significantly rise if caution isn’t taken leading to CHD’s, high blood pressure and never achieving that six pack or dropping that “cellulite look”.

    Finally, if you are still working on such a thing, please contact me through e-mail as i am very interested in the article and am currently working on a very extensive database for both nutrition and exercise in relation to BMR and making this work as effectively and easily for any individual wanting to use it.

    I have used the USDA database, am currently importing thousands of exercises to try and incorporate everything i can into it from calories burned turning a page in a book to calories burned when eating a sandwich. My database already includes converters, the food database, individual BMR and a weight loss/gain/maintain system. I am putting in an individual RDA for every possible ingredient in food from Ash to Sodium to make it the most extensive and useful system to date.

    If you would like to contact me about this, i would be more than happy to work with you over the internet to include this “Primal lifestyle” as an option within this database and therefore provide more testimonials for creating the awareness that you are so sure of.

    As priorly mentioned, i have not considered this before and have therefore not researched it which is why i have yet to say if i agree or disagree with it however, testimonials are proving to be a strong case.

    Please contact me on
    [email protected]

    Just as an FYI, i have a keen interest in nutrition and have been working towards my degree in sports science since i could with an aim to go into Personal Training, with my interests being in Nutrition i do like to be clued up about it hence the comments and my database.

    Thank you

    1. Ben W, sounds like a lot of work and it has been done to death the past sixty years. Conventional means haven’t worked so far, so what ever makes you think it will with your efforts. I don’t mean to be nasty; the world has only gotten fatter and sicker following modern paradigms.

      The PB by Mark is more than just this one article and if you spend time reading much of his efforts before judging, then you will have a better education than trying the research path you are presently on.

      Conventional ways to health have not worked over the past sixty or more years. Thinking outside the box is hard for some to do but in these times of cancer, obesity and tired health, it is become the only thing to do when convention means have been disproven by their own failure.

  166. Great informative post if your information was only 50% correct.

    There is more than enough scientific research out there to suggest what you are professing is probably wrong and probably dangerous.

    I agree the sugars, manufactured fructose, over consumed fats/oils and processed food (dangerous mix of everything that is poor in nutrition) could be very dangerous to our health but ‘carbs’ are not the issue when they are from natural plant forms i.e. the potato. The potato is a complete natural package of carbs, protein, fat, minerals and vitamins and any other nutrient deficiencies can be added by eating vegetables, fruits, nuts and seeds.

    What we are missing is that the better the nutrient rich food we eat then the better we are going to be in terms of heath, vitality and maintaining a true weight to support our own individual requirements.

    Forcing our body to run in a glucose deficient state only replicates very sparse times in our evolution and the glucose deficient state of turning fat to energy is a safety net to get you through lean times rather than a way of maintain true function.

    1. Wayne, conventional research says the only answer to cancer is cutting, burning and poisoning and the first two have been used for over 110 years, the latter uses the same poisons used in exterminations in WWII concentration camps. And year by year the number of people getting cancer in their life times has risen from one in twenty (circa 1900), one in seven (1970) to greater than one in three today and the rate is growing. Fewer than one in three following the three conventions are alive five years after diagnosis. Pitiful.

      PB offers an alternative to the diet and health measures that have made the world fat and sick. The trend is only getting worse following conventional propaganda. And since you believe in conventional research as it now stands, studies are coming out that cancer feeds on sugar, carbohydrates, starch or what ever name you want to call the stuff. High carb foods demand minerals and vitamins for their assimilation and a conventional or SAD diet based upon the USDA pyramid even when fast food is limited (it is acceptable as a part of USDA recommendations), makes it impossible to get enough of these essential elements with out supplementation. On Primal, essential nutrients can be got from natural unprocessed foods high in animal fats, moderate animal protein and low plant based carbs.

      Remember that it is big pharma doing the research; neither the government nor the universities do meaningful research anymore and both are reliant upon big pharma for their monetary support. The fox is in charge of the hen house so thinking people are beginning to put less faith in the medical powers that have failed in their relentless quest to monetize illness.

      Scientific peer review has made it difficult to impossible for true new research and new ideas, (that do not meet the dogma of the day), getting published. We live in sorry times where science has been usurped by the interests of conventional thinking because of the money being made by old, failing norms.

      Less then one in ten can think outside the box. The modern Galileo, Copernicus or Semmelweis doesn’t stand a chance. Incredible that any thinking person would propose gluttony with sugars over measured nutritionally packed foods from animals and low carb plants.

