Americans are becoming more diet conscious and decreasing their consumption of red meat, fat and cholesterol. Approximately 2.5 percent of adults in the United States and 4 percent of adults in Canada now follow vegetarian diets. A vegetarian diet can offer significant health benefits but can also result in nutritional deficiencies if not properly planned. With healthy balance and nutritional variety, most vegetarians can meet their daily needs.
Types of Vegetarian Diets
A strict vegan will avoid all sources of meat, poultry, fish, eggs and dairy. The diets consists of fruits, vegetables, whole grains, nuts and seeds. An ovo-vegetarian will incorporate eggs along with plant foods, and a lacto-vegetarian will add in dairy products. A lacto-ovo vegetarian will consume both eggs and dairy products. The type of vegetarianism and the degree of restriction in food groups determines the risk of specific nutrient deficiencies.
Strict vegans may be at risk for deficiencies of protein, iron, zinc, omega-3 fatty acids, calcium, phosphorus, vitamin D, B-12 and other B-vitamins. Fortified cereals, legumes, peas, nuts, seeds and soy provide protein, iron, zinc and B vitamins, while fortified soy milk is an excellent source of calcium. Green leafy vegetables are rich in calcium and most B-vitamins. Iron is also present in green leafy vegetables, legumes and dried fruits but in smaller quantities and in a less readily absorbed form than in animal products. Omega-3 fatty acids in fish can be substituted with nuts, seeds and flaxseed. A daily multivitamin is beneficial for vegans to ensure optimal intake.
The nutritional intake of the lacto-ovo vegetarian is enhanced by incorporating eggs and dairy products in the diet. Milk, yogurt and cheese supply protein, calcium, phosphorus, zinc, vitamin D and B-complex vitamins. Eggs are an excellent source of protein and offer additional iron, vitamin B-12 and other B vitamins.
Despite the potential for nutritional deficiencies, scientific evidence supports the advantages of consuming a vegetarian diet. The Academy of Nutrition and Dietetics -- formerly the American Dietetic Association -- and Dietitians of Canada assert that planned vegetarian diets are healthful and nutritionally adequate, and provide health benefits in the prevention and treatment of certain diseases. Vegetarians consume a variety of fruits, vegetables, whole grains, nuts and seeds that are rich in antioxidants, fiber, potassium, omega-3 fatty acids and vitamins A, E, C and K. The nutrients present in plant products have been linked to a decreased incidence of high blood pressure, certain types of cancers, obesity, diabetes and heart and gastrointestinal disease. The diet is also low in fat, cholesterol and saturated fat, which further reduces the risk of cardiovascular disease.
- The Vegan Society: Sources of Nutrients for Vegans
- Nutrition Concepts and Controversies; Frances Sizer
- Forum of Nutrition: Vegetarian Diets: What Are the Advantages?
- Canadian Journal of Dietetic Practice and Research: Position of the American Dietetic Association and Dietitians of Canada: Vegetarian Diets
Diane Tomkin is a registered and licensed dietitian with more than 30 years of professional experience in clinical nutrition. As a nutrition consultant, she runs a private practice in Long Island. Tomkin holds a master's degree in health-care administration and health education. She has taught graduate and undergraduate classes at Long Island University.