According to the latest edition of the USDA's Dietary Guidelines for Americans, "Consumption of [plant] foods is associated with a substantially lower risk for many chronic diseases, including certain types of cancer" and "Vegetarian diets are consistent with the Dietary Guidelines for Americans and can meet Recommended Dietary Allowances for nutrients."[21]

The concept of "protein complementing" -- a need to eat certain types of foods in combination at each meal to utilize the protein -- gained widespread notoriety in the 1970s due to Frances Lappés Diet for a Small World, but it has long since been dismissed as unnecessary in all but the most deficient diets.[15]

Vegetarians and Vegans have less than one-half the risk of heart disease as the general population. For every 1% decrease in blood cholesterol levels, heart disease risk decreases by 2-4%. Vegans have as much as 35% lower cholesterol levels. Cholesterol levels increase due to consumption of saturated fat and cholesterol. In contrast to meat, most plants are very low in saturated fat (and fat overall) and plants contain NO cholesterol.[4]

A low-fat vegetarian diet combined with exercise and stress management has been shown to reverse heart disease.[15]

Vegetarians have one-half the incidence rate of adult-onset diabetes. Consumption of cows' milk during infancy increases risk of childhood-onset diabetes. Regular consumption of cows' milk throughout childhood doubles diabetes risk. Most diabetics put on a low-fat vegetarian diet and a regular exercise program have a reduction in diabetes-related problems and many are able to stop taking insulin/medication.[15]

Osteoporosis is a disease of protein excess, not calcium deficiency. Calcium is leeched from the bones when the body metabolizes protein. Meat is very high in protein, so despite lower calcium consumption, vegetarian and vegan women have bone mass similar to or better than that of meat-eaters.[15]

Five hundred people die each year in the US from bacteria in meat. Another 6.5 million fall ill.[6] More than 70% of the poultry in stores are contaminated with Salmonella or Campylobacter, or both![11]

Consumption of meat is estimated to cost $30-60 billion in direct medical costs due to the greater incidence of heart disease, cancer, obesity, and other health problems. This is comparable to the estimated $50 billion medical costs attributed to smoking.[4]

Most adults are lactose intolerant, although it varies by ethnicity: Native Americans and Southeast Asians have incidence rates of more than 90% and Northern Europeans have rates below 10%. Consumption of dairy products can lead to cramping, diarrhea, and nausea.[15]

In the United States, the onset of puberty occurs at the age of 12-13 years of age, but in China, where diets are very low in fat and contain very few animal products, puberty occurs much later at 17 years.[3,12] This was also true more than a hundred years ago when the typical western diet was also less meat-based.[3] Today, vegetarian girls reach menarche later than omnivore girls. Besides the societal problems worsened by early sexual maturity (e.g., teen pregnancy and STDs), early menarche is linked to a greater risk for breast cancer later in life.[15]

Farm animals are fed 30 times more antibiotics than are used by humans. (Primarily done to increase growth rates, the antibiotics are also used to prevent disease in the overcrowded, filthy environment of modern farms.) This has driven the evolution of drug-resistant bacteria strains. Many antibiotics are thus no longer effective against pneumonia and only one is left which prevents staph infections.[6] Microbiologist Alexander Tomasz of Rockefeller University calls this "nothing short of a medical disaster."[5]

In 1996, there were 2193 health advisories in effect cautioning people not to eat fish from certain waterways due to pollution. The advisories covered 15% of lakes, 5% of rivers, and 100% of the Great Lakes.[23]