Effectiveness of a brief school-based body image intervention ‘Dove Confident Me: Single Session’ when delivered by teachers and researchers: Results from a cluster randomised controlled trial

This study evaluated a 90-min single session school-based body image intervention (Dove Confident Me: Single Session), and investigated if delivery could be task-shifted to teachers. British adolescents (N = 1707; 11-13 years; 50.83% girls) participated in a cluster randomised controlled trial [lessons as usual control; intervention teacher-led (TL); intervention researcher-led (RL)]. Body image, risk factors, and psychosocial and disordered eating outcomes were assessed 1-week pre-intervention, immediate post-intervention, and 4-9.5 weeks follow-up. Multilevel mixed-models showed post-intervention improvements for intervention students relative to control in body esteem (TL; girls only), negative affect (TL), dietary restraint (TL; girls only), eating disorder symptoms (TL), and life engagement (TL; RL). Awareness of sociocultural pressures increased at post-intervention (TL). Effects were small-medium in size (ds 0.19-0.76) and were not maintained at follow-up. There were no significant differences between conditions at post or follow-up on body satisfaction, appearance comparisons, teasing, appearance conversations and self-esteem. The intervention had short-term benefits for girls' body image and dietary restraint, and for eating disorder symptoms and some psychosocial outcomes among girls and boys. A multi-session version of the intervention is likely to be necessary for sustained improvements. Teachers can deliver this intervention effectively with minimal training, indicating broader scale dissemination is feasible. Trial registration: ISRCTN16782819.