Study selection
Randomised controlled trials (RCTs) or controlled trials that evaluated school-based programmes aimed at addressing overweight and obesity in pre-adolescent and adolescent schoolchildren of any nationality who were of normal body mass index (BMI), overweight or obese were eligible for inclusion. "Fatness" was classified using criteria of the International Obesity Task Force or by country-specific norms. Eligible interventions were those with a specific approach to increase physical activity, improve dietary behaviours, modify poor exercise or dietary behaviours, or a combination of these. Outcomes of interest were BMI, waist girth, percentage body fat and triceps skinfold.