Is Disordered Eating Related To Muscle-enhancing Supplement Use And Exercise Context in Adolescents?

Abstract

Participation in organized sport at a lower competitive level may protect against disordered eating (DE), whereas exercising in a gym context may increase DE risk. Use of supplements advertised as muscle enhancing is common in both contexts due to the expectancy of performance or appearance enhancement. However, how supplement use (SU) relates to DE dependent on these two exercise contexts in adolescents is not known. PURPOSE: To study how participation in sport or/and a gym context and SU relates to DE in adolescents. METHOD: Participants were 599 boys and 1038 girls enrolled in a RCT to promote a positive body image and prevent DE in high schools. The “Eating Disorder Examination Questionnaire” (EDEQ) short form measured DE. Participants provided information about exercise context (1 = gym + sport, 2 = gym only, 3 = neither sport or gym, 4 = sport only) and SU (1 = protein and creatine (PSU+CSU), 2 = protein only (PSU), and 3 = no SU). ANCOVA was used to examine main and interaction effects of SU and sport context. Effects were considered significant when F test was p = <.05. The analyses were stratified for gender. RESULTS: Among boys, PSU+CSU was associated with higher EDEQ-score (b = 1.31, p < .01). In addition, reporting either sport, gym, or gym + sport context was associated with lower EDEQ-score (b = -1.16, p = .01) in boys. In girls, higher EDEQ-score was associated with reporting gym or gym + sport context (b = .77, p < .01 and b = .68, p = < .01), while higher score was associated with sport context (b = -.33, p = .02). Effects were found for the covariates body mass index (boys, b = 1.05, p < .01, girls, b = .18 p =.01) and studying sport program (boys, b -1.21 p < .01). No effects were found for other covariates (income, physical activity level and immigration status). CONCLUSION: Boys who reported using protein and creatine supplements and girls who exercised in gyms had higher DE. Interestingly, lower DE in boys was related to both sport and/or gym exercise participation compared to boys not reporting participation in either of the two contexts. Attention and preventive actions should be aimed towards girls engaging in gym exercise, and towards boys who consume protein and creatine supplements, and who do not participate in any of the two exercise contexts. Future studies should however examine how other exercise contexts relates to SU and DE.