I suspect that many of you may not know that in December of 2013, I retired from Colorado State University (CSU) after 32 years of service that began in the fall semester of 1981 when I was a rookie professor, straight out of graduate school. At that early point in my career, the Paleo Diet concept was virtually unknown to the world, and for me this life changing idea would still lie six full years in the future. I remember the moment distinctly in the spring of 1987 when “I got it.”
I was thumbing through the CSU student newspaper when I came upon a student reporter’s editorial about a scientific paper on Stone Age diets that had been published two years earlier1 in the prestigious New England Journal of Medicine. The student reporter’s coverage of this scientific article piqued my interest, and I promptly walked down to the CSU library and Xeroxed this piece, took it home and read it – never realizing at the time, that this radical idea would guide me down a research track that focused my lifelong career interests upon the evolutionary basis for diet and health. In 1987, I had no idea that this revolutionary concept would forever change the way people would think about diet and health and eventually would become a worldwide diet/health movement known as The Paleo Diet, a term I coined in 2002 with the publication of my first book.
As this ground breaking idea turned into my lifelong passion, I realized that Darwin’s fundamental concept (evolution via natural selection) provided an organizational template, not just for all life processes on earth, but also for all organisms’ nutritional requirements – including our own. It became apparent to me that contemporary human dietary requirements were created by the same Darwinian process (evolution via natural selection) that has shaped all life on earth.
Further, I realized that to understand the optimal modern human diet, it was absolutely essential to understand the diets of our ancestors living in their native environment. And the native human environment is one of a hunter gatherer consuming wild plant and animal foods. So, as Boyd Eaton pointed out so many years ago,1 for us to understand the elements of a healthy contemporary diet, we must intimately understand our ancestral diet before it was adulterated with Neolithic, industrial and technological era foods.
This Paleo Diet concept is a magnificent and revolutionary idea, but as with almost everything in our 21st century world, the devil lies in the details. How can we really know the types of foods and food groups our hunter gatherer ancestors ate? And how can we know how the nutritional characteristics of their diets significantly differed from our own? Together with scientists from around the world, I have written extensively about these concepts in the past two decades.2-32 My research group and I have compiled the diets of 229 hunter gatherer societies6 studied in the ethnographic literature. We have even assembled the 13 known quantitative nutritional studies of hunter gatherers.11
The table below shows hunter gatherer nutritional data which I have never published in the scientific literature. This information comes from a 1948 study of Australian Aborigines prior to their westernization in a remote area of Northern Australia called Arnhem Land.33 As a prelude to the tabular information below examining the food choices of these four groups of foragers, I want to give you a blow-by-blow description of how Australian hunter gatherers prepared and ate a large animal kill. This passage below comes directly from the scientists and anthropologists who lived with and observed some of the earth’s last remaining hunter gatherers as they killed and ate a wallaby (a medium sized marsupial found in Australia).
Table 1. A Quantitative Description of Foods Consumed by four Australian Aborigine Populations before Westernization.
A large fire was made in a depression in the sand and stones and shells were heated. Small green branches were placed on top of the stones and the wallaby was flung on these. After 5-10 minutes it was taken off the fire, placed on a layer of green leaves, and the singed fur was removed with a tomahawk. Although the women sometimes did this preliminary treatment, a man always did the subsequent cutting up, which was done with a metal spear blade.
The first cut was made horizontally on the ventral surface at the level of the anus, and the next on the dorsal surface along both sides to sever the leg muscles. Another cut was then made from the anus to the neck. The viscera were pulled out; and the kidneys, liver heart and lungs, and the omental and mesenteric fat were separated from the rest, and cooked on the hot stones and coals for 5 minutes. The cooked lungs were used to soak up the blood inside the carcass and then eaten. The offal was regarded as a delicacy by everybody and a certain amount of squabbling always followed its distribution.
The tail was cut off, and during the cooking was put on or alongside the body. The carcass was laid flat, dorsal side downwards, on the hot stones and ashes, and the body cavity was filled with hot stones. Sheets of paperbark formed a cover over the animal, and sand was scooped out to make an oven. Wallabies weighing 15-20 pounds were cooked for 25-35 minutes. Everything edible was eaten except the stomach and intestines. The skull was cracked open to get the brain, and the bones were broken to extract the marrow.
