Total fermentable oligo‐, di‐, monosaccharides and polyols intake, carbohydrate malabsorption and gastrointestinal symptoms during a 56 km trail ultramarathon event

Aims To explore the relationship between nutritional intake, fermentable oligo‐, di, monosaccharides and polyols, and carbohydrate malabsorption, with gastrointestinal symptoms during a 56 km trail ultramarathon event and identify differences in nutritional intake between runners with severe and non‐severe gastrointestinal symptoms. Methods Forty‐four ultramarathoners recorded and self‐reported dietary intake 3 days before, morning of, and during the ultramarathon with gastrointestinal symptoms obtained retrospectively and nutrient analysis via FoodWorks. Carbohydrate malabsorption was determined via breath hydrogen content pre‐ and post‐race. Spearman's rank‐order and Mann–Whitney U‐tests were used to identify relationships and differences between groups. Results Total fermentable oligo‐, di, monosaccharides and polyols intake were not associated with gastrointestinal symptoms, but weak associations were observed for lower energy (rs = −0.302, p = 0.044) and fat intake (rs = −0.340, p = 0.024) 3 days before with upper gastrointestinal symptoms and higher caffeine intake 3 days before with overall gastrointestinal symptoms (rs = 0.314, p = 0.038). Total fermentable oligo‐, di‐, monosaccharides and polyols intake and breath hydrogen were not different between those with severe versus non‐severe symptoms (p > 0.05). Although those with severe symptoms had higher caffeine (p = 0.032), and total polyols intake (p = 0.031) 3 days before, and higher % energy from fat (p = 0.043) and sorbitol intake (p = 0.026) during the race, and slower ultramarathon finish times (p = 0.042). Conclusion Total fermentable oligo‐, di‐, and monosaccharides intake and carbohydrate malabsorption were not associated with gastrointestinal symptoms. Additional research on the effect of fat, caffeine, and polyol intake on exercise‐associated gastrointestinal symptoms is warranted and presents new nutritional areas for consideration when planning nutritional intake for ultramarathoners.