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

The Definitive Guide to the Primal Eating Plan

Food Scale

Do the Math

In my recent Context of Calories post, I explained how the different macronutrients we eat at each meal (fats, proteins, and carbohydrates) have different effects in the body. I suggested that, despite their raw calorie values, it’s far more important to get a lasting intuitive sense of how much of each macronutrient you need and when you need it (or not).

But how do you do that? How do you figure out the proper number of calories – and breakdown of fats, protein and carbs – to accomplish your fitness and health goals? To lose weight? Lose fat? Gain muscle? Maintain status quo? Run marathons?

In fact, most popular daily diets look at overall calories as the main factor in weight loss and weight gain. The age-old conservation of energy Conventional Wisdom says that “a calorie is a calorie.” From there most diet gurus generally prescribe some formulaic one-size-fits-all breakdown of fats, protein and carbs. A classically trained Registered Dietician will tell you that protein should be around 10-15% of calories, carbs should be 60% (and mostly from whole grains) and fat under 30%. This macronutrient breakdown stays the same regardless of how much weight you need to lose or what other goals you might have. Barry Sears has his 40/30/30 “Zone” diet. The USDA bases everything on a choice of between 2,000 and 2,500 calories a day. But, as I said earlier, it’s not that simple. Calories do have context.

The human body uses these macronutrients for a variety of different functions, some of which are structural and some of which are simply to provide energy – immediately or well into the future. Moreover, with regards to energy conservation or expenditure, the body acts as both an efficient fuel storage depot (and as a toxic “waist” site) as well as a potent generator of energy, depending largely on the hormonal signals it gets. It will store glycogen and/or fat and it will build muscle – or it will just as easily tear them all down and use them for fuel – based on input from you: what you eat, how much you eat, when you eat, what you’re doing before or after you eat – even what you’re thinking when you eat. Yet because your body always seeks to achieve homeostasis over time, the notion of you trying to zero in on a precise day-to-day or meal-to-meal eating plan is generally fruitless (yes, Charlotte, some fruit is allowed). The good news in all this is that falling off the wagon once or twice this week won’t have the immediate disastrous effect that you might imagine – as long as you can keep your average intake under control and understand how the various macronutrients function over time.

Which brings me to the crux of today’s discussion. Not only is it nearly impossible to accurately gauge your exact meal-to-meal calorie and macronutrient requirements, doing so will drive you crazy. In fact, to accurately figure your true structural and functional fuel needs (and hence to achieve your goals) it’s far more effective to look at a much larger span of time, like a few weeks, and aim for an “average” consumption. Then you can review that average daily intake over weeks or months and adjust accordingly. Below, I’ll give you a way to figure a “jumping off” point to start with, but remember, our genes are accustomed to the way our ancestors ate: intermittently, sporadically, sometimes in large quantities, and sometimes not at all for days. Their bodies figured out a way to maintain homeostasis and preserve lean tissue and good health through all this and so can we. Our genes want us to be lean and fit. It’s actually quite easy as long as we eat from the long list of Primal Blueprint healthy foods and try to avoid that other list of grain-laden, sugary, processed and otherwise unhealthy foods. Realistically, we also want to allow for the occasional party-splurge, a pre-planned (or accidental) intermittent fast, an over-the-top workout or even a week of laziness. Where most people get into trouble is in miscalculating their energy needs over extended periods of time – not day-to-day. They don’t see the average amount of carbs creeping upwards, or they figure they need x amount of calories, but don’t have a clue as to what kind of food those should be coming from.

I start with these four basic principles to guide my Primal Blueprint eating style:

1) 80% of your body composition will be determined by your diet. Yes, exercise is also important to health and to speed up fat-burning and muscle-building, but most of your results will come from how you eat. I’ll write more on this later, so just trust me on this one for now. Suffice to say, people who weigh a ton and exercise a ton, but eat a ton, still tend to weigh a ton. I think I’ll have that made into a t-shirt…

2) Lean Body Mass (LBM) is the key to life. I’ve said it many times on this site: lean mass (muscle and all the rest of you that is not fat) is directly correlated with longevity and excellent health. Rather than strive to “lose weight”, most people would be better off striving to lose only fat and to build or maintain muscle. Since other organs tend to function at a level that correlates to muscle mass, the more muscle you maintain throughout life, the more “organ reserve” you’ll have (i.e. the better the rest of you will work). Refer back to rule #1 and eat to build or maintain muscle.

