You might choose to follow a vegetarian diet because you believe it will improve your health. Diets rich in plant foods, such as grains, beans, fruits and vegetables, reduce the risk of many chronic diseases. Animal products, especially fatty cuts of meat and full-fat dairy products, are linked to clogged arteries, heart disease, stroke and certain cancers, according to the Center for Science in the Public Interest. Vegetarians, especially vegans, must be very careful to avoid dangerous deficiencies by planning a diet that includes all the necessary nutrients.