Vegetarian diets have become very popular; the number of Americans who describe themselves as vegetarians has more than doubled in the past ten years. It is now estimated that one in ten Americans consider themselves vegetarians. However, many are not too strict. Recently 20% of vegetarians reported that they ate meat at least once a month and fish and poultry more often, leading some to describe this type of diet as "near vegetarian." Vegetarians may include dairy products such as milk and cheese in their diets, as we recommend, sometimes with eggs. This is the diet closest to the ideal as described in the classical texts of Yoga and by my teachers. Vegetarians who avoid all animal products, including eggs and dairy, are usually called vegans; some eat only fruit or raw foods. This, nutritionally speaking, is a vast territory, with significant variations from one so-called vegetarian to another.

The greatest number of vegetarians in America today usually report that they have adopted the diet to improve health, lose weight, and prevent or postpone some common chronic ills of aging. It is likely, therefore, that many vegetarians are more flexible about occasional meat eating, since the diet is based more on a perceived self-interest – good personal health rather than on principle. Also, this motivation creates some difficult relationship dynamics for couples and families: a lot of nagging often accompanies meals and snacks when someone has been "told" to "cut down" on fatty meats for heart health, but still yearns for a double cheeseburger.

Let’s look at some definitions.

• Lacto-ovo-vegetarian – This is the largest subgroup of vegetarians, who eat eggs and dairy foods in addition to the cereal grains, fruits, vegetables, legumes, nuts, and seeds that comprise the plant-based food foundation. This can easily be a very healthy diet provided that eggs and butterfat are limited in quantity to keep saturated fat and cholesterol in check.
  
• Lactovegetarian – These vegetarians eat dairy products but not eggs.
  
• Vegan – Strict vegetarians who abstain from all animal products sometimes go so far as to avoid honey, as well as wool and leather products. Less than 5% of vegetarians report that they are vegans. Today, this style is easier to pursue as many soy-based vegan foods are now available in supermarkets. Special care is needed to ensure vitamin, mineral, and calorie adequacy, and experts recommend vitamin and mineral supplements or fortified and special foods such as blackstrap molasses, nutritional yeast, and vegetable fats be added to the diet.
  
• Fruitarian – a highly restrictive diet consisting solely of fruits, nuts, and seeds. Even allowing for some foods commonly considered as vegetable, but botanically classified as fruit, it is difficult, if not impossible, to provide adequate nutrients. Another related highly restrictive diet, sometimes called the "living food diet," includes uncooked, fermented, or sprouted plant foods and their juices. The restrictions that are implied by both of these vegetarian diet styles make adequate nutrition unlikely.

Vegetarians have a greatly reduced death rate from all causes, probably as a result of many factors. These include eating more fruits, vegetables, and polyunsaturated fatty acids, and less saturated fat, cholesterol, and alcohol than the rest of the population. Also, vegetarians tend to have a healthier lifestyle, because they smoke less, weigh less, and are more physically active. Current research trends are devoted to identifying the specific phytochemicals in fruits and vegetables that are responsible for vegetarians’ overall better health. Here are some of the conclusions from past research efforts:

• The longer the duration of a vegetarian diet, the greater reduction in all cancer death rates.
  
• More than one serving of fruit daily reduces both lung and stomach cancer risk.
  
• Dried fruit, tomatoes, and legumes (peas, beans, and lentils) provide protection from prostate cancer.
  
• The risk of pancreatic cancer is strikingly reduced by regular consumption of legumes and dried fruits.
• Legumes help reduce the risk of colon cancer, as does more fiber.
  
• Vegetarians have a lower risk of heart disease, due to lower weight, reduced blood fats and lower blood pressure.
  
• Whole wheat bread and nuts, especially walnuts, help reduce the risk for heart disease.
  
• The high complex carbohydrate and fiber vegetarian diet gives some protection from diabetes.
  
• Bone density appears to be higher in vegetarians, reducing the risk of osteoporosis.