3) Excess body fat is bad. Most human studies show that being significantly overweight increases your risk of nearly every disease (except osteoporosis – because ironically it responds to weight-bearing activities). Fat just doesn’t look that great either. See rule #1 and eat to keep body fat relatively low.

4) Excess insulin is bad. We’ve written about it here a lot. Chronic excess insulin may be even worse than excess sugar (and we know how bad that is). All animals produce insulin, but within any species, those that produce less insulin live longer than those who produce a lot. Eat to keep insulin low.

Here is how I use these principles to guide my individual macronutrient intake:


Raw Steak

Protein takes priority. If there is ample glycogen (stored glucose) and the body is getting the rest of its energy efficiently from fats, protein will always go first towards repair or building cells or enzymes. In that context, it hardly seems fair to assign it a “burn rate” of 4 calories per gram. It’s like saying the 2×4 studs that support the walls of your house can burn nicely if you run out of firewood. They will, but I prefer to burn other fuel first. At a minimum you need .5 grams of protein per pound of lean mass/per day on average to maintain your “structure”. If you are moderately active you need .7 or .8, and if you are an active athlete you need as much as 1 gram of protein per pound of lean mass. That’s at a minimum, but it’s on a daily average. So a 155 lb moderately active woman who has 25% body fat (and thus) has 116 lb of lean body mass needs 93 grams of protein on average per day (116 x .8). If she gets 60 or 80 some days and 110 on others, she’ll still be in a healthy average range. And even if she exceeds the 110, it’s no problem if she’s eating low carb because the excess protein will convert to glucose, which will reduce her effective carbohydrate needs (see below). At 4 calories per gram, that’s between 320 and 440 calories per day in protein. It’s not that much.



If you’ve forgotten everything you ever learned in biology, just remember this and “own” it: Carbohydrate drives insulin drives fat (Cahill 1965, and Taubes 2007). The idea in the PB is to limit your carbs to only those you need to provide glucose for the brain and for some reasonable amount (certainly less than an hour) of occasional anaerobic exercise. And the truth is, you don’t even need glucose to fuel the brain. Ketones from a very-low carb diet work extremely efficiently at that task. Either way, ideally, we would like most of our daily energy to come from dietary or stored fats. Typically, (if you are at an ideal body composition now) I use a rule of thumb that 100-150 grams of carbohydrate per day is plenty to keep you out of ketosis (and ketosis is NOT a bad thing) but away from storing the excess as fat if you are the least bit active. Don’t forget that your body can make up to 200 grams of glycogen from fats and protein every day, too. On the other hand, if you are looking to lose body fat, keeping carbs to under 80 grams per day will help immensely in lowering insulin and taking fat out of storage. On the other other hand, if you are insistent on training hard for long periods of time, you would add more carbs (say, 100 per day extra for every extra hour you train hard). It becomes a matter of doing the math and experimenting with the results.

Ironically, it’s tough to exceed 100 grams of carbs even if you eat tons of colorful vegetables – as long as you eat like our ancestors and consume no grains, no sugars and few starchy vegetables (potatoes, yams, beets, legumes, etc). Even if you eat a ton of vegetables AND a fair amount of fruit, you’ll be hard pressed to exceed 150 grams of carbs on average per day. Our remote ancestors couldn’t average 150 grams of carbs a day if they tried, yet they had plenty of energy and maintained their lean mass. At 4 calories per gram that’s only between 400 and 600 calories per day. Add that in to the protein above and our sample girl is barely at 1,000 calories on the high end. So where does the rest of the fuel come from?


