Can targeted policies reduce obesity and improve obesity-related behaviours in socioeconomically disadvantaged populations? A systematic review.

This review synthesized evidence from controlled studies pertaining to the impact of targeted policies on anthropometric, dietary and physical activity outcomes amongst socioeconomically disadvantaged children and adults. Preferred Reporting Items for Systematic Reviews and Meta-Analyses-Equity guidelines were followed. Eligible studies were published from 2004 to August 2015 and examined the impact of targeted policies on anthropometric, dietary and physical activity outcomes amongst socioeconomically disadvantaged populations. Twenty articles (18 studies) were included. Eight studies examined organizational policies within multi-component interventions in schools. Common elements of successful policy-containing interventions included nutritional standards, enhancements to physical education, additional physical activity opportunities, school self-assessments, and nutrition and physical activity education. Of the 10 studies of government policies, policies providing information/education and fruit and vegetable subsidies had positive impacts amongst children, but no impact amongst adults. Policies involving changes to built environments yielded nearly uniformly null findings in children and adults. Overall, the largest quantity of high-quality evidence of effectiveness was for comprehensive interventions that included school policies, and government policies targeting disadvantaged children in schools. None of the government policies targeting disadvantaged adults proved effective. Interventions during childhood may ameliorate negative obesity-related manifestations of socioeconomic disadvantage. Gaps in knowledge remain surrounding effective policies in adults, adolescents and very young children.