Many people does not make the difference between high fat and high protein diets. High fat diet consists mainly of organ meat, fatty meat, egg yolk, butter, seafood, fatty fish etc. High protein diet consists mainly of lean muscle meat.
For example, the Inuits and Native Americans of the Great Plains knew how to stay healthy, especially early spring when the animals they hunted were lean. Sometimes native populations had no choice but to subsist on rabbit meat (leanest of the animals) for a short period of time, until other animals (caribou) fattens up and become ready for hunting. "Living on lean game is somewhere between unhealthy and fatal." (-
Stephan Guyenet). This is called
Rabbit Starvation.