The Hungry Brain

[liquidstayce]

The Hungry Brain,
9/21/2004

Are modern chronic diseases - obesity, hypertension, heart disease and diabetes - the result of modern diets that are so radically different from the diet of prehistoric hunter-gatherers?


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At least this is what Doctors Eaton and Konner wrote in their article "Paleolithic Nutrition," published by the New England Journal of Medicine in 1985 and resulted in one of the dieting bestsellers, the "Neanderthin" by Ray Audette. They concluded that the modern chronic diseases — obesity, hypertension, heart disease and diabetes, are the result of modern diets that are so radically different from the diet of prehistoric hunter-gatherers.

Now, however, our knowledge about the evolution of human nutrition has advanced and we know that there was no single, Paleolithic diet but was a much more flexible eating pattern resulted in a "omnivorous" nutrition make up. Studies of modern human populations traditionally living in "prehistoric" environments show that we humans are able to use a wide variety of diets.

It's the energy imbalance that matters
The industrial world, where calorie-packed foods are readily available, now faces diet-related health problems resulting not from deviations from a specific diet but from a lack of energy balance: between the huge energy amounts readily available and the little energy we really need to sustain our comfortable lives. But there's also one less known reason why we are strange primates: the brain's nutrition needs.

The brain of a modern human being is 16 times hungrier than the muscles.
What is extraordinary about our large brain is that every gram of it consumes 16 times as much calories as 1 gram of muscles. AND we use a much greater *part* of our energy budget to feed our hungry brains: up to 25 percent of our energy needs -- compare it with the 10 % in other primates, and 3 to 5 % in other mammals. As a general rule, animals with bigger brains feed on calorie-denser foods, and we humans developed this strategy to the extreme.

Contemporary hunter-gatherers living a prehistorical life style get up to 60 % of their energy from energy-dense animal products. In free-living chimps, it's just 5 to 7%. In the same volume, animal foods bring in more calories than plant foods. What's wrong with this picture is that our eating behavior reflects earlier stages of hominid evolution: we control our eating still judging our meals by their volumes rather than anything else.

The practical part.
We can use this fact about our eating behavior, to construct a diet that works for us, and decrease our calorie density. Studies showed that a simple trick like drinking a glass of water before meals help us feel fuller, sooner and on fewer calories. When your grandma told you to eat your soup she was right. Soups, due to the high water content -- vegetable soups, also due to higher fiber content -- result in fewer calories eaten during the entire meal.

When the Hellers (The Carbohydrate Addict's Diet) advised to fight stalled weight loss with a big salad before meals, they were right, for the same reason. The nutrition consequences. It's all good, but there's another aspect of feeding our hungry brain. Not only is it hungrier for calories, it's also hungrier for nutrients than any other organ.