OBJECTIVES: Childhood obesity is a serious health problem in the United States and worldwide. More than 30 percent of American children and adolescents are overweight or obese. We assessed the effectiveness of childhood obesity prevention programs by reviewing all interventional studies that aimed to improve diet, physical activity, or both and that were conducted in schools, homes, primary care clinics, childcare settings, the community, or combinations of these settings in high-income countries. We also reviewed consumer health informatics interventions. We compared the effects of the interventions on weight-related outcomes (e.g., body mass index [BMI], waist circumference, percent body fat, skinfold thickness, prevalence of obesity and overweight); intermediate outcomes (e.g., diet, physical activity); and obesity-related clinical outcomes (e.g., blood pressure, blood lipids).
DATA SOURCES: We searched MEDLINE®, Embase®, PsycInfo®, CINAHL®, clinicaltrials.gov, and the Cochrane Library through August 11, 2012.
METHODS: Two reviewers independently reviewed each article for eligibility. For each study, one reviewer extracted the data and a second reviewer verified the accuracy. Both reviewers assessed the risk of bias for each study. Together, the reviewers graded the strength of the evidence (SOE) supporting interventions—diet, physical activity, or both—in each setting for the outcomes of interest. We quantitatively pooled the results of studies that were sufficiently similar. Only experimental studies with followup of at least 1 year (6 months for studies in school settings) were included. We abstracted data on comparisons of intervention versus control.
RESULTS: We identified 34,545 unique citations and included 131 articles describing 124 interventional studies. The majority of the interventions (104 studies) were school based, although many of them included components delivered in other settings. Most were conducted in the United States and in the past decade. Results of four studies were pooled for BMI and four for BMI z-score in the school-only setting; results of five school-home studies were pooled for BMI. Other studies tested interventions delivered at home (n=6), in primary care (n=1), in childcare (n=4), and in the community (n=9). Six studies tested consumer health informatics interventions. For obesity prevention, the following settings and interventions showed benefit: school-based—diet or physical activity interventions (SOE moderate); school-based with a home component—physical activity interventions (SOE high) and both diet and physical activity (SOE moderate); school-based with home and community components—diet and physical activity interventions (SOE high); school-based with a community component—diet and physical activity interventions (SOE moderate); community with a school component—diet and physical activity interventions (SOE moderate). The strength of the evidence is either low or insufficient for the remainder of the interventions and settings.
CONCLUSIONS: The evidence is moderate about the effectiveness of school-based interventions for childhood obesity prevention. Physical activity interventions in a school-based setting with a family component or diet and physical activity interventions in a school-based setting with home and community components have the most evidence for effectiveness. More research is needed to test interventions in other settings, such as those testing policy, environmental, and consumer health informatics strategies.