Humans have eaten very high-carbohydrate foods (especially high intakes of grains) for only a short time in their overall development. For many thousands of years’ humans survived as hunter-gatherers, eating predominantly meats, eggs, fish, birds, leaves, nuts, seeds, and smaller amounts of grains and legumes.
It's only in the past several thousand (an evolutionary ‘blink of the eye’) that we have shifted to a food environment in which grains dominate our food supply. It is even more recently that we began to eat the vast quantity of highly processed and refined food that make up the bulk of the modern diet.
We tend to think that having an abundant supply of food from grains and other staples is a good thing for health but when we shifted to an agricultural food supply, from a hunter-gatherer one, people’s height decreased and health suffered.(1)
A diet based on few staple crops provides less variety of nutrients than one based on hunted and foraged foods. This had the effect of leaving people less nourished and made them more susceptible to disease.
By looking at available research on hunter-gatherer peoples, we can see some of the best evidence for not only how humans have eaten over the course of our progression as a species but also how this affects health.
Until relatively recently hunter-gatherer groups have subsisted healthily with a significant absence of metabolic disorders like diabetes and insulin resistance on a lower-carbohydrate diet. The Inuit for example, have by necessity utilised a low-carbohydrate diet for millennia,(2) and Aboriginal diets in Australia are low in carbohydrate and promote the maintenance of lean body weights and minimised insulin resistance. When Aboriginals transition to a modern western diet that is high in carbohydrate and refined foods, the incidence of metabolic disorders, obesity and diabetes rise markedly but when they revert to a traditional hunter-gatherer lifestyle it causes ‘striking improvements’ in health.(3)
It should be noted, that there is considerable variation in the macronutrient content of hunter-gatherer diets. 229 hunter-gatherer diets have been analysed, finding a large variation in carbohydrate intake, ranging from approximately 3% to 50% of daily calories. This variation is related to where these peoples live. In other words, if there have been lots of carb foods around, you’re more likely to eat them…and to have adapted to be able to eat them.
Despite the wide variation in carb intake the authors of this study noted that the carb intake of all of the hunter-gatherer people studies is lower than the current dietary recommendations.(4) So, the recommended minimum amount of carbohydrate for modern humans is higher than the intakes of any of the hunter-gatherer populations studied.
In contrast to our high-carb dietary guidelines for health, most people have thrived traditionally on diets consisting of between 1/5th and 1/3rd carbohydrate, with higher amounts only found in extremely fertile, tropical regions and extreme low-carb diets common in extremely cold areas that lack an abundance of carbohydrate foods.
Lower-carbohydrate diets have shown great promise for the treatment of obesity, diabetes and metabolic syndrome, neurological disorders, cancer, and have potential applications for heart disease prevention and improve some aspects of sports performance.(5, 6) Likewise, other interventions like exogenous ketones, and short and medium chain triglyceride supplements, offer a tantalising opportunity to ‘hack’ the body and mind for greater performance, both mental and physical, and improve compliance with any diet….whether low carb, or not.
It’s likely that the diet you were born to eat is lower in carbs than the one you’ve been told to eat but it's extraordinarily variable, with some people thriving on low-carb, and some on high-.
Overall the diet that works best is one that allows you to get enough nutrients, without too many calories. And so, typically, this is a diet that you can eat ad libitum without getting fat. And for many of us, that includes low-carb, with periodic intermittent fasting...
But more to come on that soon!
1. Mummert A, Esche E, Robinson J, Armelagos GJ. Stature and robusticity during the agricultural transition: evidence from the bioarchaeological record. Economics and human biology. 2011;9(3):284-301.
2. Sinclair HM. The Diet of Canadian Indians and Eskimos. Proceedings of the Nutrition Society. 1953;12(01):69-82.
3. O'Dea K. Westernisation, insulin resistance and diabetes in Australian aborigines. Med J Aust. 1991;155(4):258-64.
4. Ströhle A, Hahn A. Diets of modern hunter-gatherers vary substantially in their carbohydrate content depending on ecoenvironments: results from an ethnographic analysis. Nutrition Research.31(6):429-35.
5. Paoli A, Rubini A, Volek J, Grimaldi K. Beyond weight loss: a review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets. European journal of clinical nutrition. 2013;67(8):789-96.
6. Sumithran P, Proietto J. Ketogenic diets for weight loss: A review of their principles, safety and efficacy. Obesity Research & Clinical Practice. 2008;2(1):1-13.