The Paleo diet is one of the fastest-growing diet trends in America, and advocates believe the “ideal” diet is one based on the animals and plants humans ate as hunter-gatherers. Paleo proponents maintain that there is a mismatch between human genes, history, and the modern diet. They argue that people were healthier and happier before agriculture flooded human diets with "Neolithic" grains and sugar.i

"Grain Brain" and other bestselling books have sought to redeem the nutritional profile of animal carcass and convince people that high-carb diets promote unhealthy levels of brain and gut inflammation. Neurologist David Perlmutter asserts that bread is not just bad for the digestive system, but it also wreaks havoc on the mind.ii

“Modern grains are silently destroying your brain,” Perlmutter writes. “Basically, I am calling what is arguably our most beloved dietary staple a terrorist group.” There are hundreds of other medical professionals who claim to practice "evolutionary medicine."iii

In promoting red meat and rejecting grains, the paleo diet turns the food pyramid on its point. They challenge what nutritionists have been advocating for five decades - high-fiber, low-fat beans and whole grains should be part of a healthful diet.

Doctors know little about evolution, and it is very difficult to design a clinical trial based on historical diets. Paleolithic foods have been modified, and are no longer available in their original forms. There is scant evidence that the neo-paleo diet works as a weight management tool, and little support for the Paleo diet in the medical and nutritional literature.

Humans did not stop evolving 10,000 years ago or at any other point in time, and so human diet was never “ideal.” Evolution can work very quickly, and humans are not biologically identical to Paleolithic cave dwellers. Humans have lived in all kinds of places and we have adapted to all kinds of diets. And, archaeological evidence suggest most humans have been eating grains and legumes, and not that much meat, for milennia.iv

Paleo dieters care about their health, and advocates recommend eating organic, pastured, holistically grazed animal protein. But there is not near enough grazing land to produce sustainable animal carcass and eggs for seven billion people.

It is critical to understand that human health is inextricably bound to the health of Earth’s ecosystems. Humans are but one link in the web of life, and that web is being polluted and stretched to the breaking point by animal-based agriculture. Paleo advocates' view of ‘Let them eat steak’ is an unmitigated GHG disaster.

On the other hand, a European lifecycle assessment showed that replacing animal carcass with peas is more climate and environment friendly. The research group found that switching to plant-based protein sources aids in the reduction of global warming, eutrophication, acidification, and land use.v

i Eliza Barclay. 2013. "Was 2013 Really The Year Of The Paleo Diet?" NPR, The Salt. December 30.

ii Elizabeth Kolbert. 2014. "Stone Soup: How the Paleolithic life style got trendy." The New Yorker. July 28.

iii Eliza Barclay. 2012. "The Paleo Diet Moves From The Gym To The Doctor's Office." NPR, Shots. June 2.

iv Christina Warinner. 2013. "Debunking the paleo diet." TEDx. Talk in Norman, Oklahoma, on Feb 12.

v J. Davis, U. Sonesson, D. U. Baumgartner, and T. Nemecek. 2010. “Environmental impact of four meals with different protein sources: case studies in Spain and Sweden,” Food Research International, vol. 43, no. 7, pp. 1874–1884.