This is an excerpt from Nancy Clark's Sports Nutrition Guidebook-6th Edition.
Many active people do not eat animal protein. Some just eat no red meat; others eat no red meat, chicken, fish, eggs, or dairy foods. They may find animal protein hard to digest or believe it is bad for their health, unethical to eat, or erosive to the environment. (Cattle are a source of greenhouse gas that contributes to global warming.) Meatless Mondays (and other days, too) are a good idea for the planet! And a balanced vegetarian diet is indeed a good investment in good health. A plant-based diet tends to have more fiber, less saturated fat, and more phytochemicals—active compounds that bolster the immune system, reduce inflammation, and are health protective.
The trick to eating a balanced vegetarian diet is to make the effort to replace meat with plant proteins. That is, if you eliminate the meatballs from your pasta dinner, add an alternative source of plant-based protein. Do not simply fuel up only on pasta and neglect your protein needs. You can get adequate protein to support your sports program by including kidney beans, chickpeas, hummus, nut butter, tofu, nuts, veggie burgers, edamame, and other forms of plant protein in each meal.
Tofu (soybean curd) and other soy products, such as soy burgers and soy milk, are smart additions to a meat-free diet. They contain a source of high-quality protein that is similar in value to animal protein. Note that a Boca Burger (soy protein) has far less protein than a hamburger, however (refer to table 7.2). Despite popular belief among male athletes, the plant estrogens in soy do not have a feminizing effect, do not reduce testosterone levels, and do not impair fertility (Messina 2010). All athletes can enjoy soy foods in moderation, as with any food, as a health-promoting part of a balanced sports diet.
For lacto-vegetarians (who consume dairy foods), milk and (Greek) yogurt are simple ways to add extra high-quality protein to meals and snacks. Although they have been given a bad rap because they are high in saturated fat, recent studies question whether a connection exits between dairy fat and heart disease and stroke regardless of the milk fat levels (de Oliveira Otto et al. 2018). This controversial topic is worthy of continued research, so until the American Heart Association gives the green light for full-fat dairy foods, a wise plan is to choose mostly reduced-fat dairy foods and balance full-fat choices into an overall healthy eating pattern. That said, blue cheese and other “moldy cheeses” may be a positive addition to the diet regardless of their saturated fat: They support gut bacteria that promote good health (Petyaev and Bashmakov 2012).
Milk, other dairy foods, eggs, and all animal sources of protein contain all the essential amino acids and are often referred to as complete proteins. The protein in soy foods such as tofu, tempeh, edamame, and soy milk are also complete proteins. The protein in rice, beans, pasta, lentils, nuts, fruits, vegetables, and other plant foods are incomplete because they contain low levels of some of the essential amino acids. Therefore, vegetarians must eat a variety of foods to get a variety of amino acids that combine with incomplete proteins to make them complete. Vegetarians who drink milk can easily do this by adding soy milk or dairy products to each meal, for example, combining (soy) milk with oatmeal or sprinkling grated low-fat (soy) cheese on beans. Note that rice and almond milks are not nutritionally equal to soy milk, but rather are very poor protein sources (see chapter 1).
Vegans (strict vegetarians who eat no dairy, eggs, or animal protein) need to consistently eat a variety of foods to optimize their intake of a variety of amino acids over the course of the day. The following combinations work particularly well together; they complement each other by boosting the limiting amino acid:
- Grains plus beans or legumes, such as rice and beans, bread and split-pea soup, tofu and brown rice, corn bread and chili with kidney beans
- Legumes plus seeds, such as chickpeas and tahini (as in hummus), tofu and sesame seeds
- Added soy products (or dairy, if nonvegan), such as cereal and (soy) milk, baked potato and Greek or soy yogurt, hummus wrap with low-fat (soy) cheese
By following these guidelines, vegetarian athletes can consume an adequate amount of complete protein every day. They may, however, lack iron and zinc, minerals found primarily in meats and other animal products. Vegans also need to be sure they get adequate riboflavin, calcium, and vitamin B12, either through a supplement or from carefully selected food sources.