Olive Oil

Learn to love them. They are the fuel of choice and should become the balance of your Primal Blueprint diet. Fats have little or no impact on insulin and, as a result, promote the burning of both dietary and stored (adipose) fat as fuel. Think about this: if protein and carbs stay fairly constant (and carbs stay under 150), you can use fat as the major energy variable in your diet. Feeling like you need more fuel (and you’ve already covered your bases with protein and carbs)? Reach for something with fat. Nuts, avocados, coconut, eggs, butter, olive oil, fish, chicken, lamb, beef, the list is a long one. 100 grams of fats per day would only add 900 calories to our girl’s daily average, putting her at between 1620 and 1940 calories a day. Even if she averages somewhere between 1400 and 2200 calories per day over a few weeks, as long as she pays attention to protein and carbs, her body composition will shift to lower body fat and more desirable lean mass. If she decides to do some walking, a few brief intense weight sessions and a sprint day here and there, that process would accelerate greatly. If she gets to a point where she’s content with her body fat, she can even add in a little more fat to provide energy that she previously got from her stored fat.

The main thing I’ve figured out from eating this way for years is that I don’t need nearly as many calories to maintain health, mass, and body fat as I once thought I did – or as the Conventional Wisdom says I do. I eat 600-1000 calories per day less than when I ate a carbohydrate-based diet, yet I maintain slightly lower body fat and slightly higher muscle mass on even less training. Remember: 80% of body composition is determined by diet. The best part is that I don’t ever feel hungry because I base my eating on exactly what my 10,000-year-old genes want me to eat.

For a look at my upcoming book, The Primal Blueprint, click here. I’ve included a sneak peek at the jacket artwork, a PDF of the table of contents and full chapter summaries.

Further Reading:

Definitive Guides to:

The Primal Blueprint




Insulin, Blood Sugar and Type 2 Diabetes

Stress, Cortisol and the Adrenals

Prefer listening to reading? Get an audio recording of this blog post, and subscribe to the Primal Blueprint Podcast on iTunes for instant access to all past, present and future episodes here.

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. yes thankyou Klamolsch! I googled and searched high and low for a reason why I couldn’t sleep without the carbs and couldn’t find anything…so thanks for explaining that. I thought I would just never be able to do the low carb thang..

    I agree totally about the importance of sleep! I have issues sleeping as it is..body is so darn sensitive to everything and sometimes I go days struggling to fall asleep due to stress, change of routine, or even accidentally eating sugar! One crumb of sugar or anything processed and I’m up all night! Ridiculous! I am so envious of people who can fall asleep anywhere, anytime.
    I am going to do as you are .. slowly begin dropping my carbs. Sort of like Atkins backwards eh :)

    Heather wrote on February 10th, 2010
    • I used to not sleep at all. I take a calcium/magnesium/zinc capsule from solaray and it works wonders.

      MR! Stoner2udude wrote on September 27th, 2011
  2. What do we do if we can only eat about 800 calories a day or we gain weight? Water weight is poundage just the same. I was on Atkins, loved it, but my setpoint is now higher then it should be, possibly because of starvation mode or something. Now i am screwed…

    DBeeeee wrote on February 22nd, 2010
  3. To be perfectly honest though I don’t really count too many of anything except for protein. I do this b/c it’s simpler and I just don’t have the time. I work a lot, have a young family and am always on the run. I still take time to relax, workout and get close to right amount of sleep. Average between 6.5-8 hours per night.

    I eat very healthy with lots of veggies, good protein (probably 150-180 g per day form various sources), nuts, seeds and have basically cut out dairy and grain products. I do have the occasionally piece of garlic toast though. no more cold cereal, oatmeal, and fruits. I only eat fruits with a very high nutritional value.

    Matt Forrester wrote on March 18th, 2010
  4. I am interested in trying this method to reduce my bodyfat percentage from 25-26% to 19-20%. I get close, start to see some abs, and I squish up again. My question is… I know you discourage crazy intense exercise for long periods of time. I teach dance and I love it. It is extremely intense (I try to make it HIIT and take 45 second breaks every 2 minutes or so) and I”m soaking afterwards. I do this 4-5 times per week and I lift heavy weights 3 times a week. Do you think I can get away with the intenseness (intensity?) of my cardio if I eat enough protein?

    e. wrote on April 2nd, 2010
  5. I definitely need help.

