Supplementation of Japanese elite athletes for the Paris 2024 Olympic games: differences according to nutritional support experience

Background Supplements are popular among athletes. To prevent anti-doping rule violations, athletes, registered dietitians, and support professionals must assess the safety, efficacy, and necessity of supplements. However, the relationship between experience with receiving nutritional support and supplement intake has not yet been examined. Objective In this study, we aimed to investigated differences in supplement use according to nutritional support experience using the Australian Institute of Sport classification system. Methods A self-administered questionnaire was completed by 800 athletes representing Japan at the Paris 2024 Olympic Games (including candidates). The survey assessed supplement intake over the past year, nutritional support experience, and knowledge and practices regarding supplements and hydration. Results Overall, 92.3% of athletes used supplements, with a higher percentage among those who had nutritional support experience ( p < 0.01). Among athletes who consumed group A sports foods (evidence-based supplements), the intake rates were higher among those with nutritional support experience than among those without nutritional support experience ( p < 0.01). Even after adjusting for age and sex, nutritional support experience was associated with total supplements and sports foods intake. Conclusion Nutritional support experience appears to be associated with the intake of supplements, particularly sports foods. Although limited to associations, these findings highlight the need for dietitians to collaborate with multidisciplinary staff when providing athletes with comprehensive, evidence-based education on supplement efficacy and safety.