Vegetarians are healthier than omnivores - Scientific evidence

Some people insist that it’s nutritionally necessary to eat meat, milk and eggs and, therefore, it’s right that animals are raised and killed to be eaten. But this argument ignores common sense and disrespects medical science. If it were true that we have to eat meat and other animal products, then there would be no people who abstain from doing so because they would all be dead. But there are such people, alive and well, and medical science supplements common observations with evidence to show that they are often healthier than omnivores. 

Consider the position statement of the leading authority on nutrition in North America based on their seventeen-page review of the recent nutrition research:

"It is the position of the American Dietetic Association and Dietitians of Canada that appropriately planned vegetarian diets are healthful, nutritionally adequate, and provide health benefits in the prevention and treatment of certain diseases. . . Well-planned vegan and other types of vegetarian diets are appropriate for all stages of the life cycle, including during pregnancy, lactation, infancy, childhood, and adolescence. . .  A vegetarian, including vegan, diet can meet current recommendations for all of these nutrients. . . Vegetarian diets offer a number of nutritional benefits, including lower levels of saturated fat, cholesterol, and animal protein as well as higher levels of carbohydrates, fiber, magnesium, potassium, folate, and antioxidants such as vitamins C and E and phytochemicals. Vegetarians have been reported to have lower body mass indices than nonvegetarians, as well as lower rates of death from ischemic heart disease; vegetarians also show lower blood cholesterol levels; lower blood pressure; and lower rates of hypertension, type 2 diabetes, and prostate and colon cancer."

So this defense of eating animals is either ignorant of, or disrespectful towards, the huge (and growing) body of research that shows the health benefits from eating a diet based on vegetables, legumes, fruits and whole grains, and ignores the growing literature detailing the variety of harms for humans that can result from the production and consumption of animal products. 

The argument standing for eating meat as a need to keep our body healthy and alive has therefore a false empirical premise: it is not supported by science nor by medical research. It is the continuing tradition of the mainstream culture but it does not mean that it does not need evolution to a higher perspective.

Source: Nobis, N. (2008). Reasonable humans and animals: An argument for vegetarianism. Between the Species.