Socioeconomic status moderates the effect of physical education on overweight and obesity in children: a quasi-experimental trial

This study aimed to estimate the effects of an intensive school-based physical education intervention on the risk of developing overweight or obesity in primary school students when accounting for the moderating role of socioeconomic status. This quasi-experimental trial included data from primary school students participating in an intensive physical education program comprising 4.5 h of weekly physical activity compared to 1.5 h per week in the control group. Socioeconomic status was estimated by maternal education. The study outcome was overweight or obesity status determined by longitudinal measures of body mass index over 4.5 years. Intervention effects and the moderating role of socioeconomic status were estimated using multilevel mixed-effects logistic models. We included data from 588 children in the intensive physical education group and 415 children in the control group (52.9% female; mean [SD] age = 8.5 [1.4] years). There was a significant 3-way interaction between intervention group, socioeconomic status, and time (p = 0.018). Within the control group, children from the low socioeconomic strata had a greater probability of being overweight or obese from 36 months onward compared to children from the high socioeconomic strata. The physical activity intervention reduced the risk of overweight or obesity among children from the low socioeconomic strata; after 4.5 years, the risk reduction (95% CI) was 11.4 (2.4 to 20.4)%. CONCLUSION: A school-based physical activity intervention, delivered through a physical education program, effectively reduces overweight and obesity risk in disadvantaged primary school students and may address some of the adverse health-related impacts of living with low socioeconomic status. WHAT IS KNOWN: • School-based physical activity programs offer promising solutions for improving health-related physical activity in children. However, the impact of socioeconomic context on the effectiveness of these programs is unclear. WHAT IS NEW: • An intensive school-based physical activity intervention effectively reduces overweight and obesity risk in disadvantaged primary school students and may address some of the adverse health-related impacts of living with low socioeconomic status.