    But here’s the thing: I can’t eat meat. I read Peter Singer’s “Animal Liberation” 25 years ago and haven’t eaten meat since. I know that it’s morally wrong to cause suffering to sentient beings (who experiences suffering just as acutely as we do) if we can possibly avoid causing that suffering.

    So what vegetable-based meat substitutes do you recommend to vegetarians?

    victoria wrote on April 6th, 2010
  6. I just have a few questions. Is your program based on net carbs? Also, I eat this sprouted grain bread that is only one net carb. Is that ok to eat? I even have low carb pitas. I was just wondering what your take is on this.

    Melissa wrote on April 10th, 2010
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    zogmailia wrote on April 22nd, 2010
  8. Thanks Mark. Do you have a simple “do not eat these foods” list. I started to type this up as I want to leave it with my cook so she knows what not to use. I’ve been following protein power / eades diet for a while now but wanting to get a little more primal…. if you have a list to ensure my kitchen stays primal too that would be great! I have switched to organic free range eggs and the difference is amazing!

    Paul wrote on April 23rd, 2010
  9. I love this article…thank you for all the info. It has cleared up a few things for me regarding carb intake.

    Currently i find it very difficult to maintain muscle mass when i reduce my carb intake?

    Rob wrote on May 17th, 2010
  10. A lot of Eastern Block Olympic lifters would get 50% of their calories from fat. Their chubby American competitors are high carb diets instead. Guess who won all the medals back then?

    nathan wrote on June 1st, 2010
  11. Any advice on quitting coffee/caffeine?

    I have noticed that even a small amount interferes with blood sugar.

    Thank you for your great site!

    Mary wrote on July 4th, 2010
  12. Mark,

    My girlfriend has IBS and is extremely sensitive to vegetables. Basically, when she eats most kinds of vegetables, her stomach balloons to the point where she looks about 8 months pregnant. What are your thoughts on this and IBS in general?

    Brett wrote on July 7th, 2010
  13. Mark,
    I am new to your plan. I am Type 2 Diabetic, sit behind a desk all day Monday thru Thursday and only get out early mornings (sometimes) to walk at fitness center or I go hiking with a friend at a local nature park. I weight currently 341 and would like to get down to 180. I also take High Blood PRessure meds (2 of them), diabetes med. My nutritionist told me to eat btwn 50-60 grabs carbs per meal 3 times a day. I have tried different things to lose weight, but everytime I come down to 300, my body decides to go back up. I NEED HELP!

    Dirk Baeuerle wrote on August 10th, 2010
  14. Mark,

    I just purchased your Primal Blueprint book, and just started reading it. Some things are a little confusing to me. im a plan and simple kinda guy. Like to take the guess work outta things. My question is are there any list out there to tell us what would be the best meats, vegs and fruits to eat?

    John Mills wrote on August 15th, 2010
  15. Later in the book, Mark highlights some of the best plants and fruits to eat, ones that give the most nutrient bang for the least carb buck. He also explains in full detail what meat labels mean, and how to make your purchasing choices based off them.

    Cameron wrote on August 15th, 2010
  16. I did not realize it but after reading what the Primal Blueprint diet is, I have been doing that diet for at least the last 5 months. I have been dieting since January and I have lost 43 pounds. I started with about 100-200 grams of carbs a day and gradually lowered that amount. Now I am at 20-40 grams of carbs a day and the weight loss is moving quicker. I eat lots of protein, a good amount of vegetables and I snack on peanuts and hard boiled eggs. I exercise 2-2.5 hours a day (2-3 aerobic classes). I am in the last 10-15 pounds of my diet. I started with cellulite in my legs and fat rolls on my stomach. Now I have no cellulite on my legs and no fat rolls on my stomach and my skin is very toned. I went from 203 to 160 pounds and transformed my body and I know the exercise and eating right had alot to do with it.

    Toni wrote on August 27th, 2010
    • Uh, I’m jealous. I wish my cellulite was gone.

      Kate wrote on September 7th, 2010

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