Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
19 May

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.

You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  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. :)

    Crunchy Pickle wrote on May 19th, 2011
    • 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?

      Crunchy Pickle wrote on May 19th, 2011
      • 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.

        Dana wrote on May 19th, 2011
        • I’ve been using FitDay for a while and love, highly recommend giving it a try.

          Nutritionator wrote on May 20th, 2011
      • I use fitday to track and nutrition data to look up a few foods. Nd includes omega 3 and 6 content.

        Primal Toad wrote on May 21st, 2011
        • what is Nd?

          s wrote on January 17th, 2015
      • Crunchy, I started using, 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.

        Peter wrote on June 12th, 2011
        • 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

          Wendy wrote on March 31st, 2015
      • I use some of the free trackers available online. My favorite is You can get a complete nutritional breakdown of whatever you want to track (sodium, fat, carbs, calories, iron, fats, etc.). Another one is;,
        It’s interesting to track your intake for a month or so and see just what your diet may be lacking.

        Mo wrote on December 8th, 2011
      • 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.

        jpatti wrote on September 3rd, 2013
      • You can check 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!

        Pavel wrote on October 7th, 2013
    • 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 !!

      tn redneck wrote on May 19th, 2011
    • 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!!

      Martin wrote on May 19th, 2011
      • 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.”

        Alex wrote on May 19th, 2011
      • Richard loves his fat dude…

        Primal Toad wrote on May 21st, 2011
  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.

    Alison Golden wrote on May 19th, 2011
    • 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.:)

      Melissa wrote on May 20th, 2011
    • 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.

      hexrei wrote on January 28th, 2012
    • I’ll live with you.. No problem here

      jay wrote on June 14th, 2012
  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!

    Don wrote on May 19th, 2011
  4. The “pair of dimes shift” image made me laugh out loud. :)

    melodious wrote on May 19th, 2011
    • me too!!!

      peggy wrote on May 19th, 2011
      • Oh, I get it!

        Paul wrote on May 19th, 2011
    • OK, took me a sec :)

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

      Michael wrote on May 19th, 2011
  5. “there is actually no requirement for any “essential dietary carbohydrates” in human nutrition”

    Vitamin C is a carbohydrate.

    Howard wrote on May 19th, 2011
    • “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…

      Robin wrote on May 19th, 2011
    • 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.

      Dana wrote on May 19th, 2011
      • 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.

        Tim wrote on May 19th, 2011
      • 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.

        Primal Toad wrote on May 21st, 2011
    • The glands of animals are high in Vitamin C.

      Primal Palate wrote on May 19th, 2011
      • I’m impressed you suohld think of something like that

        Keisha wrote on February 16th, 2012
      • 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…

        Travis N. wrote on March 7th, 2014
    • 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.

      Kevin wrote on May 19th, 2011
    • Do you spell ‘anal retentive’ with a hyphen?

      Dick Hyman wrote on December 25th, 2014
  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…

    Peggy The Primal Parent wrote on May 19th, 2011
    • 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. :)

      Crunchy Pickle wrote on May 19th, 2011
      • 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”.

        johnnyrandom wrote on May 19th, 2011
      • 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!

        fritzy wrote on May 19th, 2011
        • 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!

          joiints wrote on May 26th, 2011
    • 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.


      Ketopia wrote on August 24th, 2012
      • 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!

        Diane Smith wrote on August 24th, 2012
      • 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.

        mhikl wrote on February 4th, 2013
        • Oops, 40,000 steps.

          mhikl wrote on February 4th, 2013
  7. Gary Taubes posted his cholesterol numbers yesterday. I was just curious if you plan on posting yours as well.

    Ian in Philadelphia wrote on May 19th, 2011
    • oh, nice one. I’d love to see Mark’s numbers.

      ben wrote on May 19th, 2011
  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.

    Hal wrote on May 19th, 2011
  9. Do you have a link to any of the studies you mentioned? I am curious to read their results.

    John wrote on May 19th, 2011
  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.)

    Harry wrote on May 19th, 2011
    • …having gotten OFF….

      Harry wrote on May 19th, 2011
      • dirty

        sharon wrote on June 6th, 2012
  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!

    College Caveman (Musician) wrote on May 19th, 2011
    • One word response(if I am remembering correctly): gluconeogenesis

      Jaeden Ironwolf wrote on May 22nd, 2011
  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.

    Tim wrote on May 19th, 2011
    • Tim, see that’s what I mean by “reframing.” Nicely stated.

      Mark Sisson wrote on May 19th, 2011
      • 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.

        CavemanGreg wrote on May 19th, 2011
      • 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.

        In wrote on May 24th, 2011
        • BTW – this is only scratching the surface. Much more could be said on this.

          In wrote on May 24th, 2011
        • 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.

          Lbliss wrote on June 11th, 2011
    • 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!

      Cathy wrote on May 20th, 2011
      • 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.

        J. wrote on May 20th, 2011
      • 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.

        Registered Dietitian wrote on May 23rd, 2011
        • 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.

          Dr. John wrote on June 6th, 2011
        • ‘registered dietician’: that tells me all i need to know.

          greg grok wrote on December 17th, 2011
        • 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?

          mhikl wrote on February 4th, 2013
    • ditto

      jan wrote on May 26th, 2011
      • my ditto went in the wrong spot.ugh It was intended for Tim’s reframing statement.

        jan wrote on May 27th, 2011
  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.

