How much animal protein do we need? Is animal-based protein better than plant-based protein? Looking for evidence in the vegetarian, Mediterranean and other diets

The large amount of animal protein that is currently consumed in western diets is a relatively recent phenomenon. The majority of the world eat a largely plant-based diet and it is only in relatively recent times that meat has become a major part of western diets. Prior to the shift to agriculture which started some 10,000 years ago, it has been argued that Palaeolithic man gained the majority of his nutrition from red meat consumption. However, there are great problems with this from a scientific point of view. Because of the limited data, some of which has been extrapolated back from modern times, definite statements made by those who produce red meat. A particular claim about the need for such foods for good brain development remains unproven scientifically. See the section on the Palaeolithic diet.