The Electronic Games to Aid Motivation to Exercise (eGAME) study was a randomised controlled trial to evaluate the effect of active video games on body composition, physical activity and cardiovascular fitness in overweight and obese children in New Zealand. The study recruited 322 children aged 10–14 years who regularly used traditional sedentary video games and randomly allocated them to a 24-week active video games intervention (n=160) or control (n=162). At 24 weeks, statistically significant overall treatment effects were observed favouring the intervention group for body mass index, body mass index z-score and percentage body fat. Regression analyses revealed that the interaction operated consistently across important subgroups (by ethnicity, sex, and cardiovascular fitness).