School- and family-based interventions to prevent overweight in children

There have been only a few controlled studies on the prevention of overweight and obesity in children and adolescents. These studies differ in relation to strategy, setting, duration, focus, variables of outcome and statistical power, and therefore do not allow general conclusions to be made about the value of preventive measures. All school-based interventions aimed at the prevention of overweight and obesity show some improvement of health knowledge and health-related behaviours. Short-term effects on nutritional state seem to be more pronounced in girls than in boys. School-based interventions can reduce the incidence of overweight. There is evidence that families of intermediate and high socio-economic status as well as intact families benefit more from treatment than families sharing other characteristics. Selected prevention in obese children is most successful when children are treated together with their parents. However, there are social barriers limiting the success of family-based interventions. Although some positive effects have been reported, simple interventions in a single area (e.g. a school health education programme) are unlikely to work on their own. The development of effective preventive interventions probably requires strategies that affect multiple settings simultaneously. At present there is no concerted action, rather many strategies in health promotion that are followed in isolation. Faced with the epidemic of overweight there is a need for national campaigns and action plans on childhood overweight and obesity. It is tempting to speculate that this strategy will also increase the value of isolated approaches (e.g. in schools and families).