Childhood obesity policy research and practice: evidence for policy and environmental strategies.

Investigators developed a review system to evaluate the growing literature on policy and environmental strategies to prevent childhood obesity. More than 2000 documents published between January 2000 and May 2009 in the scientific and grey literature were identified (2008-2009) and systematically analyzed (2009-2012). These focused on policy or environmental strategies to reduce obesity/overweight, increase physical activity, and/or improve nutrition/diet among youth (aged 3-18 years). Guided by the RE-AIM (Reach, Effectiveness, Adoption, Implementation, and Maintenance) framework, investigators abstracted studies of 24 intervention strategies and assessed evidence for their effectiveness (i.e., study design, intervention duration, and outcomes) and population impact (i.e., effectiveness and reach--participation or exposure, and representativeness) in 142 evaluation study groupings and 254 associational study groupings (n=396 groupings of 600 peer-reviewed studies). The 24 strategies yielded 25 classifications (school wellness policies yielded nutrition and physical activity classifications): 1st-tier effective (n=5); 2nd-tier effective (n=6); "promising" (n=5); or "emerging" (n=9). Evidence for intervention effectiveness was reported in 56% of the evaluation, and 77% of the associational, study groupings. Among the evaluation study groupings, only 49% reported sufficient data for population impact ratings, and only 22% qualified for a rating of high population impact. Effectiveness and impact ratings were summarized in graphic evidence maps, displaying effects/associations with behavioral and obesity/overweight outcomes. This paper describes the results and products of the review, with recommendations for policy research and practice.