Effectiveness of a primary school-based intervention to reduce overweight

Objectives. The purpose of this study was to evaluate the effect of a school-based intervention program to reduce overweight and improve fitness in primary school children. Methods. A cluster randomized controlled design was used over one school year with schools as unit of randomization. In total 20 schools and 2,622 children aged 6-12 years (grades 3-8) from multi-ethnic, low income inner-city neighbourhoods in Rotterdam, Netherlands, participated. The intervention, named Lekker Fit! (Enjoy being fit!) was a multi-component intervention based on behavioural and ecological models. Main components of the intervention are the implementation of three physical education (PE) sessions a week by a professional PE teacher, additional sport and play activities outside school hours and an educational program. Main primary outcome measures were weight status, body mass index (BMI), waist circumference and fitness (20 m shuttle run). Results. Significant positive intervention effects were found for percentage overweight children (OR 0.53; 95% CI 0.36-0.78), waist circumference (-1.29 cm; 95% CI -2.16 to -0.42 cm) and 20 m shuttle run (0.57 laps; 95% CI 0.13-1.01 laps) among pupils of grades 3-5 (6-9-year olds). The prevalence of overweight in grades 3-5 increased by 4.3% in the control group and by 1.3% in the intervention group. No significant effects were found for BMI or for grades 6-8 (9-12-year olds). Conclusions. Our results provide evidence for the effectiveness of the multi-component intervention Lekker Fit! among pupils of grades 3-5 and adds to the growing body of evidence that school-based programs with a focus on PA are most effective in reducing childhood obesity. [ISRCTN84383524]