Back to the Roots, or Pass the Ketchup Please?

As happens with modern behaviors, the presumed ancestral human diet has been lifted up as a utopian ideal by which to live. The Paleo Diet (also Evolution Diet, NeanderThin) offers a way to return to our roots and reduce the risk of many current diet-related plagues – diabetes, high blood-pressure, and heart disease, to name a few. Proponents of these ancestral diets recommend removing from one’s diet foods only made possible with an agriculturalist practice – processed foods, wheat and other grains, etc. Instead, they recommend people eat fruits, nuts, and meat. Is this ancestral diet right for modern humans?

While many primates are frugivores, relying mainly on fruit for food, and other mammals are herbivores, carnivores, or omnivores, humans are most accurately diversivores – we not only eat a wide variety of foods, but we do so by design. Our digestive needs are such that we require meats to make some essential amino acids that our bodies cannot create; fruits and vegetables to provide us with necessary vitamins and minerals, etc. (Martin & Pilbeam, 1994). The agricultural diet, in its purest form, is not so far from these needs – this diet includes meat sources from cows, pigs, chicken, and a variety of other commonly slaughtered animals; grains; fruits and vegetables. Part of problem with agricultural eats is that modern foods mimic foods we were designed to eat but that were previously rare to come by. For example, with calories hard to find, we have evolved the craving for sugary and fatty foods so that we will bulk up on them when we do come across them. However, with sugars and fats far too common in agricultural societies, we end up with health problems.

Evolution is reputed for being a slow process – human ancestors didn’t just walk upright overnight. However, many lines of research now provide us with examples of much quicker heritable changes, such as that for lactose tolerance. People who come from places where cows have been domesticated for many hundreds of years possess the enzyme to digest lactose more often than those from places where cow domestication is more recent. That is why people from the Mediterranean can chow down on cheeses and yogurts, while friends from Asia may have to indulge less frequently. Agriculture as a common human practice is at least 11 thousand years old. Our bodies have kept up with lactose for 5-6,000 years, surely other changes have occurred since the advent of domestic corn and oats. We cannot view modern humans as stagnant – though evolution may move too slowly for us to notice in a few generations, our bodies (including minds) are changing as does our environment.

Finally, looking to our more traditional-living relatives, you aren’t going to see much obesity because the lifestyle won’t allow it. When is the last time you made a 20 mile hunting trip on foot? Undertook the back-breaking work of gathering roots and collecting water? Chances are never, as is true for most modern Americans. If many of us want physical exercise, we have to find it in a gym or a track. Sitting at a desk all day is a poor replication for our ancestral lifestyle. If you want to eat like our ancestors, you might also consider the demanding physical lifestyles in which they embarked. The calories in the actual foods aren’t going to vary that much, it’s the amount of calories we consume v. expend. We can’t all expect to join the Michael Phelps meal plan (~10,000 calories a day) without swimming laps like it’s a full time job.

Let me be honest – if you set before me a plate of organic fruits and veggies, or highly processed Twinkies and Ho-Hos, the choice will not be difficult – I will gorge on the mangoes. But if you want my advice on the Caveman’s diet, I’d say – walk the walk, or embrace moderate consumption of domesticated goodies. The problem isn’t agriculture, it is processed food and over-consumption, coupled with an unnatural amount of physical movement.

Further Reading:

Audette, R., Gilchrist, T., Audette, R. V., Eades, M. R. (2000). NeanderThin: Eat like a caveman to achieve a lean, strong, healthy body. St. Martin’s Paperbacks.

Cordain, L. (2002). The Paleo Diet: Lose weight and get healthy by eating the food you were designed to eat. Wiley.

Martin, R. D., & Pilbeam, D. R. (1994). The Cambridge encyclopedia of human evolution. Cambridge, UK: Cambridge University Press.

Morse, J. (2008). The Evolution Diet: What and how we were designed to eat (second edition). Code Publishing.

Simoons, F. J. (1969). Primary adult lactose intolerance and the milking habit: A problem in biological and cultural interrelations. Digestive Diseases and Sciences, 14(12), 8190836.