I have come to the conclusion that Mother Nature never wanted us to become strict and unyielding vegetarians. There is nothing natural about it at all. Visit any vegan, and you will find his cabinet of vitamin supplements at least as well stocked as his larder. The truth is that humans were designed to be omnivores, complete with all purpose dentition and digective systems. Vegetarianism is not our natural diet. Anthropologists know that for most of the past million years of evolution, humans have eaten meat, especially fish and low-fat wild game. The only source of plant protein that does not require cooking to become digestable is, I think, nuts. But cooking was invented only fifty thousand years ago, long after most of our physiology and genetoic structure had evolved. I cannot think of a traditional, nonindustrial culture (we used to call them primitive cultures) that practices vegetarianism if it can help it. Vegetarianism is always the product of scarcity, of religion, or of ideology, including nutrional fads and fashions.

From Jeffrey Steingarten, 'Vegging Out' in; "The Man Who Ate Everything" pp141-2 Vintage, New York 1998.