Aug 18, 2017Vegetarian Diets
When most people think of an optimal diet for athletic performance, they imagine covering all corners of the food pyramid–after all, that’s the best way to ensure an athlete gets the carbohydrates, protein, healthy fat, vitamins, and minerals they need to fuel their engine and promote muscle growth, right? The fact is, vegetarian athletes can and do meet all their nutritional needs despite limiting the use of animal products or eliminating them altogether. In fact, some research suggests they even have an advantage over their meat-eating counterparts.
There are many reasons why someone chooses to become a vegetarian. It may be rooted in religious beliefs, animal rights concerns, environmental consciousness, economics, health, or simply that they don’t like the taste of meat. Whatever the motivation, vegetarians who know how to adapt their diet to the demands of athletic performance enjoy much upside and practically no downside.
In 2009, The American Dietetic Association and Dietitians of Canada endorsed vegetarian diets for sports training in a joint position statement on nutrition and athletic performance. This official “seal of approval” backed up what many dietitians had been observing for years–that all else being equal, a carefully chosen plant-based training and competition diet can actually be superior to an omnivore’s regimen.
Vegetarian diets are virtually always rich in both simple and complex carbohydrates, providing efficient fuel for all training intensity levels. In addition, vegetarians tend to consume larger quantities of phytochemicals–healthy plant-based compounds such as antioxidants that help protect muscle cells and assist with building strength, extending endurance, and enhancing recovery.
With meat removed from the dietary equation, vegetarians typically don’t eat as much fat–especially saturated fat–or cholesterol. And the fat they do consume is more often “healthy fat,” such as the omega-3 fatty acids found in avocados, nuts, and seeds.
Like all people, vegetarians who eat a healthy, balanced diet can be assured of getting ample amounts of vitamins, minerals, phytonutrients, fats, carbohydrates, and protein to fuel themselves for performance, while those who eat poorly are at risk for deficiencies in things like iron, calcium, zinc, vitamins D and B12, and essential fats and amino acids. The only major difference is that vegetarians have a smaller spectrum of foods from which to choose–much smaller in the case of the most restrictive types–so they need to pay closer attention to their intake than omnivores.
When fueling for sports, one of the most basic concerns is adequate calorie consumption, which some vegetarians find challenging because plant-based foods often have lower calorie densities and more fiber. As a result, the athlete consumes less energy overall before feeling full. An easy way to overcome this is to consciously include calorie-dense foods at mealtimes–excellent choices include nuts, nut butters, seeds and oils, soy- and tofu-based meat alternatives, soy milk, textured vegetable protein, tempeh, and fruit juices and smoothies. Vegetarians should also place extra emphasis on consuming calories throughout the day in the form of snacks and beverages to increase energy intake.
Calculating protein, carbohydrate, and fat needs for vegetarians can be somewhat different than for omnivores. Carbohydrates typically aren’t a problem–in fact, a meta-analysis of 63 research studies showed that vegans and vegetarians consistently had higher dietary percentages of carbohydrates than meat eaters.
Carbohydrates for vegetarians come mainly from grains, fruits, vegetables, dairy, and dairy substitutes, and should constitute approximately six to 10 grams per kilogram of body weight (2.7 to 4.5 grams per pound) per day to replenish glycogen stores and fuel activity. For endurance athletes who train more than 60 to 90 minutes a day, the vegetarian diet is especially beneficial because of its emphasis on complex carbs. Most fruits and starchy foods provide about 15 grams of carbohydrates per serving, while milk and dairy substitutes provide around 12 grams per cup, and vegetables roughly 10 grams per cup.
As for protein, the American Dietetic Association advises that vegetarians eat roughly 10 percent more than the standard recommendation for meat eaters, because many non-meat proteins are less bioavailable than meat-based sources. This means an optimal daily intake for vegetarian athletes is roughly 1.3 to 1.8 grams per kilogram of body weight (0.5 to 0.8 grams per pound), depending on the intensity of training.
Even with meat out of the equation, there are many high-protein vegetarian food choices, including beans and peas, nuts, dairy products, fish, sport bars, and protein shakes, so getting enough just takes a little creativity and planning. Since vegans have fewer options due to the exclusion of dairy and fish, they can make up the difference with larger quantities of soy, seitan (wheat-based protein), and seeds.
Different protein sources contain different essential amino acids (EAAs)–that is, amino acids the body does not produce naturally so they must be obtained through diet. These amino acids comprise the basic building blocks of protein, and while they’re plentiful in animal products, they tend to be more limited in other foods: While a plant or dairy source may be rich in one particular EAA, it may contain very little of others. Therefore, variety is key for vegetarian athletes. They must be discouraged from getting into food “ruts” in which they eat similar meals day after day. Those who do struggle with variety should be pointed toward soy products, as these are some of the only plant-based foods that have all the essential amino acids.
