Approaches to measuring the extent and impact of environmental change in three California community-level obesity prevention initiatives.

Despite growing support among public health researchers and practitioners for environmental approaches to obesity prevention, there is a lack of empirical evidence from intervention studies showing a favorable impact of either increased healthy food availability on healthy eating or changes in the built environment on physical activity. It is therefore critical that we carefully evaluate initiatives targeting the community environment to expand the evidence base for environmental interventions. We describe the approaches used to measure the extent and impact of environmental change in 3 community-level obesity-prevention initiatives in California. We focus on measuring changes in the community environment and assessing the impact of those changes on residents most directly exposed to the interventions.