Protein poisoning (also referred to colloquially as rabbit starvation, mal de caribou, or fat starvation) is an acute form of malnutrition caused by a diet deficient in fat and carbohydrates, where almost all calories consumed come from the protein in lean meat. The concept is discussed in the context of paleoanthropological investigations into the diet of ancient humans, especially during the last glacial maximum and at high latitudes. The term rabbit starvation originates from the fact that rabbit meat is very lean, with almost all of its caloric content from protein rather than fat, and therefore a food which, if consumed exclusively, would cause protein poisoning. Animals in harsh, cold environments similarly become lean. The reported symptoms include initial nausea and fatigue, followed by diarrhea and ultimately death. Observations In Appian's Roman History, Volume I, Book VI: The Wars in Spain, Chapter IX, page 223, the author notes a multitude of Roman soldiers dying of severe diarrhea after eating mostly rabbits while besieging the city Intercatia in approx 150 B.C. Appian wrote: The explorer Vilhjalmur Stefansson is said to have lived for years exclusively on game meat and fish, with no ill effects. The same is true for his fellow explorer Karsten Anderson. As part of his promotion of meat-only diet modeled on Inuit cuisine, and to demonstrate the effects, in New York City beginning in February 1928, Stefansson and Anderson "lived and ate in the metabolism ward of Russell Sage Institute of Pathology of Bellevue Hospital, New York" for a year, with their metabolic performance closely observed, all this partly funded by the Institute of American Meat Packers. Researchers hoping to replicate Stefansson's experience with rabbit starvation in the field urged him to cut the fat intake in his all-meat diet to zero. He did, and experienced a much quicker onset of diarrhea than in the field. With fat added back in, Stefansson recovered, although with a 10-day period of constipation afterwards. The study reported finding no previous medical literature examining either the effects of meat-only diets, which appear to be sustainable, or on rabbit starvation, which is fatal. Stefansson wrote: A World War II-era Arctic survival booklet issued by the Flight Control Command of the United States Army Air Forces included this emphatic warning: "Because of the importance of fats, under no conditions limit yourself to a meat diet of rabbit just because they happen to be plentiful