Obesity in children. Part 2: Prevention and management.

Can obesity be prevented? A meta-analysis and Cochrane systematic review of controlled interventions to prevent childhood obesity published up to 2005 identified 61 and 22 studies, respectively. 3 Most studies found no strong evidence that interventions prevented weight gain or obesity, and many studies were limited in design, duration, or analysis. An update of the Cochrane review will be published in 2009. The 2005 Cochrane review concluded that comprehensive strategies that deal with diet and physical activity, interventions with psychosocial support, and those that involved environmental change may help prevent obesity. The meta-analysis concluded that most (79%) of the large number of trials aimed at preventing childhood obesity found no effect on weight gain. The investigators pooled all studies (despite the varied types of intervention and populations) in one large meta-analysis and found a “trivial” beneficial effect on average, but marked heterogeneity between studies. In contrast to these broad reviews of all interventions, a systematic review of controlled studies with interventions to reduce sedentary activities found that such interventions consistently reduced weight in children. A systematic review of controlled trials to promote physical activity found some evidence of effect on activity levels for environmental interventions and those targeted at children from low socioeconomic backgrounds. Multicomponent interventions (interventions involving school or education, family, the environment, or policy changes) increased physical activity in adolescents. The modest effectiveness of programmes aimed at individual change to prevent obesity is similar to that found for other health behaviours. Little research has evaluated the effect of interventions at the societal and political levels to prevent obesity. SOURCES AND SELECTION CRITERIA