Evaluation of a Theory-Based Intervention Aimed at Reducing Intention to Use Restrictive Dietary Behaviors Among Adolescent Female Athletes

Objective: To evaluate the effectiveness of a theory-based intervention to reduce the intention to use restrictive dietary behaviors for losing weight among adolescent female athletes involved in aesthetic sports. Design: Cluster-randomized controlled trial. Setting: Aesthetic sport teams of adolescent female athletes aged 12-17 years. Participants: Two teams (n = 37 athletes) in the intervention group and 3 teams (n = 33) in the comparison group. Interventions: The 2 groups received nutrition education during 3 weekly 60-minute sessions. The intervention group was further exposed to a theory-based intervention targeting the specific determinant of intention to use restrictive dietary behaviors for losing weight, namely attitude. Main Outcome Measures: Difference over time between groups in intention to use restrictive dietary behaviors for losing weight and in nutrition knowledge. Analysis: Mixed models for repeated measures. Results: The theory-based intervention contributed to maintaining a low intention of using restrictive dietary behaviors for losing weight over time in the intervention group compared with the comparison group (P < .03). Nutrition knowledge score increased equally in both groups. Conclusion and Implications: Complementing nutrition education with theory-based behavior change intervention may help maintain a low intention of using restrictive dietary behaviors for losing weight among female high school athletes involved in aesthetic sports.