Fourteen studies (n=12,840) were included:12 RCTs (n=8,925) and 2 non-randomised controlled trials (n=3,915).
Studies that targeted high-risk groups.
The ‘Keil Obesity Prevention Study’ evaluated an exercise programme for children and home visit support for parents, while the El Paso Catch study targeted American-Indian children aged 8 to 10 years. Both demonstrated a positive effect on overweight (statistical results not reported). In contrast, the ‘Pathway’ study (that also targeted American-Indian children) and an obesity programme for inactive girls called ‘New Moves’ did not demonstrate significant effects.
Studies that aimed to increase physical activity.
Two studies demonstrated a significant effect on the prevalence of obesity (statistical results not reported): the ‘Medical College of Georgia FitKid Project’ which involved a healthy snack, physical activity and coaching, and a ‘Dance for Health’ programme. Two studies did not demonstrate a significant effect on overweight: the ‘Promoting lifestyles activities in youths’ and the ‘New Moves’ studies.
Studies that aimed to decrease physical inactivity.
The ‘San Jose’ and the ‘Planet Health’ studies both encouraged children to reduce the amount of time spent in front of the TV, and both reported positive effects on overweight.
Studies that focused on nutrition.
One study aimed to reduce the intake of carbonated drinks: ‘The Christchurch obesity prevention projects in schools’. However, no significant difference in body mass index was observed between the intervention and control groups.
Studies that focused on physical activity and diet.
Six studies aimed to increase physical activity and improve diet: the ‘Planet Health’ study and ‘Keil Obesity Prevention Study’ demonstrated at least some positive effects, whereas the ‘Active Programme Promoting Lifestyle in Schools’, the ‘Be Smart’, the ‘Pathway’ and the ‘Nebraska’ studies did not have a significant effect on overweight.