bell-curveWithin the ancestral health community, one of the longest standing debates is that over the appropriate macronutrient levels of protein, fat, and carbohydrate which people should eat. Riding the wave of the ancestral movement, has been an amelioration of dietary fats. I wouldn’t say the mainstream has really caught on yet, but the tide is certainly shifting.

Within the paleo community, there is almost the opposite going on, where carbohydrates are shifting somewhere between poison and panacea. Thought-leaders like Gary Taubes and Dr. Robert Lustig, have painted a picture where carbohydrate, probably more so sugar, when eaten to excess can cause severe health issues (type 2 diabetes, heart disease, obesity, etc). On the other hand, a noticeably increasing cadre of bloggers and researchers are doing a 180 degree turn, and placing more emphasis on issues related to carbohydrate deficiency, such as thyroid health.

Caught in the crossfire, are of course the many people trying to improve their health and lives by eating better. What I have observed (through blog comments, and sites like, is a not insignificant amount of people who eat diets which hover around near total exclusion of either carbs or fats. You have the 80-10-10′s (ratio of carbs to protein to fat), and then there are the neo-caveman carnivores, emulating a supposed Inuit diet or eating just meat and fat.

Are these types of diets advisable? Are they even appropriate based on what we know of human evolution and physiology? For the second question, each camp will most assuredly and emphatically say, “yes”. In truth, one can easily present various pieces of evidence in a certain light, and come out looking correct. From a broad perspective though, I believe that less extreme diets will probably be appropriate for a larger selection of people, and are more likely to reside within the comfort zone of your own particular genetics.

Why? Well for one, I think that ignorance of cultural behaviors and even of hominid evolution and physiology has lead people to believe in “facts” that are either not entirely accurate, or are somewhat distorted.

inuit-dietFor instance, it is commonly believe that the Inuit (poster-child for many low-carb devotees) eat almost no carbohydrate-based food, living almost entirely on meat and animal fat. Their relatively low incidence of degenerative diseases (before westernization) is then used as one leg of a argument supporting zero-carb diets.

The whole truth is that the Inuit ate a fair amount of plant food (when available during the warmer months) and even took to eat the fermented remains of food from the stomachs of caribou. There is a fascinating book called “Plants That We Eat” that explores this aspect of Inuit culture, and Melissa McEwen has done a great review of it.

One phrase that is commonly repeated, is the concept that “there are no essential carbohydrates.” This stems from the fact that the human body can produce glucose through a process called gluconeogenesis. This allows the body to maintain blood-sugar levels during periods of ketosis, low or even zero carbohydrate consumption. However, it does not follow, from a logical sense, that just because carbohydrates aren’t essential for maintaining life, that carbohydrates are not still useful, or even necessary for maintaining optimal health. Some people eating low carb diets and exercising a lot are susceptible to a condition of thyroid dysregulation called “euthyroid sick syndrome”. Anthony Colpo has written extensively about this topic, especially as someone who has compared low carb and higher carb diets during training.

From an evolution and physiological standpoint, I think that the fact that humans evolved to have saliva glands which secrete amylase, an enzyme that catalyses the breakdown of starch into sugars, provides at least cursory evidence that carbohydrate consumption can be useful.

On the opposite end of bell curve, you have the low or no fat folks. While less of these in the ancestral health community, there are probably more in vegetarian or vegan groups. Among these people, the idea persists that dietary fat is detrimental to health, and by and large is promulgated by nutritional plans from doctors like Dean Ornish. And won can’t forget that the U.S. government has continued to insist that fat is bad, leading to the platforms of organizations like the American Dietetic Association to back their play.

From an overview, diets that are extremely low fat like 80-10-10, commonly used by frugivores, are backed up with arguments that humans closest or direct ancestors are and were primarily herbivores or frugivores, subsisting largely on plants and fruit. This is certainly true, to an extent, though it’s often conveniently ignored that chimpanzees regularly consume meat in the form of other monkeys.

primate-evolutionStill, the problem remains that chimpanzees and other high order primates are our closest living relatives. When they eat fruit all the time, it makes a clear argument that perhaps we should eat mostly fruit, and maybe little fat. But the thing is, they are just our closest living relatives.

There are still millions of years of evolution that happened between us since hominids branched off, and the adaptive changes have only sped up since the genus homo started migrating all over the world. It’s hard to say with absolute certainly what our actual closest relatives ate, since they’re now extinct, but one reason to suspect it was similar to the normal omnivorous diet is that they ended up competing with other human ancestors for food, and lost.

