Study designs and analytic strategies for environmental and policy research on obesity, physical activity, and diet: recommendations from a meeting of experts.

Numerous authoritative reports have identified environmental and policy interventions as the most promising strategies for creating population-wide improvements in diet, physical activity, and obesity. Yet many methodologic challenges to conducting environmental and policy research must be overcome to enable this area of study to advance. A meeting titled "Study Designs and Analytic Strategies for Environmental and Policy Research on Obesity, Physical Activity, and Diet" was held April 8, 2008. Participants from diverse backgrounds identified priority gaps in knowledge and generated recommendations for promising methods to enhance environmental and policy research related to obesity. Final recommendations were based on a postmeeting participant survey. Existing methods were identified that could be applied to advance the field, including prospective studies, evaluations of natural experiments, and economic studies. Training for investigators in the use of appropriate statistical methods for complex designs and interdisciplinary collaboration were recommended. Methodologic research priorities included the development of measures of policy, health impact assessments, and the investigation of policy adoption and implementation. The results of this conference can be used to improve the quality and quantity of environmental and policy research as well as the translation to action to control obesity.