      1. >>And since you believe in conventional research as it now stands, studies are coming out that cancer feeds on sugar, carbohydrates, starch or what ever name you want to call the stuff.

        There are more ingredients needed for cancer to become a killer than just a food source. As a human I for one need water and oxygen as a priority!!

        >>Less then one in ten can think outside the box. The modern Galileo, Copernicus or Semmelweis doesn’t stand a chance. Incredible that any thinking person would propose gluttony with sugars over measured nutritionally packed foods from animals and low carb plants.

        There are modern day thinkers and experimentalist proving you are WRONG at this very moment.

        One is here http://www.hypothermics.com

        Get out of the dogma and learn EVERY aspect to food!

  167. This was great. I love that you mention Kuhn. It isn’t often I run across someone else that has read, let alone references his Structure of Scientific Revolutions.

  168. Mark: You have not listed any references. Could you post them?

    1. Anthony, Mark has posted a plethora of references. This is one article; there are hundreds, possibly thousands of references to be found on his sites. What is amazing about Mark’s Daily Apple is that for those truly interested in what is being offered here can read, research and find references and then follow the links in his studies.

      Those who want to condemn with out even trying, have made up their minds and of course won’t bother to take even the time to follow the links in this one page.

  169. I have been wheat/grain free for 4 months and love it. However, I am training for a long distance bike race (100 miles) and I am confused on how/what I should do about carbs? Now, my system is sensitive to wheat products and that could be disaster on my race. Can you help? what should I eat for carbs on long training rides of 3-8 hours and what shoudl I eat during my race? Thank you!

    1. Once you are fat adapted (using fat for fuel, not carbs) you can train and ride without fueling up on carbs and your endurance should be much better without the ‘bonking’ or ‘hitting the wall’ you can get when you are relying on your body’s limited carb stores for fuel. Fat is amuch more consistent fuel and your body can store vastly more amounts of fat than it can carbs.

      A really good book on this subject is :https://www.amazon.co.uk/The-Art-Science-Carbohydrate-Performance/dp/0983490716/ref=sr_1_1?ie=UTF8&qid=1348518389&sr=8-1

      1. How can you deny human evolution?

        we CAN and SHOULD eat foods that contain carbohydrate i.e. roots, vegetables and fruits.

      2. Yes, but when exercise increases to the level where your body flips from aerobic to ANaerobic, carb oxidation goes up and fat oxidation goes down regardless. Exercising at increasing levels above 60%VO2max are less than optimal for fat-burning. Also, in the absence of carbs to burn in a continually high anaerobic state, you WILL “hit the wall” and have a hypoglycemic episode (read: collapse) if you don’t slow back down into the aerobic level of exercise which prefers fat burning OR ingest some carbs. Mark knows this well, I am quite sure. References: https://www.abcbodybuilding.com/cardiolayman.pdf and https://www.medbio.info/Horn/Time%203-4/homeostasis_2.htm

        1. Unless you are a skeleton, everybody has fat stores for when your body changes fuel sources even if it is 4%!

          Does anyone have real-time experimental data proving when and how your body flips and the definite need to back this up with eating a specific fuel source.

          You DONT need to consume excessive fats instead the natural starches produced by naturaly grown food sources!

          IGF1, change your ways people or you will die before you want to.

  170. I love this website. Mark you’re smart man. I will like to get your opinion. Every They I under eat during the day. For about a year. I am also construction worker. And I work out afternoons. I am 6-2 Tall .175 Pounds heavy. I am never low in energy And I don’t have to ever count my calories and I will never come by calories. But I don’t have no problem with body fat percentage. Can you tell me Mark please what do you think about undereating doing today and eating large meal and dinner time. Just my ancestors did it for as long as I can remember.

  171. If you live in a state of ketosis, you will not have the exhaustion problems of carb runners. You don’t have to get a 2nd wind to really run fast because you live in your 2nd wind (in a state of ketosis). You sleep better, and if an older male, you don’t need the viagra anymore.

    Also, there is a lot of illnesses that are yeast generated. I have 8 books that tell you to eliminate the yeast from your sugar diet, and your illness goes away within 4-8 days. Each is repeatable and has not failed.

  172. “Glucose is not the preferred fuel of muscle cells under normal human resting metabolic conditions or even under most normal human movement patterns (exercise)”

    You must be kidding…What’s your evidence for this claim?

