What is a vegetarian diet?
Some people follow a "vegetarian" diet, but there's no single vegetarian eating pattern. The vegan or total vegetarian diet includes only foods from plants: fruits, vegetables, legumes (dried beans and peas), grains, seeds and nuts. The lactovegetarian diet includes plant foods plus cheese and other dairy products. The ovo-lactovegetarian (or lacto-ovovegetarian) diet also includes eggs. Semi-vegetarians don't eat red meat but include chicken and fish with plant foods, dairy products and eggs.
Are vegetarian diets healthful?
Most vegetarian diets are low in or devoid of animal products. They’re also usually lower than nonvegetarian diets in total fat, saturated fat and cholesterol. Many studies have shown that vegetarians seem to have a lower risk of obesity, coronary heart disease (which causes heart attack), high blood pressure, diabetes mellitus and some forms of cancer.
Vegetarian diets can be healthful and nutritionally sound if they’re carefully planned to include essential nutrients. However, a vegetarian diet can be unhealthy if it contains too many calories and/or saturated fat and not enough important nutrients.
What are the nutrients to consider in a vegetarian diet?
- Protein: You don't need to eat foods from animals to have enough protein in your diet. Plant proteins alone can provide enough of the essential and non-essential amino acids, as long as sources of dietary protein are varied and caloric intake is high enough to meet energy needs.
- Whole grains, legumes, vegetables, seeds and nuts all contain both essential and non-essential amino acids. You don't need to consciously combine these foods ("complementary proteins") within a given meal.
- Soy protein has been shown to be equal to proteins of animal origin. It can be your sole protein source if you choose.
- Iron: Vegetarians may have a greater risk of iron deficiency than nonvegetarians. The richest sources of iron are red meat, liver and egg yolk -- all high in cholesterol. However, dried beans, spinach, enriched products, brewer's yeast and dried fruits are all good plant sources of iron.
- Vitamin B-12: This comes naturally only from animal sources. Vegans need a reliable source of vitamin B-12. It can be found in some fortified (not enriched) breakfast cereals, fortified soy beverages, some brands of nutritional (brewer's) yeast and other foods (check the labels), as well as vitamin supplements.
- Vitamin D: Vegans should have a reliable source of vitamin D. Vegans who don’t get much sunlight may need a supplement.
- Calcium: Studies show that vegetarians absorb and retain more calcium from foods than nonvegetarians do. Vegetable greens such as spinach, kale and broccoli, and some legumes and soybean products, are good sources of calcium from plants.
- Zinc: Zinc is needed for growth and development. Good plant sources include grains, nuts and legumes. Shellfish are an excellent source of zinc. Take care to select supplements containing no more than 15-18 mg zinc. Supplements containing 50 mg or more may lower HDL ("good") cholesterol in some people.
What meal plans are recommended?
Any type of vegetarian diet should include a wide variety of foods and enough calories to meet your energy needs.
- Keep your intake of sweets and fatty foods to a minimum. These foods are low in nutrients and high in calories.
- Choose whole or unrefined grain products when possible, or use fortified or enriched cereal products.
- Use a variety of fruits and vegetables, including foods that are good sources of vitamins A and C.
- If you use milk or dairy products, choose fat-free/nonfat and low-fat varieties.
Related AHA publications:
- Easy Food Tips for Heart-Healthy Eating (also in Spanish)
- Controlling Your Risk Factors... heart attack and stroke
Related AHA Scientific Statements: