Peter D. Ward in The Call of Distant Mammoths suggests that the Clovis Culture may have suffered from Protein Poisoning. He says the Bushmen of the Kalahari suffer from this ailment because of the leaness of the meat they consume and the lack of vegetation in the Kalahari. When they succumb to it the remedy is to eat only the fat surrounding the organs such as the heart and kidney. (p.149 The Call of Distant Mammoths)