  173. What would be the Grokkers opinion of taking a male who is slightly overweight and wanting to lose fat but also bulk a little? Should he start with one ratio to shed fat and then a different ratio to bulk some? He doesn’t want to be super bodybuilder type, just a more muscular physique. Thanks in advance for your help!

  174. I just thought I’d add that another thing to also consider is the density of fats vs carbs. The way our body is structured (in the intelligent way that it is) it stores fat more than carbs considering fat is approximately 9kcal/g while carbs are about 4kcal/g. That should light some bulb that if our body is built to store fat that maybe it’s a bit more important than glucose. I really like what you have mentioned and even as a kid, growing up in Ukraine where most people had a super high fat diet, I noticed how healthy people were and the long lives the people lived. There was no way you convince me carbs > fats. Anyway, great read thanks 🙂

  175. Eating a certain number of carbs per day won’t lead to weight gain if energy out > energy in. Think about it. Thermodynamics.

    By the way, “preferred fuel” isn’t synonymous with “only fuel”.

    Further, ingested carbohydrates are converted to fatty acids via exiting the Krebs cycle, so tissues that like to use fatty acids get them from carbohydrates. It’s why glucose metabolism is the central pathway that all other metabolic pathways converge on.

  176. I agree 100%, and it’s been my experience regarding carb vs fat intake. But what about those crazy vegans like that nut Durianrider on YouTube, who recommends 10g of carbs per kg (or was it LB?) of bodyweight, lol. He’s a skinny runt and insists a high carb vegan diet gets you ripped. Now, he is a high endurance athlete… but I’m sure genetics must play a role as well, because there is NO way I could get skinny eating like him, even if I ran 3 hours a day. Thoughts?

  177. What a great article! Such a shame that so many people believe all the lies regarding nutrition and happily consume too many of the wrong foods day after day.

  178. I’m revisiting MDA after a two year ‘voyage autour de ma ‘chambre’.

    Anyhow here goes:

    I think 150g of cho is quite reasonable and seems like ‘high carb’ for some people. So it’s fine.

    I do like to note that to argue the logic of ‘there is no essential dietary carbohydrate as there is essential AA and fat’ that carbohydrate contains the word ‘hydrate’. That is important and should be remembered. They are important from that aspect, but meeting 150 g worth certainly achieves the ‘hydrate’ aspect.

    I have a second question: I know the Kitavans (and I hate to point out to a group whose life style does not approach our lifestyle) are noted to eat lots of cho. I know they also don’t eat all these grains and sugars though. But is it b/c they IF naturally, work a lot (?) and also they smoke a lot? I’m particularly asking about the relation to their nicotine intake and it’s relation to their level of cho they can tolerate. I’m not trying to defend them nor to bash them. I’m just interested in this fact. Similarly how the French tend to smoke a lot, but for them it was the sat. fat aspect that people noted how they were healthy despite this. (They do enjoy their sweet pastries though).

    Mark I am interested in your take on the role of nicotine.

    Thanks, it’s great to be back at this blog after 2 years.

  179. Sugar is the cleanest burning fuel for the body. The obesity epidemic is caused by PUFA, endocrine distuptors, and starch plays a role.

    You can safely over eat on carbs and protein by 2-3x caloric need before de novo lipogenesis occurs. Fat will be stored when caloric need is met. Therefore I support the idea that body fat is simply an accumulation of dietary fat in the tissues.

    Eat less fat, eat more carbs. Eat most fat in the morning, along with protein, and sugar to jump start the metabolism. Support energy production in the body.

    Energy should come from nutrient dense foods – fruit, milk, liver, grass fed whenever possible. Grains, starches, non-saturated fats should be minimized.

  180. hi, just wondering how all this can be incorporated for people/myself with hypothyroidism? I used to be an easy 96lbs, even after two kids…Now 8 months post birth of my second child and on .75mcg synthroid, I can no longer eat like I used to. Even pulling back on my carb intake (one cheat day per week) and exercising x6 week, my weight keeps going up. I never had belly rolls before and that’s what I have begun to sport.

