Vegetarian Diet?

the evidence that vegetarian and vegan diets almost always cause a multitude of nutritional deficiencies is overwhelmingly conclusive.

During the course of a lifetime, vegetarian diets will not reduce your risk of developing chronic diseases and will not allow you to live longer. Rather, this abnormal way of eating will predispose you to a host of health problems and illnesses. Vegetarianism is an unnatural way of eating that has no evolutionary precedent in our species.

— Loren Cordain Ph.D. - The Paleo Answer