Elite and amateur athletes have long been manipulating their diets to gain a competitive edge over their opponents. Many athletes promote improved performance and athletic success following a gluten-free diet. Novak Djokovic swears by it, while Andy Murray feels weak and lacking energy on a gluten free diet. So, does a gluten free diet improve athletic performance?
Many athletes say a gluten free diet enhances their training, recovery and gives them a competitive edge. Despite this, there is a lack of clinical evidence supporting the use of a gluten free diet to enhance performance in sport.
Perceived performance enhancement of the gluten free diet
To date only one study has evaluated the short-term impact of gluten intake upon performance outcomes in cyclists. No overall effects were found on performance, gastrointestinal (GI) symptoms or wellbeing as a result of consuming 16g of wheat gluten daily while following a gluten free diet. After 7 days there was no significant difference between performance measures of power, heart rate, cadence or total work competed over a 15 minute TT.
Athletes avoiding gluten felt that their performance was impaired while consuming gluten and that performance improvements after excluding it was possibly related to low-level inflammation. Reduced GI distress after removing gluten may validly improve performance, highlighting the importance of testing for coeliac disease.
The belief concept
Despite the limited evidence supporting any performance enhancing effect of a gluten free diet, it’s popularity continues to increase.
Some athletes perceive improved energy, pace and other performance outcomes, even though testing shows no difference. After 4 weeks gluten free, one athlete felt more energy and pace despite any actual improvements. Three female athletes reported improvements in running times and training quality after following a gluten free diet, however this was not tested or confirmed. One survey found over 56% of athletes believed a gluten free diet improved their performance, with 74% believing it improved body composition for better sports performance.
Belief in novel and exciting performance-enhancing treatments can produce performance improvements – even when no real treatment effect exists. Belief in an intervention can contribute 1-3% improvements in performance. Also known as a placebo effect, the belief concept plays a complicated role in influencing outcomes.
Is a gluten free diet nutritionally adequate?
Depending on the starting point, removing gluten could either improve or compromise an athlete’s diet. Many athletes find going gluten free makes them more conscious about eating a healthy and balanced diet, so they eat less processed food and more fruits, vegetables and gluten free whole-grains. Perceived improvements could coincide simultaneously these sorts of positive dietary changes influencing hearth – not necessarily related to gluten itself.
A poor-quality gluten free diet can result in inadequate intakes of B-vitamins, thiamin, riboflavin, niacin, folate, iron and fibre, which could negatively impact performance. Gluten free foods not only cost more, but can be lower in protein, fibre and have a higher glycaemic index (GI).
While many athletes take supplements to avoid micronutrient deficiencies, it is important to evaluate the overall nutritional quality of the diet to ensure there is enough macronutrients (carbohydrates, fats, protein) and micronutrient (vitamins, minerals, phytonutrients etc). Eat a diverse range of gluten-free whole grains and include plenty of fruit and vegetables and legumes for balance.
Research is now showing that dietary changes and restrictions can impact gut bacteria populations and gut health. While diets containing wheat have improved good gut bacteria populations, a gluten-free or low-FODMAP diet can negatively impact gut health, within four weeks after excluding gluten from the diet.
Does a gluten free diet improve athletic performance?
There is no doubt that an athlete’s diet plays a critical role in training adaptations and athletic performance. Belief in a gluten free diet may improve perceived performance, even if there isn’t any detectable change.
Before going gluten free, get tested for coeliac disease, irritable bowel syndrome or non-coeliac gluten sensitivity to exclude any underlying medical conditions which may impact their performance or GI distress.
Gluten free athletes should focus on boosting the nutritional quality of their overall diet, include a variety of wholegrain gluten free grains, ensure adequate fibre intake and lower glycemic index.
- Gaesser, G. a., & Angadi, S. S. (2012). Gluten-free diet: Imprudent dietary advice for the general population? Journal of the Academy of Nutrition and Dietetics, 112(9), 1330–1333.
- LIS, D., STELLINGWERFF, T., KITIC, C. M., AHUJA, K. D. K., & FELL, J. (2015). No Effects of a Short-Term Gluten-free Diet on Performance in Nonceliac Athletes. Medicine & Science in Sports & Exercise, 47(12), 2563-2570
- Lis, D. M., Stellingwerff, T., Shing, C. M., Ahuja, K. D. K., & Fell, J. W. (2015). Exploring the Popularity, Experiences, and Beliefs Surrounding Gluten-Free Diets in Nonceliac Athletes. International Journal of Sport Nutrition and Exercise Metabolism, 25(1), 37–45.
- Black, K. E., Skidmore, P. M. L., & Brown, R. C. (2012). Energy intakes of ultraendurance cyclists during competition, an observational study. International Journal of Sport Nutrition and Exercise Metabolism, 22(1), 19–23.
- Therrian, F. J. (2015). Macronutrient intake and fluid status of elite female distance runners at moderate altitude. Kansas State University.
- Newman, K., & Beachy, K. (2015). Excluding Gluten in a Healthy Collegiate Runner. Journal of Sports Medicine and Allied Health Sciences: Official Journal of The Ohio Athletic Trainers Association, 1(1).
- Halson, S. L., & Martin, D. T. (2013). Lying to win-Placebos and sport science. International Journal of Sports Physiology and Performance, 8, 597–599.
- Quinteros-Fernandez, S. A. (2015). Knowledge and Behaviors Surrounding a Gluten-Free Diet Between Medically and Self-Diagnosed Individuals. Syracuse University.
- Shepherd, S. J., & Gibson, P.R. (2013). Nutritional inadequacies of the gluten-free diet in post recently-diagnosed and long-term patients with celiac disease. Journal of Human Nutrition and Dietetics: The Official Journal of the British Dietetic Association, 26(4), 349-58.
- Wu, J. H. Y., Neal, B., Trevena, H., Crino, M., Stuart-Smith, W., Faulkner-Hogg, K., … Dunford, E. (2015). Are gluten-free foods healthier than non-gluten-free foods? An evaluation of supermarket products in Australia. The British Journal of Nutrition, 114(3), 448–54.
- Missbach, B., Schwingshackl, L., Billmann, A., Mystek, A., Hickelsberger, M., Bauer, G., & König, J. (2015). Gluten-free food database: the nutritional quality and cost of packaged gluten-free foods. PeerJ, 3, e1337.
- Staudacher, H. M., Lomer, M. C. E., Anderson, J. L., Barrett, J. S., Muir, J. G., Irving, P. M., & Whelan, K. (2012). Fermentable carbohydrate restriction reduces luminal bifidobacteria and gastrointestinal symptoms in patients with irritable bowel syndrome. The Journal of Nutrition, 142(8), 1510–8.
Adapted from an article first published in NHD magazine.