Appearance-focused social media use contributes to body dissatisfaction and elevated eating disorder (ED) risk in adolescents and young adults. Scalable, digitally delivered interventions targeting social media behaviours alongside psychological risk factors remain limited. This pilot trial evaluated BodyScreen, a 4-week mobile app designed to reduce maladaptive social media engagement while promoting self-esteem and body appreciation. Eighty adolescent and young adult women in Canada aged 15–29 with elevated ED risk participated in a single-arm pilot trial. Assessments were conducted pre- and post-intervention. The primary outcome was ED symptomatology. Secondary outcomes included body dissatisfaction, self-esteem, perfectionism, social media use, psychological adjustment, and quality of life. Linear mixed-effects models examined pre-post changes, and semi-structured interviews assessed user experience. Sixty-eight participants (85%) completed post-intervention assessments. ED symptoms decreased significantly (d = -1.12). Improvements were also observed across secondary outcomes: body dissatisfaction (d = -1.30), self-esteem (d = 0.84), perfectionism (d = -0.85), social media use (d = -0.46), psychological adjustment, and quality of life (d = 0.50). Engagement was high (73% completing ≥70% of exercises), and few negative effects were reported, while usability was moderate. Qualitative feedback highlighted structured daily routines and skill acquisition as facilitators, with repetitive self-monitoring and minor interface challenges as barriers. BodyScreen is a feasible, safe, and promising early intervention for young women at elevated ED risk, particularly those with appearance-motivated social media use. Future trials should include a control group, recruit more diverse samples, evaluate longer-term outcomes, and incorporate qualitative feedback to enhance usability and engagement.
