Programs to Reduce Childhood Obesity Seem to Work, Say Cochrane Reviewers

Abstract

OBESITY PREVENTION PROgrams for children have produced mixed results that could lead one to wonder if they are effective. A recent review of the literature suggests such programs can work, but an optimal course of action remains elusive. The authors of a Cochrane Collaboration meta-analysis of 55 studies assessing educational, behavioral, and health promotion interventions in general populations of children aged 0 to 18 years, including children who were obese, found that these interventions reduced the children’s body mass index (BMI) by an average of 0.15 kg/ m. In an average child of elementary school age (around 10 years) with a BMI of 18.2 kg/m, such a reduction would be the equivalent of a 0.8% weight reduction (Waters E et al. Cochrane Database Syst Rev. 2011;12:CD001871). Such a modest weight loss suggests these interventions are not having much effect, but Elizabeth Waters, MPH, DPhil, a coauthor of the Cochrane review and chair of child public health in the Melbourne School of Population Health, UniversityofMelbourne inAustralia, said via e-mail that a BMI reduction of this magnitude in a population-wide metaanalysis is significant. “Effect sizes of this magnitude are to be expected because these were prevention interventions rather than treatment interventions with children,” said Waters, noting that the interventions were mainly over short periods—12 months or less. “While these effect sizes may appear small, they represent important reductions at a population level if sustained over several years.” Waters cited previous research suggesting a modest 1% drop in BMI in US adults would allow the country to avoid up to 2.4 million new cases of diabetes, up to 1.7 million cases of cardiovascular disease, and up to 127 000 cases of cancer (Wang YC et al. Lancet. 2011;378[9793]:815-825). The Cochrane authors found some programs were effective at reducing adiposity but others were not, and in those successfully showing weight loss, there