A dismantling study of body dissatisfaction prevention was conducted. Adolescent girls (N = 260) were randomly allocated to a media literacy (Happy Being Me – Media Literacy) or appearance comparison (Happy Being Me – Appearance Comparison) intervention or healthy eating behaviour control (Happy Being Me – Healthy Eating Behaviour) condition. In the Happy Being Me – Appearance Comparison condition, improvements from baseline to post-programme and follow-up for upward appearance comparison and fear of negative appearance evaluation were observed. In the Happy Being Me – Media Literacy condition, improvements were observed from baseline to post-programme for upward appearance comparison and realism scepticism. Findings were similar in a high-risk subsample and overall are moderately supportive of appearance comparison-based interventions, but less supportive of a stand-alone media literacy intervention.