When I first heard that “the Paleo Diet” is considered controversial, I was kind of surprised. As you’ll see here, to me, this approach to nutrition is obviously right. This said, I now realize that one should never be surprised by anything related to the concept of evolution being controversial. As I step back and look at concepts, trends, and intellectual areas of inquiry that relate to evolution, including evolutionary biology, evolutionary psychology, biological anthropology, genetics, sexual selection theory, natural selection, etc., I realize that controversy simply comes with the territory.
The Paleo Diet (see Cordain et al., 2005) is an approach to nutrition based on the principle of evolutionary mismatch, which is a basic principle of evolutionary psychology. Evolutionary mismatch is essentially the idea that when an organism finds itself in an environment that is mismatched from the ancestral environments that surrounded the ancestors of the organism during the evolution of that species, things can (and will) often go wrong.
Perhaps the clearest example of evolutionary mismatch in humans pertains to diet. Under ancestral conditions of human evolution – prior to the relatively recent advent of agriculture (approximately 10,000 years ago) – the following facts relevant to nutrition were true:
Under such conditions, a strong motivation to obtain high-fat and high-sugar foods would be adaptive – as such an adaptation would drive people to obtain such foods which would help put on then-needed fat cells. So a preference for the then-rare high-fat and high-sugar-content foods was selected and evolved. After all, such foods were adaptive – then …
In modern conditions, high-fat meats are, actually, much more common than lean meats – and much more easily accessible. We have to pay more money for lean meat than for meat that is high in fat! And foods that are loaded with processed sugars are also very accessible – and they often come in colorful packages (think M&Ms ...). These kinds of foods sell so well – ironically, precisely because they were rare under ancestral conditions – and food technologies have out-paced biological evolution – so we still have these nasty food preferences – or these then-adaptive food preferences.
How does this matter to the modern human condition? Here’s how: In post-agrarian, or modern, societies, death as a result of obesity, cardiovascular disease, or Type-II diabetes is much more common than it is in non-Westernized, or nomadic societies. This is because modern societies provide nutritional offerings that are completely out of line with ancestral food offerings.
Our evolved food preferences, coupled with our modern technologies (such as the ability to make Big Macs for less than $5), are part of an enormous evolutionary mismatch which bears strongly on the nature of modern human health.
To my mind, the paleo diet simply pertains to the idea of eating the kinds of foods that were available to our pre-agrarian ancestors (think fruits, cooked meats, fish, nuts … stuff that’s natural). Or, perhaps more simply, it pertains to avoiding unnatural, processed foods that would never have been available under ancestral conditions (think cupcakes, pasta, cheese, Cracker Jacks, etc.).
While specific versions of the paleo diet may over-emphasize some nutritional details, and there is always something to quibble about, when we zoom out and look at this idea from the broad evolutionarily informed perspective that I describe here, doesn’t it just make sense?
To add to this scaled-down version of the paleo diet (or we can call it the more generically worded evolutionarily informed approach to nutrition, if we prefer), here it is in three words: Avoid processed foods.
References and Further Reading
Cordain L, Eaton SB, Sebastian A, Mann N, Lindeberg S, Watkins BA, et al. Origins and evolution of the Western diet: health implications for the 21st century. Am J Clin Nutr (American Society for Nutrition). 2005a;81(2):341–54
Wolf, R. (2010). The Paleo Solution. Victory Belt Publishing.
This blog entry is part of a series of blogs titled Evolutionary Psychology and the Human Condition.