A vegetarian diet is a meal plan that contains mostly plants, such as vegetables, fruits, whole grains, legumes, seeds, and nuts, with little or no animal products.
Types of vegetarian diets include:
- Vegan: Diet consists of only plant-based foods.
- Lacto-vegetarian: Diet consists of plant foods plus some or all dairy products.
- Lacto-ovovegetarian: Diet consists of plant foods, dairy products, and eggs.
- Semi- or partial vegetarian: Diet consists of plant foods and may include chicken or fish, dairy products, and eggs. It does not include red meat.
Lacto-ovovegetarian; Semi-vegetarian; Partial vegetarian; Vegan; Lacto-vegetarian
A person may choose to follow a vegetarian diet for a variety of reasons, including:
- Moral or political beliefs
- The desire to eat more healthy foods
Vegetarian diets most often lead to healthier outcomes:
- Lower levels of obesity
- Reduced risk for heart disease
- Lower blood pressure
Compared to non-vegetarians, vegetarians usually eat:
- Fewer calories from fat (especially saturated fat)
- Fewer overall calories
- More fiber, potassium, and vitamin C
A well-planned, carefully monitored vegetarian diet can deliver good nutrition. Dietary recommendations vary with the type of vegetarian diet.
For children and adolescents these diets need to be carefully planned, because it may be hard to get all the nutrients needed for growth and development. Vegetarian diets are high in fiber. High-fiber diets may lack some of the calories children need for growth, and cause some growth problems.
Pregnant and breastfeeding women, as well as the elderly, should carefully monitor their vegetarian diet to reduce the risk of nutrient deficiencies.
Vitamins that may be lacking in a vegetarian diet include:
- Vitamin B12
- People who follow a vegan diet should take supplements to get this vitamin.
- Vitamin D
- Vegetarians who do not eat dairy products fortified with vitamin D may need supplements.
- Also, many people may need supplements because they do not get enough exposure to sunlight.
- Fruits and vegetables are not good sources of zinc. Zinc in plant proteins is not as available for the body to use as zinc from animal proteins.
- High-protein foods contain high amounts of zinc. Beef, pork, and lamb contain more zinc than fish. The zinc content is lower in nuts, whole grains, legumes, and yeast.
- Low-protein and vegetarian diets tend to be low in zinc. The best way to get the right amount of zinc is to eat a balanced diet that contains a variety of foods.
- Iron from fruits, vegetables, grains, and supplements is harder for the body to absorb than iron from meat.
- Females who follow a vegetarian diet need to get enough iron.
- Eating foods that are high in vitamin C at the same meal as iron-rich foods increase iron absorption. Vitamin C helps the body absorb iron.
- Phylates found in whole grains, tannins in coffee and tea, and excess calcium can reduce iron absorption.
- When proteins are digested, amino acids are left. The human body needs many amino acids to break down food.
- Amino acids are found in animal sources such as meats, milk, fish, and eggs, as well as in plant sources such as beans, legumes, soy, and nut butters.
- You do not have to eat animal products to get all the protein you need in your diet. See: Protein in diet
Vegetarian diets that include some animal products (lacto-vegetarian and lacto-ovovegetarian) are nutritionally sound. Vegan diets need to be carefully planned to include the right amounts of important nutrients.
The following are recommendations for feeding children on vegetarian diets:
- Make breast milk or formula the basis of the diet until age 1. (See: Diet for age)
- Use milk or a fortified soy formula.
- Do not limit fat in a child younger than age 2.
- Children who do not drink milk or a fortified substitute may lack the following nutrients: calcium, protein, vitamin D, riboflavin, and may need a vitamin and mineral supplement.
- Children who do not eat animal products must take vitamin B12 supplements.
- It is hard to get enough iron intake if the child does not eat meat.
NOTE: A registered dietician should review any specialized diet to make sure it meets you or your child's nutritional needs. This should be done before starting the diet.
National Academy of Sciences. Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients). National Academy Press. Washington, D.C., 2005.
National Academy of Sciences. Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. National Academy Press. Washington, D.C., 2005.
Escott-Stump S. Nutrition and Diagnosis-Related Care. 6th ed. Philadelphia, Pa. Lippincott Williams & Wilkins; 2008.
United States Department of Agriculture. Center for Nutrition Policy and Promotion. Dietary Guidelines for Americans. 2010. National Academy Press, Washington, D.C. 2010.
Sarubin Fragaakis A, Thomson C. The Health Professionals Guide to Popular Dietary Supplements. 3rd ed. Chicago, Il. American Dietetic Association, 2007.
Office of Dietary Supplements. National Institutes of Health. Accessed on February 14, 2011.
Reviewed By: Alison Evert, MS, RD, CDE, Nutritionist, University of Washington Medical Center Diabetes Care Center, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.