An Online Nutrition Education Program Targeting Intentions and Related Determinants Towards Dietary Supplement Use: An Application of the Theory of Planned Behavior

Background/Objectives: Dietary supplement use among varsity athletes is influenced by various psychological and social factors, yet there is limited evidence on the effectiveness of educational interventions in influencing these determinants. The aim of this study was to determine the effects of an online nutrition education program on improvements in intentions and related determinants towards the use of dietary supplements in varsity athletes at the University of Guelph in Canada. The theory of planned behavior served as the theoretical framework for examining these determinants as predictors of behavior change. Methods: A randomized wait-list controlled trial was conducted on a total of 30 varsity athletes, randomized into experimental (n = 18) and control (n = 12) groups. The experimental group received access to an online nutrition education program focused on sports nutrition and dietary supplements, while the control group did not have access during the study. Results: There was a significant (p < 0.05) intervention effect on varsity athletes' attitudes (Mean1_(control) = 13.17; Mean1_{(experimental)} = 13.56; Mean2_(control) = 13.92; Mean2_{(experimental)} = 12.11), perceived behavioral control (Mean1_(control) = 15.92; Mean1_{(experimental)} = 16.11; Mean2_(control) = 16.33; Mean2_{(experimental)} = 18.39), and intentions (Mean1_(control) = 12.5; Mean1_{(experimental)} = 12.89; Mean2_(control) = 11.58; Mean2_{(experimental)} = 9.44) towards dietary supplement use. No significant changes were made to descriptive and injunctive norms. Conclusions: These findings suggest that this nutrition education program significantly improved intentions and related determinants towards dietary supplement use in varsity athletes. The absence of a successful change in subjective norm should be a focus for similar future interventions.