Ironman triathlete Brendan Brazier, track and field Olympian Carl Lewis, and bodybuilder Kenneth Williams are examples of vegan athletes. But can an athlete really follow a vegan diet without compromising one’s performance? Does vegan diet include enough protein? This article highlights the key pros and cons of vegan diet when combined with sports, and the best strategies for an athlete to meet the enhanced caloric and protein needs with a plant-based diet.

Why vegan diet?

First, let’s make definitions clear: In vegan diet, all food is non-animal origin (no meat, poultry, eggs, dairy, honey, gelatin). Vegetarian diet on the other hand excludes animal flesh but may include eggs and dairy. (Venderley & Campbell 2006)

Vegetarian (including vegan) diets are associated with health benefits including lower risk for cardiovascular disease, type 2 diabetes, and cancer, and lower levels of LDL cholesterol and body mass index compared to omnivorous diets (Fuhrman & Ferreri 2010). But as omnivorous diet, vegan diet also may be harmful for athlete if not constructed adequately (Mandali 2011). When planned carefully, vegetarian (and vegan) diet can provide adequate energy intake and appropriate amount of each macronutrient (Venderley & Campbell 2006).

Calorie intake & protein requirements

Plant foods are generally low in calorie density due to their lower fat and higher fiber content. This makes it especially important for vegan athletes to ensure adequate energy intake. Having frequent meals and snacks and consuming meat alternatives (e.g. tempeh and tofu), dried fruits, avocados, and nuts are great strategies for ensuring proper energy intake. (Venderley & Campbell 2006)

Insufficient protein intake may result in poor recovery from exercise (Fuhrman & Ferreri 2010). Without careful planning and proper supplementation, vegan diet may lack equivalent protein amounts whereas it is rather easy to gain proper amounts of protein in omnivorous diet (Jäger et al. 2017). This is due the fact that protein density in plant-based foods is lower compared to animal-based foods, so vegan athlete must consume various protein sources whereas omnivorous athlete may consume only meat to meet daily protein requirements. But in practice, vegan athletes’ diets usually meet or even exceed recommendations for athlete protein intake. (Venderley & Campbell 2006) Table 1 shows protein content of various plant sources.

Although plant-based protein is not as high in essential amino acids as protein from animal origin, vegan diet can provide all essential and nonessential amino acids if various plant foods are consumed over the course of day (Ilander et al. 2014; Venderley & Campbell 2006). Although one plant-based protein source alone does not provide all amino acids, they are not required to be consumed within one meal (Venderley & Campbell 2006).

Micronutrients in vegan diet

Intense training regimen suppresses immune function and increases the level of viral infections. As vegan diet is high in micronutrients (e.g. fiber, antioxidants, vitamins, minerals), it may offer significant benefits as illnesses do not disrupt the training plan. (Fuhrman & Ferreri 2010) Athletes benefit on plant-based diets also based on the antioxidant-rich status (e.g. vitamins C and E, beta-carotene), as antioxidants reduce oxidative stress caused by exercise (Venderley & Campbell 2006).

Compared to omnivorous diet, athlete following vegan diet must be more aware about potential deficiencies in micronutrients (Fuhrman &a Ferreri 2010). Micronutrients to keep in mind are calcium, iron, zinc, iodine, vitamins B12 and D, omega-3, and creatine (Fuhrman & Ferreri 2010; Venderley & Campbell 2006). The best way to ensure adequate micronutrient intake is to consume nutrient-rich whole plant foods (Fuhrman & Ferreri 2010). Table 2 shows the recommended daily intakes, food-based sources and whether supplementation is recommended for vegan athletes.

Exercise causes iron losses, and iron deficiency is common for all athletes despite their diet (vegan or omnivorous). Interestingly, it is common for omnivorous diets to contain less iron than vegan diets. (Fuhrman & Ferreri 2010) Generally vegan athletes are not recommended to take calcium or iron as supplements, as it is rather easy to receive an adequate amount of iron and calcium from whole foods. In addition, iron supplementation may cause the body to gain too high iron stores which again increases the risk for cancer and cardiovascular disease. (Fuhrman & Ferreri 2010)

Creatine most likely enhances exercise performance and body composition especially for short-term high-intensity exercises. Creatine stores in muscle are lower for vegetarians (and vegans) compared to non-vegetarians, as sources for creatine are mainly animal origin. (Jäger et al. 2017; Venderley & Campbell 2006) Therefore, creatine supplementation is recommended for vegan athletes.

Researchers’ opinion

For athletes, vegetarian (and vegan) and omnivorous diets are do not compromise performance outcomes: Vegetarian diet may even promote better aerobic capacity for athletes compared to omnivorous diet. This may be due to plant-based diet’s high level of carbohydrate and antioxidants. (Lynch et al. 2016; Venderley & Campbell 2006)

Researchers agree that vegan diet is appropriate for serious athletes (Fuhrman & Ferreri 2010). With careful planning, vegan diet can meet athletes’ energy and macro- and micronutrient requirements (Venderley & Campbell 2006). Considered the fact that vegan diet promotes better health and longer lifespan than animal-based diet, it is worth to stress the pros of vegan diet in an athlete’s health (Fuhrman & Ferreri 2010).

Sources

Fuhrman J. & Ferreri D. 2010. Fueling the Vegetarian (Vegan) Athlete. 1537-890X/0904/233Y241 Current Sports Medicine Reports. American College of Sports Medicine.

Ilander et al. 2014. Ruoka – Laatua lautaselle. Ilander O., Mursu J., Laakkonen M. Liikuntaravitsemus – tehoa, tuloksia ja terveyttä ruuasta. VK Kustannus Oy.

Jäger R., Kerksick C., Campbell B., Cribb J. et al. 2017. International Society of Sports Nutrition Position Stand: protein and exercise. Review. Journal of the International Society of Sports Nutrition 2017 14:20. https://doi.org/10.1186/s12970-017-0177-8

Lynch M., Wharton C. and Johnston C. 2016. Cardiorespiratory Fitness and Peak Torque Differences between Vegetarian and Omnivore Endurance Athletes: A Cross-Sectional Study. Nutrients 2016: 8, 726,

Mandali S. 2011. Coaching the Vegetarian Athlete. Journal of Physical Education, Recreation & Dance. Feb 2011: 82 (2), ProQuest.

Venderley A. & Campbell W. 2006. Vegetarian diets. Nutritional Considerations for Athletes. Sports Med 2006: 36 (4): 293-305.