A vegetarian diet involves the practice of only eating foods that do not come from animal sources. Instead, vegetarians typically consume plant-based sources of foods such as fruits, grains, legumes, nuts and vegetables. Some vegetarians eat eggs and dairy products while others do not.

People choose vegetarianism for many different reasons, including ethical concerns about eating animal products, religious beliefs or preference for the flavor of plant-based foods. These diets may provide many health benefits because plant-based foods are rich in nutrients, fiber and phytonutrients and low in various substances that may cause harm (e.g., cholesterol and saturated fat).

Most vegetarians can get all the nutrients they require simply by following a well-balanced diet that includes low-fat dairy products, whole grains, vegetables and fruits. However, strict vegetarians – or vegans – who do not consume any animal products face nutritional challenges that can only be addressed by careful dietary planning.

Nutrients that may not be present in adequate amounts in some vegetarian diets include calcium, iron, protein, vitamin B12, vitamin D and zinc.

Special populations must be especially careful about maintaining adequate nutrient content within a vegetarian diet. Women who are pregnant or breastfeeding generally are urged to wait until a later time to switch to a vegetarian diet. Women who are already vegetarians may not have to alter their diet much to ensure that their baby develops normally. However, it may be a good idea to consult with a registered dietitian.