Twice in one June 2015 week I (Ted Slanker) was confronted and ridiculed for saying man can live exclusively on grass-fed meat. One rebuttal came from a grain-fed beef production scientist who said she preferred science to my hyperbole yet she didn't offer a scientific rebuttal. The other came from a 30-year veteran nutritionist who called my statement "promotion" and said flat out that “Man cannot live by grass-fed beef alone.” In my opinion what these people don't know about anthropology and the nutritional attributes of grass-fed animals would fill volumes of scientific literature.
Not only do we know the foundation food for all animal life is the green leaf (not seeds and nuts), but before the invention of grain farming and other farming pursuits, man ate mostly grass-fed meat because that was the easiest food to eat. Animals greatly outnumbered people. The gathering of seeds, nuts, fruit, and tubers was more labor intensive, very seasonal, and not as nutritionally satisfying as eating meat. Therefore man was a hunter and the grass-fed meats kept the green leaf at the bottom of his food chain.
At the end of this paragraph you can download the famous 1930 study of the exclusive meat diet. It may be the only scientific report of its kind. In the late 1920s scientists had become just about as afraid of the exclusive meat diet as they are today. (This was many years before the formal feedlot industry existed.) They were afraid because of developing beliefs that an exclusive meat diet was outrageous and dangerous. Yet in 1928 a few scientists were still willing to study the all meat diet and they had two very willing subjects. Today, the theory that grass-fed meat is bad for your health has reached unprecedented heights of popularity -- without any scientific evidence. The theories of Dr. John Harvey Kellogg and his cereal magnate brother W.K. Kellogg, and more recently USDA dietary guidelines, have for over a century now brought into question the very idea that grass-fed red meat should even be a part of the diet. This irrational thinking continues and funding for another study such as this 1930 research paper may be many years in the offing. There are 11 summaries in the conclusion. Read the report here.
SUMMARY AND CONCLUSIONS.
1. Two men lived on an exclusive meat diet for 1 year and a third man for 10 days. The relative amounts of lean and fat, meat ingested were left to the instinctive choice of the individuals.
2 . . . 10.
11. In these trained subjects, the clinical observations and laboratory studies gave no evidence that any ill effects had occurred from the prolonged use of the exclusive meat diet.