By Jade Brinkoetter, MS, RD, NASM-CPT
When looking for the ‘cutting edge’ to enhance performance, diet is an area that many elite athletes look to manipulate. On any day of the week, you may find a professional athlete using social media to advertise a new diet they are trying, and thousands of followers faithfully backing them. Likely fueled by the recent documentary The Game Changers, the trend of adopting a plant-based diet (PBD) has taken the athletic world by storm. Although there is no formal definition for a PBD, the term is often used interchangeably with a vegan diet, meaning it omits all animal-derived products (Barnard et al., 2019). The well-researched vegan diet is touted for its ability to improve overall health; noteworthy claims include a decreased risk for cardiovascular disease, hypertension, and dyslipidemia, as well as increased insulin sensitivity and improved blood glucose control (Barnard et al., 2019). With an increasing number of athletes at all levels looking to adopt a PBD, it is important to be aware of both the benefits and risks that accompany this lifestyle change.
PBD and Performance
What seems to be most attractive about a PBD to athletes are the athletic performance improvements to endurance and recovery that it claims to provide. In comparison to the Western pattern diet, which is generally high in saturated fat and refined carbohydrates from sources like high-fat meats, dairy, packaged foods, and sugar-sweetened beverages, a PBD emphasizes complex carbohydrates (Wirnitzer, 2020). A result of a diet high in complex carbohydrate sources like starchy vegetables, whole grains, and legumes, is maximized glycogen storage in the muscle, providing prolonged energy and endurance. In addition, the antioxidants and polyphenols present in a diet full of fruits and vegetables can lead to improved endothelial function and reduced inflammation, promoting quicker recovery and improved oxygen delivery to body tissues. The decreased consumption of saturated fat, which has been shown to slow down recovery and promote inflammation, supports improved blood flow (Barnard et al., 2019). As such benefits could mean an increase in performance and an advantage over the competition, it is understandable why this diet appeals to so many athletes. But, many may not realize that these benefits are still possible without complete elimination of animal products.
Nutrients of Concern
Many are quick to publicize their success upon implementing a PBD, and fail to mention, or even recognize, the risks associated with improper execution. By excluding multiple foods, like dairy, animal meats, and eggs, from the diet, an individual puts themselves at an increased risk of developing deficiencies from nutrients that are obtained either primarily or solely from these sources (Rogerson, 2017). An individual’s intake of protein, omega-3 fatty acids, calcium, vitamin D, vitamin B12, iron, carnitine and zinc must be closely monitored to ensure adequacy when a PBD is followed. Deficiencies in these important macro- and micronutrients can lead to a variety of problems such as anemia, impaired immune function, and injury. It is imperative that those following a PBD supplement vitamin B12, since there are no plant-based sources (Jakše et al., 2020). Although there are plant-based whole food sources of iron, calcium, omega-3 fatty acids and zinc, they are less readily absorbed and should therefore be closely monitored through blood work or food logs. Additional inclusion of fortified food sources and supplementation may be necessary to fill the gaps (Rogerson, 2017).
While each of the aforementioned nutrients are important, PBD debates often center around protein. Many will point out that protein needs can be met using solely plant-based sources, which is true; however, it is much more challenging to accomplish. Absorption of plant-based proteins is decreased compared to animal sources due to their molecular structure and the large amount of fiber decreasing digestibility (Vliet, Burd, & Loon, 2015). Additionally, unlike animal sources that contain all of all the essential amino acids, plant-based proteins are often incomplete, lacking one or more of these essential building blocks that must be provided by dietary intake. With these considerations in mind, it is important for those following a PBD to consume a variety of plant-based protein sources, as well as increase their total protein consumption at least 10% above the recommended intake to ensure an adequate amount of each essential amino acid and to compensate for decreased digestibility (Rogerson, 2017). It is likely that supplementation with a plant-based protein powder will be necessary to meet the increased need, along with education on the safety and quality standards that should be considered when choosing a product.
