Fueling Your Gut with Carbohydrates
Content:
Practical takeaways for athletes and weekend warriors.
By: Renee Korczak Ph.D., RDN, CSSD, LD Premier Nutrition, LLC
Instagram: @premierdietitiannj
Facebook: Premier Nutrition, LLC
Web: premierdietitian.com
FUELING YOUR GUT WITH CARBOHYDRATES: An Update on the Science for Competitive Athletes and Weekend Warriors.
Carbohydrates, along with protein and fat, are major macronutrients required in the diet daily. For an average person on a 2,000 calorie per day diet, it is recommended to consume between 45-65% of those calories from nutrient-dense carbohydrate foods (1). For active adults and competitive athletes, carbohydrate recommendations are even more personalized and would consider a person’s body weight, type and duration of exercise training, intensity, or participation in team sport.
For example, certain athletes who participate in team sports may require between 500-800 grams of carbohydrate per day to help fuel and prepare for competition (for context, 1 slice of whole wheat bread provides about 15 grams of carbohydrate); so yes that’s a lot of carbohydrate! Including high amounts of carbohydrate in the diet, helps promote carbohydrate availability for working muscles and ensures that fuel targets are met for performance (2).
Due to the demand for carbohydrates in the active population and the role that they play in providing energy for the brain, central nervous system and working muscles, carbohydrates have received considerable attention in the sports nutrition world (2). Nondigestible carbohydrates including prebiotic fibers and resistant starches are also of interest, due to their ability to help support microbial diversity in the gut, and to support overall gut health (3).
The gut is a very active organ and regular exercise, and training plays a beneficial role by affecting the structure and diversity of the gut microbiota (4). For example, research in athletes have reported higher gut microbiota diversity, along with a higher amount of bacteria that produce the beneficial metabolite called butyrate, compared to sedentary individuals (5-6). Prebiotics are non-digestible carbohydrates that can pass through the digestive system, until they hit the colon where they are fermented by naturally present bacteria to produce metabolic by-products (SCFAs), including acetate, propionate, and butyrate. A number of foods and beverages contain prebiotic fibers including oats, chickpeas, asparagus, leeks, chicory, garlic, artichoke, onion and some functional prebiotic beverages.
While prebiotic fiber is important and has many benefits for gut health, some athletes may follow a low-fiber plan prior to exercise, training or a major event or competition. This is because ingestion of too much fiber close to a workout may cause gastrointestinal disturbances. Endurance athletes particularly experience GI disturbances (7), due to reduced blood flow to the gastrointestinal tract over time, resulting in the depletion of energy (ATP), stress, and low oxygen levels (3). In response to this, the gastrointestinal tract releases signals that are associated with gastrointestinal disturbances (3). This is particularly the case when adequate nutrition and rest are not followed post-workout (3). However, this is not the case for all athletes; especially if habitual fiber intake is well tolerated and adequate during training and days leading up to a major competition or event.
While research in this area continues, active individuals and athletes should consider that their gut is an active organ that needs to be properly nourished with nutrient-dense carbohydrate choices for beneficial effects on performance. Prebiotics can help alter the gut microbiota, with potential benefits for athletic performance (3).
Practical takeaways for athletes and weekend warriors.
Here are some practical takeaways for athletes and weekend warriors to help optimize performance and train your gut:
Think about including nutrient-dense carbohydrates, including prebiotics, in your diet such as whole grains, a variety of fruits, veggies, and starches
Consider working with a registered dietitian (RD) to help design an eating plan that fuels optimal performance during the pre-exercise, during exercise and post-exercise recovery period
Troubled by GI disturbances on occasion? Modify your diet during training and work with a dietitian to help customize a plan that minimizes disturbances and symptoms of it during competition day
Are you a low-fiber consumer to begin with? Consider introducing one fibrous food or beverage at a time to give your gut time to acclimate to these new foods or beverages
Understand that each athlete and person have a unique GI tract and finding a nutrition regimen that works best may take adaptation and time.
References:
Institute of Medicine: Dietary Reference Intakes. Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein and Amino Acids. Washington, DC: National Academy Press; 2002.
Thomas D.T., Erdman K.A., and Burke L.M. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance J Acad Nutr Diet 2016; 116(3): 501-528.
Hughes R.L., Holscher H.D. Fueling Gut Microbes: A Review of the Interaction between Diet, Exercise and the Gut Microbiota in Athletes Adv Nutr 2021; 12: 2190-2215.
West N.P. et al. Butyrylated starch increases colonic butyrate concentration but has limited effects for immunity in healthy physically active individuals. Exercise Immunol. Rev 2013; 19: 102-119.
Jang L.G., Geunhoon C, Sung-Woo K, Byung-Yong K, Sunghee L, Park H. The combination of sport and sport-specific diet is associated with characteristics of gut microbiota: an observational study Journal of the International Society of Sports Nutrition 2019; 16:21.
Rios J.L., Bomhof M.R., Reimer R.A., Hart D.A., Collins K.H., Herzog W.H. Protective effect of prebiotic and exercise intervention on knee health in a rat model of diet-induced obesity Nature 2019; 9:3893.
Estaki M, et al. Cardiorespiratory fitness as a predictor of intestinal microbial diversity and distinct metagenomic functions Microbiome 2016; 4(1): 42.