Vegetarianism has been practiced for centuries in many cultures and religions. Although it is not difficult to plan and implement a nutritionally balanced vegetarian or vegan diet, there are several nutrients that require special attention for the athlete. However, before discussing the special nutrient considerations, it is important to define the variety of vegetarian styles.
There are four primary styles:
(1) Vegan – eats only plant foods;
(2) Fruitarians – eat fruits, nuts, honey, and vegetable oils;
(3) Lacto-vegetarians – eat dairy products and plant foods; and
(4) Lacto-ovo-vegetarian – eat dairy products, eggs and plant foods, (Haddad, 1994).
In general, the wider the variety of foods consumed, the easier it is to meet one’s nutritional needs and RDIs (Reference Daily Intakes).
The Fruitarian plan is not widely recommended because it can lead to nutrient deficiencies among all age groups. When carefully planned, a vegetarian diet encourages a high carbohydrate intake, a rich source of anti-oxidants (cancer fighting nutrients), specifically Vitamins A, C, E, carotenoids, magnesium, dietary fibre, and a reduced intake of saturated fat (animal fat) and cholesterol, (Dwyer, 1994).
The lacto-ovo-vegetarian who chooses not to eat red meat, and instead replaces meat protein with cheese and egg protein, can consume far more saturated fat from the cheese and cholesterol from the egg. For the vegetarian, soy protein is a healthier alternative to high-fat cheese and regular eggs. When carefully designed, research has shown that a vegetarian meal plan can help with the prevention and treatment of several chronic diseases specifically, heart disease, diabetes and cancer.
The calorie density of the foods consumed by a vegetarian (e.g. fruits, vegetables, whole grains), tends to be less than an individual who includes meat in their meal plan. The high fiber content of a plant-based diet can also create a feeling of fullness more quickly and cause fewer total calories to be consumed.
Recommendation: Include calorie dense foods (e.g., nuts) with meals to meet your energy (calorie) requirements.
Plant proteins tend to be limiting in one or more amino acids; proteins are considered to be complete if they supply all the essential amino acids when consumed at the recommended protein level, (Young, 1975).
Recommendation: (1) Consume complimentary proteins which are two food proteins that make up for each other's lack of an essential amino acid, and thereby together create a complete protein (e.g. tofu and rice, rice and red beans, rice and lentils, soybeans and peanuts, soybeans and rice, soybeans and sesame seeds, soybeans and black-eyed peas or green peas, green beans and almonds, and corn tortillas and pinto beans. (2) The protein quality from soy is equivalent to that in animal sources (Young, 1991).
The best sources of iron are from animal products. Iron is a functionally required for hemoglobin to bind with oxygen and transport it from the lungs to working muscles. During exercise adequate iron has been proposed to reduce fatigue and enhance endurance.
Recommendation: (1) Consume whole grains, prune juice, dried apricots, dried prunes and raisins, nuts and legumes. (2) Consuming a rich source of vitamin C, (e.g., orange juice, or ascorbic acid) with every meal that contains an iron-rich plant food will enhance iron absorption, (Jacob, 1994).
Calcium is a very important mineral for the body and is required for, bones, teeth, and every muscle contraction of the body, including the heart. A vegan diet, devoid of dairy products can lead to a calcium deficiency such as osteoporosis and poor athletic performance.
Recommendation: (1) Drink fortified soybean milk or fortified orange juice (e.g. Tropicana with calcium), consume calcium-rich tofu, or calcium-fortified. (2) Consume plant sources rich in calcium such as almonds, dry beans, and green leafy vegetables.
Zinc is required for the functioning of more than 100 enzymes in the body. When you exercise, zinc helps remove carbon dioxide from the working muscles; zinc is also required for tissue repair. Zinc is required for fat, protein, and carbohydrate metabolism. Vegetables are generally poor sources of zinc. A diet high in whole grains can limit the absorption of zinc due to the phytic acid found in whole grains.
Recommendation: Consume whole grains, wheat germ, beans, nuts and seeds.
Vitamin B12 is required for normal neurological development and functioning. The earliest sign of a vitamin B12 deficiency is mental dysfunction. In exercise, vitamin B12 is required for red blood cell development and enhances endurance performance (Brouns, 1993). Vitamin B12 is found naturally only in animal products and therefore the vegan who excludes milk, dairy products and eggs from their diet, will become deficient in vitamin B12 without some vitamin B12 supplementation.
Recommendation: Consume fortified breakfast cereals, fortified yeast products, fortified soy milk and fortified soy products.
Riboflavin is required for energy metabolism and enhances aerobic performance. A major source of riboflavin is milk, which is omitted from the vegan diet.
Recommendation: Consume green leafy vegetables, whole grains, yeast and legumes.
Lacto-ovo-vegetarians are unlikely to be deficient in vitamin D if they consume fortified milk, milk products, and eggs. However, vegans can become deficient in vitamin D if their diet is not carefully supplemented and if they avoid sun exposure. In relation to exercise, vitamin D is required for bone mineral metabolism.
Recommendation: (1) Consume vitamin D fortified breakfast cereals and fortified margarine. (2) As little as 15 minutes of sun exposure per day is sufficient; however, the use of sun-blocking agents on the skin can block the beneficial effects (Holuck, 1996).
Brouns F: Nutritional Needs of athletes, Chichester, 1993, John Wiley & Sons.
Dwyer JT: Vegetarian eating patterns, American Journal of Clinical Nutrition 59:1255S, 1994.
Gibson RS: Content and bioavailability of trace elements is vegetarian diets, American Journal of Clinical Nutrition 59:1223S, 1994.
Haddad EH: Development of a vegetarian food guide, American Journal of Clinical Nutrition 59: 1248S, 1994.
Holuck MF: Vitamin D and bone health, Journal of Nutrition;126(Suppl):1595-1164S, 1996.
Jacob RA: Vitamin C. In Shils ME, Olson JA and Shike M. ed. Modern Nutrition in Health and Disease. 8th ed. Philadelphia: Lea & Febiger. 1994.
Position of the American Dietetic Association: Vegetarian diets. Journal of the American Dietetic Association; 93:1317-1319, 1993.
Young, VR: Soy protein in relation to human protein and amino acid nutrition. Journal of the American Dietetic Association; 91: 828-835, 1991.
Young, VR, Fajardo L, Murray E, Rand WM, Scrimshaw NS: Protein requirements of man: Comparative nitrogen balance response within the submaintenance-to-maintenance range of intakes of wheat and beef proteins. Journal of Nutrition: 105:534-542, 1975.
Source: American Council for Exercise
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