A Cochrane review [Abstract] 1 included 55 studies. The majority of studies targeted children aged 6-12 years. The meta-analysis included 37 studies of 27,946 children and demonstrated that programmes were effective at reducing adiposity.
Overall, children in the intervention group had a standardised mean difference in adiposity (measured as BMI or zBMI) of -0.15kg/m2 (95% confidence interval (CI): -0.21 to -0.09). Intervention effects by age subgroups were -0.26kg/m2 (95% CI:-0.53 to 0.00) (0-5 years), -0.15kg/m2 (95% CI -0.23 to -0.08) (6-12 years), and -0.09kg/m2 (95% CI -0.20 to 0.03) (13-18 years). Heterogeneity was apparent in all three age groups and could not explained by randomisation status or the type, duration or setting of the intervention. Only eight studies reported on adverse effects and no evidence of adverse outcomes such as unhealthy dieting practices, increased prevalence of underweight or body image sensitivities was found.
A systematic review 2 including 64 studies with a total of 23172 subjects was abstracted in DARE. 21 % of the prevention programs seeking to produce weight gain prevention effects produced significant prevention effects that were typically pre- to post effects. Larger effects emerged for programs that targeted children and adolescents (vs. preadolescents) and females, programs that were relatively brief, programs that solely targeted weight control versus other health behaviors (e.g., smoking), programs evaluated in pilot trials, and programs wherein participants must have self-selected into the intervention. Other factors, including mandated improvements in diet and exercise, sedentary behaviour reduction, delivery by trained interventionists, and parental involvement, were not associated with significantly larger effects.
Comment: The quality of evidence is downgraded by study quality (unclear allocation concealment) and by indirectness (the majority of studies were short-term).
Primary/Secondary Keywords