A randomized controlled trial of three school-based programs and a no-intervention control group was conducted to evaluate their efficacy in reducing eating disorder and obesity risk factors.A total of 1316 grade 7 and 8 girls and boys (mean age = 13.21 years) across three Australian states were randomly allocated to: Media Smart; Life Smart; the Helping, Encouraging, Listening and Protecting Peers (HELPP) initiative; or control (usual school class). Risk factors were measured at baseline, post-program (5 weeks later), and at the 6- and 12-month follow-ups.Media Smart girls had half the rate of onset of clinically significant concerns about shape and weight than control girls at the 12-month follow-up. Media Smart and HELPP girls reported significantly lower weight and shape concern than Life Smart girls at the 12-month follow-up. Media Smart and control girls scored significantly lower than HELPP girls on eating concerns and perceived pressure at the 6-month follow-up. Media Smart and HELPP boys experienced significant benefit on media internalization compared with control boys and these were sustained at the 12-month follow-up in Media Smart boys. A group × time effect found that Media Smart participants reported more physical activity than control and HELPP participants at the 6-month follow-up, while a main effect for group found Media Smart participants reported less screen time than controls.Media Smart was the only program to show benefit on both disordered eating and obesity risk factors. Whilst further investigations are indicated, this study suggests that this program is a promising approach to reducing risk factors for both problems.