Notes

A vegetarian diet delivers complete nutrition and can provide health benefits. According to the American Dietetic Association, a vegetarian diet can meet protein requirements, provide all the essential amino-acids (the building blocks of protein), and improve health. It can also provide all the necessary vitamins, fats, and minerals, and can improve one’s health. [1] [2] According to the USDA and the Food and Agriculture Organization of the United Nations, meat is not an essential part of a healthy diet.
Meat is the most convenient protein source available. In one serving, meat provides all the essential amino acids (the building blocks of protein), as well as essential nutrients such as iron, zinc, and B vitamins. [61] Most plant foods do not provide adequate levels of all the essential amino acids in a single serving.
A vegetarian diet can help alleviate world hunger. Over 10 pounds of plant protein are used to produce one pound of beef protein. [24] If these grains were fed to humans instead of animals, more food would be available for the 925 million people in chronic hunger worldwide. [105] Research from Cornell University found that the grain used to feed US livestock alone could feed 800 million people. [107]
Eating meat provides healthy saturated fats, which enhance the function of the immune and nervous systems. Saturated fats contain the fat-soluble vitamins A, D, E and K, [49] and the cholesterol from saturated animal fat is needed for the proper function of serotonin receptors in the brain. According to a Feb. 7, 2014 study by researchers at the Institute of Social Medicine and Epidemiology, vegetarians "suffer significantly more often from anxiety disorder and/or depression." [133] Low cholesterol levels have been linked to depression. Saturated fats are also essential for building and maintaining cell health, and help the body absorb calcium. [101]
A vegetarian diet reduces the chances of developing kidney stones and gallstones. Diets high in animal protein cause the body to excrete calcium, oxalate, and uric acid—the main components of kidney stones and gallstones. A diet high in animal protein is responsible for the high rates (15% of men and 7% of women) of kidney stones in the United States, according to a peer-reviewed Nov. 15, 1999 study. [6]
Meat is the best source of vitamin B12, a vitamin necessary to nervous and digestive system health. Although it is also found in eggs and dairy, [46] a peer-reviewed July 2003 study showed two in three vegetarians were vitamin B12 deficient compared to one in 20 meat eaters. [47]
A vegetarian diet provides a more healthful form of iron than a meat-based diet. Studies have linked heme iron found in red meat with an increased risk of colon and rectal cancer. [4] Vegetarian sources of iron like leafy greens and beans contain non-heme
Vegetarians live longer. A Mar. 12, 2012 peer-reviewed study of 121,342 people found that eating red meat was associated with an increased risk of death from cancer and cardiovascular disease. [121] A peer-reviewed 2003 study found that adherence to vegetarian diets or diets very low in meat for 20 years or more can increase life expectancy by 3.6 years. [86] A peer-reviewed July 9, 2001 study of Seventh-Day Adventists who were vegetarian (or ate very little meat) showed longevity increases of 7.28 years for men and 4.42 years for women. [76] On June 3, 2013 a peer-reviewed study of 73,308 people found that a vegetarian diet is associated with a 12% reduction in all-cause mortality. [130]