Vegetarians are people who do not eat meat products and may also not consume dairy products or eggs. They may do so for health reasons or for philosophical and moral reasons. Some people, such as Seventh Day Adventists, are vegetarians because of their religious beliefs.
Many people eat plant foods simply because they are cheaper than animal products.
Dwyer says vegetarians' longevity is equal to or greater than that of non-vegetarians, but is influenced in Western countries by healthy lifestyle habits, such as not smoking, abstaining or practicing moderation in alcohol use, exercising, getting enough rest and seeking help for health problems. As with any diet, it's important for the vegetarian diet to include many different foods, since no one food contains all the nutrients needed for good health. Of particular concern may be calcium , iron , riboflavin , vitamin D and vitamin B12 . Vitamin B12, for example, occurs only in animal foods. The Institute of Food Technologists recommends that vegetarians who don't eat dairy foods take calcium supplements, especially during pregnancy, when breast-feeding.