in contrast to non-human primates that subsist mostly on plant foods even though most of them consume meat sporadically. Domestication of beef cattle occurred more than 8500 years ago and it is logical to assume that meat consumption increased compared to when animals were hunted. Although the U.S. Department of Agriculture (USDA) maintains per capita food production data back to only 1909, there are many books that point to higher beef consumption in the U.S. during the nineteenth century, which has led to estimates of intake of two to three times what is currently consumed when chronic, non- communicable diseases were rare (Smil, 2002). The consumption of cooked meat results in greater intake of high quality protein that is denatured by heat and therefore provides more digestible protein, more energy availability, and an increase in brain size that is thought to be