    Shema wrote on May 19th, 2011
    • 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.

      Dana wrote on May 19th, 2011
      • 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.

        Bill DeWitt wrote on May 22nd, 2011
        • 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.

          T wrote on May 23rd, 2011
        • 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.

          Ali wrote on April 24th, 2012
    • 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.

      Primal Palate wrote on May 19th, 2011
    • 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.

      Brandon Berg wrote on May 19th, 2011
  14. great post, because this is about so much more than just weight loss.

    Real Food RD wrote on May 19th, 2011
    • 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.

      Dana wrote on May 19th, 2011
      • 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?

        aktres wrote on May 19th, 2011
      • 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. 😀

        Moe wrote on May 19th, 2011
      • 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.”

        fritzy wrote on May 19th, 2011
  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.

    Dana wrote on May 19th, 2011
    • 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!

      robertbarnes3 wrote on May 19th, 2011
    • Thank you for this comment. This puts the “body prefers glucose” statement that I’ve often heard in perspective.

      Michael wrote on May 19th, 2011
    • 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.

      Primal Palate wrote on May 19th, 2011
    • ‘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!

      Rachel wrote on May 19th, 2011
    • “pancreatic panic”……… nice turn of phrase!!

      KL (almostGrok'd) wrote on May 20th, 2011
    • “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

      Bob wrote on May 22nd, 2011
      • 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.

        Monkeykoder wrote on March 7th, 2012
        • 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.)

          Monkeykoder wrote on March 7th, 2012
        • 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.

          Gabriel J Wigington wrote on May 8th, 2012
      • Not true,

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

        Hu Tong Kwok wrote on December 6th, 2015
    • This comment needs a Permalink. Sums up the issue perfectly.

      Adam wrote on May 24th, 2011
      • +1
        Hate zealots–even well intentioned ones

        Rod wrote on July 10th, 2011
  16. Great post! As always. Going Paleo has made gigantic changes in my life! Thank you for what you do!

    Jeanna wrote on May 19th, 2011
  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.

    Renee wrote on May 19th, 2011
  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.

    Karin wrote on May 19th, 2011
    • 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.

      Andi wrote on May 19th, 2011
    • 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%)

      bbuddha wrote on May 19th, 2011
  19. Fatabulous POST MARK!

    … as always, well said… love it!!!


    Steve wrote on May 19th, 2011
  20. 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.

    Neal wrote on May 19th, 2011
    • 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.

      Ed wrote on May 20th, 2011
      • Well sais, I Ed… I like your thinking!

        Milemom wrote on July 11th, 2011
  21. 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!

    jamie wrote on May 19th, 2011
  22. 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.

    Bill wrote on May 19th, 2011
    • 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!

      Martin wrote on May 19th, 2011
    • 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.

      Brandon Berg wrote on May 19th, 2011
      • It would be more accurate to say that glucose-burning shuts down fat-burning while glucose is pouring in.

        Ed wrote on May 20th, 2011
  23. Dana, best quote of the week, “when are you going beeratarian” great point and background about sugar being poison.

    Luke wrote on May 19th, 2011
  24. Brilliant post. Now how do I get everyone I know (and most of the people I don’t!) to read it?!!

    wilberfan wrote on May 19th, 2011
  25. 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.

    The Primalist wrote on May 19th, 2011
  26. 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.

    Bodhi wrote on May 19th, 2011
  27. 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?

    Susanne wrote on May 19th, 2011
    • can you get that in a supplement? If not, try eating more turkey.

      bbuddha wrote on May 19th, 2011
    • 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.

      Bill DeWitt wrote on May 22nd, 2011
  28. whats more important for muscle growth , stimulus to the muscle ,total calories or # of grams of carbs in the diet.

    alex wrote on May 19th, 2011
  29. 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.

    Jim wrote on May 19th, 2011
  30. 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.

    IvyBlue wrote on May 19th, 2011
  31. 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?

    rob wrote on May 19th, 2011
    • 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.

      Tim wrote on May 19th, 2011
      • I don’t think this guy is fueling his running with carbohydrates every hour.

        Lizzy wrote on May 20th, 2011
    • 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.


      j. Stanton wrote on May 19th, 2011
    • 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.

      mhikl wrote on February 4th, 2013
  32. 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!

    Roane wrote on May 19th, 2011
    • What you dropped?! Fat only or muscle and fat?!

      Kalin wrote on April 10th, 2012
  33. 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?

    Rachel wrote on May 19th, 2011
    • 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.

      Ann wrote on June 6th, 2012
    • My comment is on exact same phrase:
      “There is a downside, however: you can’t train long and hard day-in and day-out in the fat paradigm.”

      Doesn’t this guy train long and hard?

      Nadya wrote on April 12th, 2014
  34. Rachel – What was your diet like?

    Roane wrote on May 19th, 2011
    • 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%).

      Rachel wrote on May 19th, 2011
  35. 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>>>

    DAVE PARSONS wrote on May 19th, 2011
  36. 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.

    Rodney wrote on May 19th, 2011
    • 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.

      Primal Palate wrote on May 19th, 2011
  37. 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.

    Melie wrote on May 19th, 2011
  38. 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 :-)

    Primal Palate wrote on May 19th, 2011
  39. 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!

    Michelle Q wrote on May 19th, 2011
    • 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.

      Meg wrote on May 20th, 2011
  40. I agree…

    I just wanna know where leptin plays into all this…

    Mallory wrote on May 19th, 2011

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