> At our request he began eating lean meat only, although he had previously noted, in the North, that very lean meat produced digestive disturbances. On the 3rd day nausea and diarrhea developed. When fat was added to the diet, a full recovery was made in 2 days.
Concerning the meat,
> The meat used included beef, lamb, veal, pork, and chicken. The parts used were muscle, liver, kidney, brain, bone marrow, bacon, and fat. While on lecture trips V. S. occasionally ate a few eggs and a little butter when meat, was not readily available. The carbohydrate content of the diet was very small, consisting solely of the glycogen of the meat. The men, except during short periods of special observation, ate as much as they wanted and proportioned the lean meat to the fat as they desired. T. S., in 31 days of special diet in the ward in which he was free from digestive disturbances, took an average of 0.81 kilos of meat per day while K. A. for 110 days averaged 0.70 kilos per day.
There is protein toxemia where the kidneys can't deal with the wastes; it's as far as I know always a symptom of kidney damage. https://en.m.wikipedia.org/wiki/Protein_toxicity
Also, worth noting that a meat-heavy diet can also kill you from lack of fat. This is known as protein poisoning. This obviously depends on what your source of meat is.
(1) https://www2.dmu.dk/1_viden/2_publikationer/3_fagrapporter/r...
I don't think not eating muscle tissue makes any sense in modern day. Nobody will just eat whale organ tissue any more, realistically. I mean, if you really do eat it, it might work, but will you really do that? You need those lean proteins from animals and you'll hopefully supplement fats, vitamins and minerals from other sources. Animals muscle is very Omega 6 rich, so ideally you wanna eat lean proteins (chicken, turkey breast, lean red meat...) and supplement your diet with Omega 3 sources like salmon, acai berry, walnut, flaxseed etc...