This is patently false. A human being experiences no physiologial need for animal protein. This is obviously not the case for true carnivores, like felines.
All humans are physiologically vegetarian. We live in a world eith hyper developed agriculture that is capable of providing many times the abundance of vegetable foods that is all a human needs.
Willful consumption of meat beyond that is purely gluttony, egotism and indoctrinated belief. It is a worldwide cult which you and I were raised in and this cult is causing the veritable holocaust of billions of animals yearly.