Studies show that people eating “ancestral diets” maintain excellent health and low body fat. Some of these healthy societies have a high carbohydrate intake while others get the majority of their calories from fat. Typically, people living closer to equator have usually gotten more of their energy from carbohydrate, while fat is the major source of calories closer to the poles.
Low-carbohydrate diets typically lead to increased weight loss compared to low-fat diets, but the available literature suggests that food choices might be the most important factor, not necessarily the macronutrient ratio.
No obesity in “non-westernized” populations
Ancestral/paleolithic diets consist of meat, fish, fowl, eggs, vegetables, fruits, mushrooms and other foods available before the agricultural revolution. Sugar, flours and processed foods are absent, and the consumption of grains, legumes and dairy is limited. Differences in food availability among populations are huge, but obesity and chronic non-communicable disease are pretty much absent in all of the societies that have been studied.
Primitive cultures getting the majority of their calories from carbohydrates usually eat plenty of fruits, nuts, and root tubers and other vegetables. The Kitavan Islanders of Melanesia have access to an “abundance” of food, with 60-70 percent of their energy from carbohydrates. Saturated fat from coconut is also a big part of their diet. This macronutrient ratio strongly resembles that of a westernized diet, but obesity and disease are absent in this and other cultures with the same lifestyle.
However, people in other regions have been known to thrive on a high fat and/or high protein diet. Animal products are common food staples in these populations, and the fattest part of the animal is always eaten.
Physical activity, sun exposure and other environmental factors can further promote good health, but have been shown to only offer a degree of protection against obesity and disease. Some non-westernized populations engage in a minimal amount of physical activity and still maintain excellent health.
People living on ancestral diets quickly become obese and diseased when they begin to eat western foods, even if they maintain regular physical activity and sun exposure.
Ancestral diets in the modern world
Studies on western people switching to a paleolithic diet show very promising results. When test subjects are allowed to eat as much as they want from either a Paleo diet or other “healthy” diets like the Mediterranean diet, subjects on a Paleo diet experience significantly greater weight loss and other health benefits. People eating a paleolithic/ancestral diet usually experience better satiety, and therefore their energy intake is unconsciously reduced.
Individual needs will be important in determining food choices, and some people might benefit from a diet with increased consumption of fruits, nuts, and vegetables. High fat and/or protein diets can be a better fit for others. In general, non-westernized diets are lower in carbohydrates than modern diets, and obese individuals often benefit from reducing carbohydrates when trying to improve insulin- and leptin resistance. Choosing organic and wild produce is the preferred option when possible.
In general, both studies and observations suggest that inflammation, satiety, energy homeostasis, and hormone levels are all affected by what types of food we eat.
July 2012, Pages 175 – 189
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