A number of details of this description are relevant for westernized people living in the 21st century. First, the entire carcass of an animal kill was consumed including marrow, brains, liver, kidney, heart, blood, lungs, mesenteric and omental fat and almost all visceral organs. This outline for consumption in hunter gatherer animal kills appears to be typical for humanity from the very beginning of our genus’s (Homo) appearance 2.5 million years ago.6, 7, 11, 12, 21, 28 yet varies considerably from the US and westernized pattern of only eating muscle meats (steaks, roasts, chops, ribs etc.) of domesticated animals produced in feed lots.21
Our current western practice of avoiding consumption of organ meats (brains, marrow, liver, kidney, heart and viscera) and only eating the fatty meats of grain lot produced animals causes multiple nutritional problems by altering the fatty acid profile of our ancestral diet, by reducing its micronutrient (vitamins and minerals) content and by shifting the macronutrient balance among protein, fat and even carbohydrate. These modern dietary customs lead to fundamental changes in our ancestral nutritional patterns that lead to the chronic diseases that run rampant in the western world.11-16, 18, 19, 30
So anyway, let’s get back to the topic at hand for this post – “One of the Few Quantitative Studies of Hunter Gatherer Food Choices.” I have re-analyzed the food data from this well known anthropological study of Australian Aborigines,33 using the best modern estimates for food nutrient content of these wild plant and animal foods. Below are the results of this analysis in which a couple of points become clear:
- Animal foods represent the dominant caloric source
- Cereal grains and legumes were not regularly consumed as staples
- Dairy foods were absent
Protein and fat were traditionally eaten together, but rarely or never with high glycemic load carbs, refined vegetable oils, and refined sugars. These three basic ingredients along with salt, additives and dairy products represent the basic formula for junk food in the western diet. When Australian Aborigine people became westernized and adopted “modern” diets, obesity, type 2 diabetes, high blood cholesterol levels, heart disease and other diseases of civilization became the norm for a once lean and healthy group of people.
Loren Cordain, Ph.D., Professor Emeritus
Dr. Loren Cordain is Professor Emeritus of the Department of Health and Exercise Science at Colorado State University in Fort Collins, Colorado. His research emphasis over the past 20 years has focused upon the evolutionary and anthropological basis for diet, health and well being in modern humans. Dr. Cordain’s scientific publications have examined the nutritional characteristics of worldwide hunter-gatherer diets as well as the nutrient composition of wild plant and animal foods consumed by foraging humans. He is the world’s leading expert on Paleolithic diets and has lectured extensively on the Paleolithic nutrition worldwide. Dr. Cordain is the author of five popular bestselling books including The Paleo Diet, The Paleo Answer, and The Paleo Diet Cookbook, summarizing his research findings.
1. Eaton SB, Konner M. Paleolithic nutrition. A consideration of its nature and current implications. N Engl J Med. 1985 Jan 31;312(5):283-9.
2. Eaton, S.B., Cordain, L. (1997). Old genes, new fuels: Nutritional changes since agriculture. World Review of Nutrition and Dietetics, 81: 26-37.
3. Eaton SB, Eaton SB Jr, Cordain L, Mann N, Sinclair A. (1998). Dietary intake of long chain polyunsaturated fatty acids during the paleolithic. World Review of Nutrition and Dietetics, 83: 12-23.
4. Cordain L. (1999). Cereal grains: humanity’s double edged sword. World Review of Nutrition and Dietetics, 84: 19-73.
5. Cordain L, Miller J, Mann N. (1999). Scant evidence of periodic starvation among hunter-gatherers (letter). Diabetologia, 42: 383-84.
6. Cordain L, Brand Miller J, Eaton SB, Mann N, Holt SHA, Speth JD. Plant to animal subsistence ratios and macronutrient energy estimations in world wide hunter-gatherer diets. American Journal of Clinical Nutrition, 2000, 71:682-92.
7. Cordain L, Watkins BA, Mann NJ. Fatty acid composition and energy density of foods available to African hominids: evolutionary implications for human brain development. World Review of Nutrition and Dietetics, 2001, 90:144-161.
8. Eaton SB, Cordain L, Eaton SB. An evolutionary foundation for health promotion. World Rev Nutr Diet 2001; 90: 5-12.
9. Eaton SB, Strassman BI, Nesse RM, Neel JV, Ewald PW, Williams GC, Weder AB, Eaton SB 3rd, Lindeberg S, Konner MJ, Mysterud I, Cordain L. Evolutionary health promotion. Prev Med 2002;34:109-118.
10. Eaton SB, Cordain L. Evolutionary Health Promotion. A consideration of common counter-arguments. Prev Med 2002;34:119-123.
11. Cordain L, Eaton SB, Brand Miller J, Mann N, Hill K. The paradoxical nature of hunter-gatherer diets: Meat based, yet non-atherogenic. Eur J Clin Nutr 2002;56 (suppl 1):S42-S52.
12. Cordain L, Watkins BA, Florant GL, Kehler M, Rogers L, Li Y. Fatty acid analysis of wild ruminant tissues: Evolutionary implications for reducing diet-related chronic disease. Eur J Clin Nutr, 2002;56:181-191.
