Body image as a moderator of the association between addictive social media use and orthorexia nervosa tendencies in physically active university students

Background Social media may contribute to orthorexia nervosa tendencies through exposure to idealized health, fitness, nutrition, and appearance-related content. This study examined whether body image moderated the association between addictive social media use and orthorexia nervosa tendencies among physically active university students. Methods This cross-sectional study included 350 physically active university students aged 18–23 years who reported exercising at least once per week. Participants completed the Bergen Social Media Addiction Scale, the Turkish Düsseldorf Orthorexia Scale, and the Body Cathexis Scale. Pearson correlations and moderation analysis using Hayes’ PROCESS Model 1 were conducted, controlling for the primary demographic and exercise-related covariates, with additional lifestyle variables examined in a fully adjusted sensitivity model. Results Addictive social media use and body image were not independently associated with orthorexia nervosa tendencies. In the primary parsimonious model, the interaction between addictive social media use and body image was not statistically significant ( B = −0.004, p = 0.149) and explained an additional 0.6% of the variance. In a fully adjusted sensitivity model, the interaction was statistically significant ( B = −0.012, p < 0.001) and accounted for an additional 5.1% of the variance. Thus, the primary moderation hypothesis was not supported, and the significant interaction observed in the fully adjusted model should be regarded as specification-sensitive. Conclusion The primary moderation hypothesis was not supported in the parsimonious model. A significant interaction emerged only in the fully adjusted sensitivity model, indicating that the observed moderation pattern was dependent on covariate specification. Accordingly, this finding should be interpreted cautiously and requires confirmation in future longitudinal studies.