In high-intensity sports, the meat-based fuel source creatine provides extra energy for working muscles. Meat eaters typically get roughly one gram of creatine per day from their diet, and the body synthesizes approximately one more gram in the liver, kidneys, and pancreas using the amino acids arginine and glycine as precursors. Research shows that vegetarians consistently have lower creatine levels than omnivores, so some study authors suggest vegetarian athletes may benefit from moderate creatine supplementation.
However, it’s important to note that the benefits and health risks of prolonged creatine use are still the subject of debate. Any athlete interested in creatine supplementation should first undergo a dietary analysis to see if they’re struggling with deficiencies that can be resolved to provide a performance and energy boost without the use of supplements.
Fats are essential for long-term energy, hormone production, and the absorption of fat-soluble vitamins including A, D, E, and K. The standard recommendation is that fat should make up 20 to 35 percent of total calories in an athlete’s diet. Research shows that vegetarians generally consume less fat than meat eaters, and this accounts for numerous health benefits, such as lower lipid levels and body mass index, and reduced risk for hypertension and diabetes. But too little fat can be problematic.
In particular, diets that do not include fish or eggs can be low in beneficial omega-3 fatty acids. Not surprisingly, vegan athletes are most at risk for deficiency. These athletes should be encouraged to get their essential fatty acids through sources such as soy, walnuts, almonds, pistachios, flax, and canola oils. There are also algae-based supplements marketed to vegetarians that are rich in specific omega-3 fatty acids such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).
When meat is eliminated from the diet, certain vitamin and mineral levels must be carefully monitored. Those who are new to vegetarianism may have been getting most of their vitamin B12, iron, calcium, and zinc from animal products without knowing it.
Studies have found that zinc levels are typically lower in vegetarians than omnivores, which is not surprising since 50 to 70 percent of zinc in our diet regularly comes from meat and dairy. Zinc is essential for protein synthesis, immune system function, and new blood cell formation.
The recommended daily amount is 11 milligrams for men and nine milligrams for women, but these values may be too low for competitive athletes, since strenuous exercise can lead to increased zinc loss through sweat and urine. To further complicate matters for vegetarians, a plant compound called phytate found in the hulls of many nuts, grains, and seeds may inhibit zinc bioavailability in humans.
According to The American Dietetic Association’s position paper on vegetarian diets, one way to increase zinc absorption from beans, grains, and seeds is to soak them in water before eating them. Another effective method is to eat fortified cereals and other zinc-rich foods together with citrus fruit, which helps promote absorption.
Calcium recommendations for active males and pre-menopausal females are typically 1,200 to 1,500 milligrams daily for adolescents and 1,000 milligrams for adults. Calcium is essential for bone integrity and also plays an important role in circulatory and nervous system health. Low calcium intake can increase the risk of stress fractures, especially in amenorrheic female athletes.
Some research suggests that vegetarians may have lower calcium needs than omnivores because the higher protein and sodium intake typical of meat eaters leads to greater calcium excretion, but the jury is still out on that theory. In any case, there’s no need to gamble, since calcium is easy to find in dairy products and fortified dairy alternatives like soy, rice, and almond milks, tofu, juices, shakes, and greens.
Iron is critical for all athletes because it synthesizes hemoglobin and myoglobin, which transport oxygen to muscles. Athletes and growing adolescents are at particularly high risk for iron deficiency, partly because of the natural demands of physical growth and partly due to iron loss through heavy sweating. Another iron-related issue is hemolysis, or the destruction of red blood cells, which can be caused by high-volume endurance training.
As with zinc, the standard daily recommendation for iron consumption (which ranges from eight to 18 milligrams per day depending on age and gender) is likely too low for vegetarians because of the lower absorption rate of non-meat iron sources. The form of iron found in plants, called non-heme iron, is less bioavailable than the heme iron found in meat and fish.
Many vegetarians take an iron supplement to ensure they get an adequate supply of this vital mineral. But it’s not hard to get enough iron in the vegetarian diet through beans, fortified cereals, greens, and dried fruits. Consuming iron-rich foods along with citrus fruit and other fruits and vegetables rich in vitamin C, such as broccoli, red and green peppers, and strawberries, also helps to increase iron absorption.
One other nutrient for which vegetarians may be at risk of deficiency is B12. Found only in animal products and foods fortified with it, B12 is an important coenzyme required for the normal metabolism of protein, carbohydrates, and fats. The daily recommendation is 2.4 micrograms, which can be obtained through fortified cereals, bars, shakes, rice and soy milk, and nutritional yeast. If a vegetarian athlete is unsure of their B12 level, a simple blood test can determine if they have a sufficient supply.
Athletes who choose the vegetarian lifestyle can give themselves an edge over their meat-eating peers. Whether they do it for health reasons, moral reasons, or simply personal preference, as long as they monitor their intake of key macro- and micronutrients, they’re well positioned to achieve optimal fueling for performance and health.