  181. So… If my half blood ancestors “yugoslav”, if they had a diet which was largely vegetables and meat was lesser availability. Relying on pulenta and other processed foods along with white bread as a side to every meal. Relying on these as staple foods that are fround at in this day and time “white bread for e.g. would the man

  182. So… If my half blood ancestors “yugoslav”, if they had a diet which was largely vegetables and meat was lesser availability. Relying on pulenta and other processed foods along with white bread as a side to every meal. Relying on these as staple foods that are fround at in this day and time “white bread for e.g. would the many generations of this style of high carb eating have an impact on the way my boddy handles these processed forms of carbs that have been the way of my ancestors?

  183. I workout on the weights for about an hour. I workout so hard, I’m drenching in sweat.

    I then go for a two-hour walk.

    I need the carbs to give me that energy during and after that exercise (both brain and muscles).

    (I also make sure to include plenty of lost minerals, vitamins and salt.)

    You need carbs for that energy.


    Then marathon runners would notice a difference.

    You don’t think they have tried fats?

    I have.

    It ain;t enough.

    Human evolution didn’t include what we are putting our bodies through, like working out on the weights, and other strenous exercise.

    Carbs are also cheap to eat, and they break down in the body faster.

    Fats also take longer to break down to give us that energy.

    If I was going all day, and not eating as much, then, yeah, the fats would come into play–which they are there for.

    But even then, I would need the carbs for added energy because fats can’t do it very well.

    Carbs also make us feel better (moods), among other benefits.

    Heck, right now I’m feeling a little drained, so I’m gong to go have a bowl of oatmeal and a glass of milk.

    Sorry, Mark, but you are wrong on this one.

  184. Orthodox thinking is a hard cycle to break, people will stick because it is wired into us as a safety mechanism. Great article! Thanks

  185. Hi – I am just starting this diet and really want to be successful with it. Just wondering what you eat for a quick lunch and breakfast – I work, have to 2 young children and so do not have the time to prepare anything lavish for these meals?

    Many thanks

  186. On time post here Mark. I have been shifting my daily intake of carbs and my clients as well to a very low level. I have seen the positive results in doing so, and will continue to use this in my regime. Love all the information you put out on your blog. Very informative. I am a happy reader.

    Thanks again,


  187. Mark,

    I’m enjoying all the benefits of the paleo journey so far. But I also enjoy reading formal research articles in peer-reviewed medical journals. Geeky I know.

    You mentioned in “A Metabolic Paradigm Shift . . .” that “studies keep piling up indicating that carbohydrate intake is the major variable in determining body composition . . ”

    I’m not trying to be obnoxious, but anyway you can refer to actual studies on that?


  188. I’m very confused with all of this. I want to change over to primal eating habits to better my health and lose weight. I’m so confused as to what I should and shouldn’t eat, I still like some carbs therefore what carbs can I eat and be safe. There’s almost too much info out there for us to read. I’ve been reading for days now and still cannot sit down and put together a meal plan for myself. Not to mention my teenage daughter will not eat alot of vegetables so making two meal plans each week is tough. Thoughts? Help!

    1. Safe carbs to eat would rate low on the Glycemic Index.

      An easy way to jumpstart low carb eating would be the Atkins diet. I lost over 30lbs in a few months and there are plenty books and websites that will lay out full meal plans. It’s not heavy on veggies and after you lose the weight you want, you can switch over to a full paleo diet to not gain the weight back.

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  190. Glucose is ESSENTIAL FOR LIFE.Carbs are the go to food.And with keto bodies your brain SUCK and subfunctions.Carbs are friends especially for those of us who are working hard.NEVER EVER EEEEEEEEEEEEEEEEEEEEEEVER a performance of muscular development is OPTIMAL with fat as a prime energy source.Sorry man you are making a tremendous mistake.

  191. I’m New to the PB, actually coming across this by accident as I’m a holistic/sports nutrition student. I have to agree with the Gov guidelines being a little to much in regards to carb consumptions advocating 200+

    I personally have found even as a weight lifter and future fitness competitor lifting 6x a week I cannot handle 130grams a carbs every single day I tend to get hypoglycemic episodes despite being active. A very good coach suggested cycling my carb intake and it has def helped my situation as far as weight management and keeping my blood sugars stable.

    Great article, I look forward to going over some more of your work.

  192. I eat white rice and potatoes EVERYDAY, however, I don’t eat any sugar.
    No matter how rice and potatoes I eat, I don’t gain weight. It is a fallacy to say white rice and other starches cause weight gain. In fact, it is fats and sugars that cause weight gain.
    Try it yourself.