As it turns out, the evolution of the colon in primates and hominids might shed an interesting light in how the diets of these various species is significantly different (and why orangutan diets aren’t applicable to humans). On the evolutionary march, the size of the colon and small intestines changed in accordance to the eating patterns of the animals in question. The colon has become progressively smaller by ratio of total intestine and body mass, from orangutan, to chimp, to humans. This correlates well to the observed prevalence of omnivorous behavior, with orangutans and gorillas being almost completely vegetarian, while chimps eat some meat on occasion, and humans eating meat frequently.

This bears credence because vegetable matter and fiber is primarily digested in the colon, or large intestines. The more vegetable matter that is consumed, the larger the colon would need to be to provide adequate fermentation and nutrient absorption.  The fact that humans have substantial small intestines, thus provides excellent evidence that we are not engineered to subsist on plant food. Melissa McEwen provided an excellent talk on this concept at the 2011 Ancestral Health Symposium, it was actually one of my favorites.

Ultimately, it should be recognized, that while we might not all be special precious snowflakes, there is bound to be subtle yet important differences in each of our genetic codes. The special adaptations that allowed various human populations and cultures to live and eat in a certain way, do not necessarily translate over perfectly to those of us outside that group, or separated by time and location. The ethno-geographical distribution of lactose intolerance throughout the world should be a clear indication of that.

For ideal and optimal health concerns, I suspect that the most prudent nutritional course would be one that steers towards the middle of the bell curve. The further you stray towards the edges, the more likely that you will encounter detrimental or less-optimal effects towards your health or performance. There may be valid reasons to go either route down the extremes (diabetes, morals, etc.) but it would be advisable to evaluate these changes from the perspective that they are not necessarily ideal, and consider the possibility that they aren’t optimal health-wise for everyone.

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11 Responses to Chasing Extremes: Are Severely Proportioned Macronutrient Ratios Appropriate?

  1. Phillip Upton says:

    I think that any discussion of macronutrient ratios in the absence of activity levels is missing something.

    For example, I’m very comfortable with an even 33/33/33 split (weight not calories) for macronutrients on days that I lift weights.

    That also works OK if I keep my non-weight lifting exercise under an hour.

    But if I hop on the bike for a four hour ride with friends, you can bet that I’m going to take in quite a few more carbs.

    An easy but long base building ride will usually skew to the fat side. (I like to eat coconut oil/flakes on these rides, if at all.)

    If I’m not planning on any exercise I usually drop the carbs almost completely.

    It is almost like the Perfect Health Diet in that I set a base level of protein and fat. Then I modify fat and carbs to match the amount AND type of activity.

    And, I “earn” my carbs. (Which is totally different from shunning them. I actually think we *need* carbs. But I think that we need them because we also need to be active.)

    In the end, I think context matters.

  2. wilberfan says:

    “Caught in the crossfire, are of course the many people trying to improve their health and lives by eating better. ”

    Boy, howdy. Thanks for weighing-in on this… I get quite confused in the back-and-forth of the Paleosphere.

  3. David Csonka says:

    Quoting – ‘And, I “earn” my carbs. (Which is totally different from shunning them. I actually think we *need* carbs. But I think that we need them because we also need to be active.)’

    I like that stance.

  4. mallory says:

    i think earning carbs is a bad representation, and moreso for females. you dont ‘earn’ energy, you give it to your body to use and nourish yourself. this ‘earning business’ around carbs is why i hate paleo/primal and the whole blogsphere it entails. if you must ‘earn’ a strawberry, then youre also ‘shunning’ the same strawberry. that is just way to OCD with food, people do not need to flippin stress about real food. if we would just listen to our body’s and eat we’d be much better off. needs change everyday every hour, every week and ‘exercise’ to ‘earn’ carbs places such a small roll in that i hate seeing them demonized unless you ass to the grass squat…

    • David Csonka says:

      I get what you’re saying, and I’m certainly opposed to increasing the already out-of-control levels of food obsession in our society.

      But, I think one of the problems that has to be recognized is general lack of physicality that pervades modern western cultures. For me, the idea of “earning it” is more about bringing diet *and* fitness into better alignment with our bodies’ programming.

      From a different perspective though, research has shown that people enjoy their meals more when more effort (whether through cooking, or physical effort to acquire) is expended to get it. I think this can be applied on many levels.

      And finally, I feel that our body utilizes or apportions the energy from our food more appropriately, when eaten after a workout, as opposed to any other time.

