Vegetarians and vegans sometimes don't get enough nutrition. People are generally deficient in energy, protein, vitamin B12 and minerals such as iron and zinc. Athletes, especially those who do not eat any animal products, must organize their diets carefully, because a lack of nutrients can prevent them from achieving excellent results.

As evidenced by the plethora of sports supplements and special diets, nutrition keeps many athletes busy. In a literature study, a British researcher investigated whether top athletes could get enough nutrition from a vegetarian (meat- and fish-free) or vegan (vegetable-only food) diet.

Herbivores

Vegetarians, athletes who eat an exclusively plant-based diet, often seem to consume too few important nutrients. In particular, they are often deficient in energy, protein, vitamins, and minerals. While a vegan diet can theoretically meet almost all of these needs, in practice it seems difficult to follow a sufficiently balanced diet.

Energy for endurance athletes

Endurance athletes in particular need enough carbohydrates for optimal performance. Most carbohydrate drinks and gels are suitable for vegetarians and vegans, and a plant-based diet can theoretically contain enough carbohydrates. However, vegan athletes often eat too little. This can be explained by the fact that plant sources of protein, such as nuts and beans, contain a lot of fiber. These can quickly lead to a feeling of fullness, which means athletes don't eat enough. Endurance athletes can choose some low-fiber varieties of carbohydrate sources such as white rice, pasta or white bread to get enough energy.

Building Muscle

Vegetarians can get enough protein to recover and build muscle by eating eggs and dairy products. For vegans, it's more difficult:Plants do contain protein, but their composition is different from the protein needed to build muscle cells and other tissues in the body. A protein-rich plant product often does not contain all the amino acids necessary for muscle building. Therefore, the recommendation for vegans is to combine proteins from different sources, such as grains and nuts, in one meal. Because these products contain different amino acids, athletes can consume all the nutrients at the same time. In practice, this means that for the same level of muscle building, more plant protein than animal protein is usually needed. For this reason, it's best for strict vegan athletes to exceed the minimum recommended amount of protein for athletes.

In addition to useful protein, (red) meat also contains creatine. This substance promotes muscle growth, and many athletes can benefit from creatine supplements. This seems to be truer for vegetarians or vegan athletes than for athletes who eat meat regularly.

Vitamins and minerals

Finally, Rogerson's study found that the diets of vegans typically contain too little vitamin B12 and vitamin D, and not enough iron, zinc, calcium and iodine. These are all necessary for good health and optimal athletic performance. In cases of deficiency, taking supplements as recommended by a certified sports nutritionist may be advisable. Even with supplements, vegan athletes must carefully modify their diets. Regular consumption of animal products (e.g., dairy and meat) appears to be more likely to result in optimal athletic performance.