A PBD can cause complications for athletes looking to alter their body composition. A typical PBD that is high in fiber and low in calories can promote early satiety, which may be helpful for weight loss. However this can pose challenges for athletes looking to gain weight, requiring unique diet alterations. These athletes will likely need to increase their eating frequency and require further education of how to incorporate energy dense foods. If adequate calories are not obtained over a prolonged period of time, symptoms of relative energy deficit, such as muscle loss, reduced strength, and fewer training adaptations, can occur. In addition, muscle acquisition is more challenging with a PBD due to lower consumption of leucine, an important essential amino acid that triggers muscle protein synthesis. Although leucine can be found in plant sources like soy and lentils, it is highest in, and most readily available from, dairy and meat. A diet lacking animal products also lacks creatine, meaning those following a PBD have lower creatine stores and may benefit from supplementation to support supramaximal exercise performance (Rogerson, 2017).
Who is a PBD right for?
A well-executed PBD can adequately support athletic performance. However, it requires consistency and a strong sense of commitment. What may be beneficial and achievable by some does not mean it is right for all; it is important to evaluate if a PBD is right for each individual. According to a survey done by the Humane Research Council, 84% of vegetarians and vegans return to eating meat (Melnick, 2014). Some important factors to keep in mind when considering a PBD include: the individual’s knowledge level and ability to create a well-rounded meal plan (or access to assistance from a Registered Dietitian), an individual’s food preferences to support achieving adequate variety in plant-based protein intake, and the financial ability to purchase quality food and supplements in an optimal quantity to achieve their needs.
Inclusive not Exclusive
There is a reason plant-based diets are trending among elite athletes. The overall health and performance benefits supported by an increased intake of whole, plant-based foods is undeniable. However, the benefits athletes are seeing are most likely attributable to the inclusion of more plants, replacing nutrient-poor foods that typically comprise a Western diet, as opposed to the exclusion of all animal products. Contrary to popular narrative, including animal products alongside plant-based foods does not negate the benefits of eating more plants. It may not be social media-worthy but a well balanced diet based on plants that includes moderate amounts of dairy, eggs, fish, and lean protein can adequately support sport performance, as well. Plant-based does not have to mean plant exclusive.
This article was written by a Collegiate and Professional Sports Dietitian Association Registered Dietitian (RD). To learn more about sports nutrition and CPSDA, go to www.sportsrd.org
Barnard, N., Goldman, D., Loomis, J., Kahleova, H., Levin, S., Neabore, S., & Batts, T. (2019). Plant-Based Diets for Cardiovascular Safety and Performance in Endurance Sports. Nutrients, 11(1), 130. doi:10.3390/nu11010130
Barr, S. I., & Rideout, C. A. (2004). Nutritional considerations for vegetarian athletes. Nutrition, 20(7-8), 696-703. doi:10.1016/j.nut.2004.04.015
Jakše, B., Jakše, B., Pinter, S., Pajek, J., Godnov, U., & Mis, N. F. (2020). Nutrient and Food Intake of Participants in a Whole-Food Plant-Based Lifestyle Program. Journal of the American College of Nutrition, 1-16. doi:10.1080/07315724.2020.1778584
Melnick, M. (2014, December 04). Turns Out, Your Vegetarianism Probably Is Just A Phase. Retrieved November 30, 2020, from https://www.huffpost.com/entry/vegetarian-phase_n_6270584?ir=Science
Rogerson, D. (2017). Vegan diets: Practical advice for athletes and exercisers. Journal of the International Society of Sports Nutrition, 14(1). doi:10.1186/s12970-017-0192-9
Twombley, B. (2020, May 20). I am not defined by my protein. [Conference session]. The Collegiate and Professional Sports Dietitians Association 2020 Conference.
Vliet, S. V., Burd, N. A., & Loon, L. J. (2015). The Skeletal Muscle Anabolic Response to Plant- versus Animal-Based Protein Consumption. The Journal of Nutrition, 145(9), 1981-1991. doi:10.3945/jn.114.204305
Wirnitzer, K. C. (2020). Vegan Diet in Sports and Exercise – Health Benefits and Advantages to Athletes and Physically Active People: A Narrative Review. International Journal of Sports and Exercise Medicine, 6(3). doi:10.23937/2469-5718/1510165
You Might Also Like
A Nutritional Approach To Periodization
Periodization is a term we live and die by in the field of performance. What ...