      For these reasons, I think that the idea of “earning” our meals can be appropriate, though not to the extent of reinforcing existing food-phobias, or issues, etc.

    • Kelly B says:

      Why “moreso for females”? I’m female, and I love the “earning carbs” concept. What am I missing here?

    • Phillip Upton says:

      I get what you are saying. And I see how that phrase could be a trigger phrase. And, I agree with David that we should not be increasing food obsession.

      But I do want to address one thing. Context matters.

      you dont ‘earn’ energy, you give it to your body to use and nourish yourself

      I wasn’t talking about energy, I was talking about carbs.

      Your body can use protein and fat for energy, in addition to carbs. I believe that fat is the bodies preferred/optimal energy source. (that or someone screwed up big time by designing us to store extra energy as fat)

      The thing to remember is that the minimum required dose of carbs is zero. You don’t need to eat carbs at all if you aren’t active because our bodies can make some glycogen without eating carbs.

      And the amount of glycogen your body can make aligns quite nicely with the amount of glycogen that your body needs to survive. The result is: you don’t need to eat carbs.

      But, sometimes it is nice to do more than just survive.

      Context matters.

      For the most part your body will do one of two things with ingested carbs: convert it to glycogen or triglycerides.

      And, you only have the ability to store a limited amount of glycogen. So, if you take in more carbs than can be stored as glycogen, it will be converted to triglycerides and stored as fat.

      That is the context of the phrase “earn your carbs”. The idea is to perform activities of sufficient intensity and duration so that you have the ability to store additional glycogen. In other words, don’t eat so many carbs that you have no option other than storing them as fat.

      (Again, context matters. If you are running at a calorie deficit then any triglycerides that are produced from the carbs will be quickly used for energy. But, in the short term the body has to deal with the carbs somehow, or you will die.)

      Obviously, if you are actually trying to increase fat stores, then you don’t want to “earn your carbs”. And, that very well could be an issue for women who do need a certain level of fat for things to work optimally.

      So, context matters. If you are trying to reduce body fat, you want to “earn your carbs”. Heck, if you are trying to reduce body fat, you want to “earn your calories”. Period.

      More importantly (to me) the context of my use of the phrase “earn your carbs” was followed by the fact that I think people should be performing enough activity on a routine basis that carbs are needed.

      Which was actually the point I was trying to make: I think we need to eat carbs because I think we need to be so active that it becomes necessary.

      I don’t think health is just an issue of diet, but also activity. And I was trying to set what I believe is a minimum activity level: enough so that you have to eat carbs to replenish glycogen. (Remember that the body can make enough glycogen for a sedentary person.)

      BTW, the idea that we need a minimum activity level isn’t mine. Just the idea that it should be related to carb intake is.

      It seems that at low activity levels the body’s ability to regulate food intake breaks down and we consume more than we need.

      Check out the lower graph in figure 1. The sedentary people were eating as much as the active people. It should have been a relatively straight line but intake became “uncoupled” as activity decreased below the ‘clerks, III’ level.

      • David Csonka says:

        Great reply. “context matters” is so very true. Though one ironic thing here, is that with just about everyone who provides so sort of advice with respect to ancestral/evolutionary health and fitness – it always includes encouragement to stay active and to exercise. So, one would think that the carb consumption to support the recommended exercise would go hand in hand – based on that line of thinking.

  5. Great article!

    I agree that a ‘middle of the road’ approach is likely best for most people, but I have found that it’s too difficult to maintain a sufficiently low dietary food reward value (and therefore control weight) without keeping carbohydrates below about 100g/day.

    Other approaches to food reward control also work, but are much harder to implement in the real world- especially if you’re traveling or eating at restaurants.

    The only way I can eat higher amounts of carbs without gaining weight is if they’re very bland and plain to the point of being nearly unpalatable (such as a plain microwaved potato served with canned sardines). It’s difficult to do and not very enjoyable.

    • David Csonka says:

      I’ve had a similar experience. Home-made mashed potatoes and ground beef, eating a giant bowl of that on an extended basis (with intermittent fasting) and I was still able to lose a decent amount of fat. Granted I wasn’t overweight to begin with, but people really noticed how much thinner I was becoming, and my pants were so loose.

    • Phillip Upton says:

      Hm, I thought I was the only one that had potatoes and sardines.

      And I mean and… I mix them together.

      Oddly delicious, IMHO.

      (P.S. Is there a way to preview a reply? I noticed a few grammatical errors in my last one.)