Food for Thought: The Evolution of Human Diet

Contributed by Esther Lee, Rina Lee, Jasmine Labarca, Heather Wang, Phoenix Phung, Enakshi Das

Did you ever wonder what our ancestors ate? I do! The Paleo diet, also known as the caveman diet, Stone Age diet, and hunter-gatherer diet, consists of foods that are assumed to have been available to our ancestors before the Agricultural Revolution began around 333 generations ago. Our ancestors mainly ate meat, fruits, and vegetables before agriculture was developed, but now the Western diet has expanded to include a high number of cereal-grains, milk products, sugar, sweeteners, separated fats and alcohols, which now make up around 70% of our diet (Cordain et al., 2005). These new food sources were made available by the Agricultural and Industrial Revolutions.

During prehistoric times, our ancestors ate raw, unprocessed foods, which require much more energy to digest. Nowadays, cooking, through the process of heating and pounding, breaks down the food, so food is not only easier, but also more efficient to digest (Gibbons 2015). This transition underlies the expensive tissue hypothesis (Suburu 2013), which links changes in diet to evolution of the human brain. The hypothesis is that the brain and gut tissue both require lots of energy, so as our brains became larger, the gut size became smaller. Cooking also allowed us to absorb more energy from food, further shrinking our gut, and allowing us to expand our brain. 

Some people think that the Paleo diet is healthier because it is what sustained our ancestors and it is what we are thus adapted to eat. Instead of getting calories from processed foods, “Paleo dieters” get their nutrients through meat and raw, unprocessed foods. Many critics argue that the Paleo diet lacks food variety and believe that humans are adapted to consuming a varieties of foods, including those available in our modern diet.

This presentation explores the pros and cons of the two diets:


However, neither diet may be optimal for all individuals because of variation in the human population. Each individual reacts differently to the foods offered in each diet (Wan). For example, based on your genes, you can have a sweeter tooth than your friends (Gibbons 2015). There will always be environmental and cultural factors that will determine which diet is the best for you!

For more information see:

Ameur, Adam et al. “Genetic Adaptation of Fatty-Acid Metabolism: A Human-Specific Haplotype Increasing the Biosynthesis of Long-Chain Omega-3 and Omega-6 Fatty Acids.” American Journal of Human Genetics 90.5 (2012):809-820

Boers, Inge, Frits AJ Muskiet, Evert Berkelaar, Erik Schut, Ria Penders, Karine Hoenderdos, Harry J. Wichers, and Miek C. Jong. 2014. Favourable Effects of Consuming Palaeolithic-type Diet on Characteristics of the Metabolic Syndrome: A Randomized Controlled Pilot-study. Lipids in Health and Disease 13:160.

Burger, J., M. Kirchner, B. Bramanti, W. Haak, and M.G. Thomas. “Absence of the Lactase-persistence-associated Allele in Early Neolithic Europeans.” Absence of the Lactase-persistence-associated Allele in Early Neolithic Europeans. N.p., 27 Dec. 2006. Web. 30 Nov. 2015.

Cordain, L., Eaton S.B., Sebastian A., Mann N., Lindeberg S., Watkins B., O’Keefe J., Brand-Miller J. 2005. “Origins and Evolution of the Western diet: health implications for the 21st century. The American Journal of Clinical Nutrition 81: 341-354.

Eaton, S.B., Cordain, L. 1997. Evolutionary Aspects of Diet: Old Genes, New Fuels: Nutritional Changes Since Agriculture. World Rev Nutr Diet 81: 26-37.

Eaton, Stanley Boyd, and Stanley Boyd Eaton Iii. “Paleolithic vs. Modern Diets – Selected Pathophysiological Implications.” European Journal of Nutrition 39.2 (2000): 67-70.

Frassetto, L. A., M. Schloetter, M. Mietus-Synder, R. C. Morris, and A. Sebastian. 2009. Metabolic and Physiologic Improvements from Consuming a Paleolithic, Hunter-gatherer Type Diet. European Journal of Clinical Nutrition Eur J Clin Nutr 63: 947-55.

Gibbons, Ann. “The Evolution of Diet.” National Geographic. N.p., n.d. Web. 30 Nov. 2015.

Jew, Stephanie, Suhad S. AbuMweis, and Peter J.H. Jones. 2009. Evolution of the Human Diet: Linking Our Ancestral Diet to Modern Functional Foods as a Means of Chronic Disease Prevention. Journal of Medicinal Food.

Klonoff, David. “The Beneficial Effects of a Paleolithic Diet on Type 2 Diabetes and Other Risk Factors for Cardiovascular Disease.” Journal of Diabetes Science and Technology 3.6 (2009): 1229-232. Web.

Kowalski, L. M., and J. Bujko. “Evaluation of Biological and Clinical Potential of Paleolithic     Diet.” Rocz Panstw Zakl Hig 63.1 (2012): 9-15. Pub Med. Web. 30 Nov. 2015.

Leonard, William R. “Food for Thought. Dietary Change Was a Driving Force in Human Evolution.” Scientific American (2003): n. pag. ResearchGate. Web. 30 Nov. 2015.

Martens, E., Lowe, E., Chiang, H., Pudlo, N., Wu M., McNulty N., Abbott, D., Henrissat, B., Gilbert, H., Bolam, D., Gordon, J. 2011. Recognition and Degradation of Plant Cell Wall Polysaccharides by Two Human Gut Symbionts. PLOS Biology 9.12.

Milton, Katharine. “The Critical Role Played by Animal Source Foods in Human (Homo) Evolution.” Journal of Nutrition 133:3893S-3897S.

O’dea, K. “Marked Improvement in Carbohydrate and Lipid Metabolism in Diabetic Australian Aborigines after Temporary Reversion to Traditional Lifestyle.” Diabetes 33.6 (1984): 596-603. PubMed. Web. 30 Nov. 2015.

Schaeffer, Juliann. “Evolutionary Eating — What We Can Learn From Our Primitive Past.” Today’s Dietitian 11.4 (2009): 36. Today’s Dietitian. Web. 30 Nov. 2015.

Simmons, A. L., J. J. Schlezinger, and B. E. Corkey. “What Are We Putting in Our Food That Is Making Us Fat? Food Additives, Contaminants, and Other Putative Contributors to Obesity.” Curr Obes Rep 3.2 (2014): 273-85. Print.

Suburu, Janel, Zhennan Gu, Haiqin Chen, Wei Chen, Wei Chen, Hao Zhang, and Young Q.Chen. Fatty Acid Metabolism: Implications For Diet, Genetic Variation, and Disease. Food Biosci (2013) 4: 1-12. .

Tarantino, G., Citro, V., Finelli, C. 2015.Hype or Reality: Should Patients with Metabolic Syndrome-related NAFLD Be on the Hunter-Gatherer (Paleo) Diet to Decrease Morbidity?. Journal of Gastrointestinal and Liver Diseases J Gastrointestin Liver Disease 24: 359-368.

Wan, Samantha. Evolution in the Processed Foods Industry: Exploring the Impact of the Health Foods Movement. N.p.: U of Southern California, n.d. Print.