13. Cordain L, Eaton SB, Brand Miller J, Lindeberg S, Jensen C. An evolutionary analysis of the etiology and pathogenesis of juvenile-onset myopia. Acta Opthalmolgica, 2002,80:125-135.
14. Cordain L. The nutritional characteristics of a contemporary diet based upon Paleolithic food groups. J Am Neutraceut Assoc 2002; 5:15-24.
15. Cordain L, Lindeberg S, Hurtado M, Hill K, Eaton SB, Brand-Miller J. (2002). Acne vulgaris: A disease of civilization. Archives of Dermatology,138: 1584-90.
16. Cordain L, Eades MR, Eades MD. (2003). Hyperinsulinemic diseases of civilization: more than just syndrome X. Comp Biochem Physiol Part A:136:95-112.
17. Lindeberg S, Ahren B, Cordain L, Nilsson-Ehle P, Vessby B, Nilsson A. Determinants of serum triglycerides and high-density lipoprotein cholesterol in traditional Trobriand Islanders – the Kitava Study. Scand J Clin Lab Invest 2003;63:175-180.
18. Lindeberg S, Cordain L, Eaton B. Biological and clinical potential of a Palaeolithic diet. J Nutr Environ Med 2003;13:149-160.
19. O’Keefe J.H., Cordain L. Cardiovascular disease as a result of a diet and lifestyle at odds with our Paleolithic genome: how to become a 21st century hunter-gatherer. Mayo Clin Proc 2004;79:101-108.
20. Lindeberg S, Ahren B, Cordain L, Rastam L. Serum uric acid in traditional Pacific Islanders and in Sweden. J Intern Med 2004; 255:373-378.
21. Cordain L, Eaton SB, Sebastian A, Mann N, Lindeberg S, Watkins BA, O’Keefe JH, Brand-Miller J. Origins and evolution of the western diet: Health implications for the 21st century. Am J Clin Nutr 2005;81:341-54.
22. Abuissa H, O’Keefe JH, Cordain, L. Realigning our 21st century diet and lifestyle with our hunter-gatherer genetic identity. Directions Psych 2005;25: SR1-SR10.
23. Cordain L., Hickey MS. Ultraviolet radiation represents an evolutionary selective pressure for the south-to-north gradient of the MTHFR 677TT genotype. Am J Clin Nutr 2006;84:1243.
24. Eaton SB, Cordain L, Sparling PB, Cantwell JD. Evolution, body composition and insulin resistance. Preventive Medicine, 2009;49:283-285.
25. Ramsden CE, Faurot KR, Carrera-Bastos, P, Sperling LS, de Lorgeril M, Cordain L. Dietary fat quality and coronary heart disease prevention: a unified theory based on evolutionary, historical, global and modern perspectives. Curr Treat Options Cardiovasc Med; 2009;11:289-301.
26. Eaton SB, Konner MJ, Cordain L. Diet-dependent acid load, Paleolithic nutrition, and evolutionary health promotion. Am J Clin Nutr 2010;91:295-97.
27. O’Keefe JH, Vogel R, Lavie CJ, Cordain L. Achieving hunter gatherer fitness in the 21st century. Am J Med 2010 Sep 13. [Epub ahead of print]
28. Remko S. Kuipers1, Martine F. Luxwolda1, D.A. Janneke Dijck-Brouwer1, S. Boyd Eaton, Michael A. Crawford, Cordain L, and Frits A.J. Muskiet. Estimated macronutrient and fatty acid intakes from an East African Paleolithic diet. Brit J Nutr , 2010 Dec;104(11):1666-87.
29. O’Keefe JH, Vogel R, Lavie CJ, Cordain L. Organic Fitness: Physical Activity Patterns Compatible with our Hunter Gatherer Genetic Legacy. Physician and Sports Medicine 2010, 38 (4):11-18.
30. Carrera-Bastos P, Fontes Villalba M, O’Keefe JH, Lindeberg S, Cordain L. The western diet and lifestyle and diseases of civilization. Res Rep Clin Cardiol 2011; 2: 215-235.
31. O’Keefe JH, Vogel R, Lavie CJ, Cordain L. Exercise Like a Hunter Gatherer: A Prescription for Organic Physical Fitness. Prog Cardiovasc Dis. 2011;53:471-9.
32. Fontes-Villalba M, Carrera-Bastos P, Cordain L.African hominin stable isotopic data do not necessarily indicate grass consumption. Proc Natl Acad Sci U S A. 2013 Oct 22;110(43):E4055. doi: 10.1073/pnas.1311461110. Epub 2013 Sep 23.
33. Anthropology and Nutrition, vol 2 of Records of the American Australian Scientific Expedition to Arnhem Land, ed. Charles P. Mountford, Melbourne University Press, Melbourne, Parkville, N.2, Victoria, Australia, 1960.