High school students elect to follow vegetarian and vegan diets for many reasons, such as compassion toward animals, desire to protect the environment and desire to optimize health and/or performance. According to a national poll in 2014, about five percent of high school students in grades 9-12 are vegetarian (never eat meat, fish, seafood or poultry), which includes about one percent who are vegan (never eat eggs, dairy or flesh foods). By comparison, a similar poll revealed that 3.3 percent of American adults are vegetarian or vegan.
Although coaches and parents of new vegetarians may be concerned about the adequacy of vegetarian and vegan diets for athletes, health experts in the United States, Canada and across the globe agree that a well-balanced vegetarian diet – which contains whole grains, vegetables, fruits, legumes, nuts and seeds – supports the training demands of athletes and provides health benefits as well.
Vegetarian diets help in the prevention of chronic diseases such as heart disease and certain cancers and may also enhance recovery following exercise. Following are some key strategies for ensuring adequate nutrition in the vegetarian and vegan high school athlete:
Meeting but not exceeding energy (or calorie) needs is the first priority of all athletes. Daily energy needs vary among girls and boys, and further depend on the athlete’s body size, body composition, training regimen, growth and general activity pattern.
Some athletes who follow vegetarian diets have difficulty meeting energy needs due to the high volume of food needed (due to low calorie density) or hectic schedules that prevent adequate time to eat. Additionally, some athletes are not prepared for making healthy vegetarian choices at school, home or team events, which can result in undereating or the selection of less nutritious foods (i.e., soda and chips are technically vegetarian). Striving for five to eight meals/snacks per day and executing adequate planning (“brown bag” lunches, snacks packed in the gym bag or kept in the school locker) may help the athlete meet energy needs. Athletes who intentionally restrict calories and food choices may be using vegetarianism to mask an eating disorder.
A common misconception is that athletes who adopt vegetarian diets will struggle with getting enough protein. Meeting even the higher protein needs of sports training (along with adolescent growth), nevertheless, is typically not an issue if the athlete consumes adequate calories and selects a variety of protein foods (see Table), including beans, nuts, tofu and peanut butter. As was once believed, it is not necessary to eat specific combinations of plant foods in the same meal but to eat a variety of protein-containing foods over the course of the day. A protein-containing snack or meal within the hour after an intense practice may also aid in muscle repair and recovery.
Carbohydrate and Fat
Carbohydrates are an important fuel source and should make up the bulk of the athlete’s diet5. While muscles rely on both carbohydrate and fat to fuel physical effort, carbohydrate is the only fuel that can sustain the moderate-to-high level activity required by most sports. Although the body stores carbohydrate as “glycogen” in muscle and liver, these stores become depleted during prolonged and intense intermittent exercise common in most high school sports. Depleted glycogen stores result in tiredness and fatigue. Consuming enough carbohydrate ensures glycogen stores are restocked after hard practices and can result in better performance on game (or race) day.
Vegetarian athletes tend to fair well on carbohydrate intake, but the challenge for many high school athletes – vegetarian or not – is to obtain carbohydrates from whole food sources, such as whole grain bread, pasta, quinoa and starchy vegetables, rather than from overly processed carbohydrates and simple sugars. Fat on the other hand is still important to the athlete’s diet. Judicious selection of healthy fats (Table) and cheeses adds calories, enhances the taste of plant foods and ensures adequate absorption of many nutrients.
Vitamins and Minerals
A well-balanced vegetarian diet provides an abundance of nutrients including Vitamins A, C, E and K; folate; potassium; and magnesium. Depending on food choices, however, meeting daily requirements for iron, zinc, calcium and Vitamin B12 can present a challenge as these nutrients either are found less abundantly in the vegetarian diet or are less well absorbed.
Iron and zinc are important for optimal performance and growth. In addition, iron status can become compromised during seasonal training, with female high school athletes particularly vulnerable. Although vegetarian athletes can achieve adequate iron and zinc status by selecting foods rich in these nutrients (Table), knowledge about the factors than enhance and impair absorption is helpful. Iron and zinc are best absorbed when rich sources are paired with Vitamin C-containing foods (Table), whereas iron absorption is impaired by excess consumption of tea, coffee, milk or soda at the same meal.
Calcium is important for bone health and is a concern for vegan athletes and vegetarians who consume little to no dairy products. Opting for non-dairy, calcium-containing foods is an easy remedy and is preferred over calcium supplements. Many vegetarian sources including kale, tofu and Chinese cabbage are better absorbed than milk. Vitamin B-12 is imperative for cellular growth and nerve function. This vitamin is a concern for vegan and near-vegan athletes because it is found only in animal products. Thus, Vitamin B-12–fortified foods or a Vitamin-B12 supplement should be consumed regularly. Additionally, athletes with little to no intake of both calcium and Vitamin B12 can feel “healthy,” but long-term marginal deficiency can result in poor bone health and irreversible nerve damage.
Vegetarian and vegan diets that contain a variety of whole grains, vegetables, fruits, legumes, nuts and seeds can provide the protein, carbohydrate, fat vitamins and minerals required by the high school athlete. Depending on dietary choice, emphasis of foods high in protein, iron, zinc, calcium and Vitamin B-12 will ensure adequate nutrient status. Athletes failing to meet calorie or nutrient needs on vegetarian diets should see their physician or registered dietitian nutritionist.
D. Enette Larson-Meyer is an associate professor, Human Nutrition and Food Program Option, at the University of Wyoming.