Daniel Rodriguez and Kelly Evenson–Co-PIs. Higher weights in children have increased significantly over the past 20 years, while sedentary behaviors have concurrently increased. By limiting the opportunities for being physically active in every day life and making excessive calories available, particularly in the form of energy dense snacks, contemporary neighborhoods and the built environment are believed to play a causal role in the obesity epidemic. As a result, researchers and policy makers are examining the characteristics of the built and natural environments that can be supportive of active living and healthy eating. To date, most research in this area has relied on self-reports of where physical activity (PA) occurs. Few studies have examined whether food exposures influence consumption. Accurate knowledge of where people are being physically active and what food sources they are exposed to is critical for examining associations between the built environment, PA, and diet, particularly with a view towards developing policy recommendations that could have a population level impact on the obesity epidemic. The proposed study, funded by the National Institutes of Health and the RAND Corporation, will build on information collected in Rodriguez and Evenson’s previous study, “Community Characteristics and Physical Activity among Adolescent Girls,” which was an ancillary study to TAAG, Trial of Activity of Adolescent Girls. In the baseline study they found associations between neighborhood characteristics such as parks and playgrounds and physical activity, but could not determine if girls were active in these settings or whether increased levels of physical activity were due to community norms. In this new project, they will follow the same girls from the Minneapolis and San Diego TAAG sites and identify where they go when they are not in school or home by using global positioning system (GPS), a device worn on the wrist or hip. GPS will be combined with accelerometry and self-reports of food purchases and consumption so that they will be able to determine the context in which physical activity and eating occur. For more information contact Daniel Rodriguez at 919-962-4763 or at email@example.com. Kelly Evenson may be reached at 919-966-4187 or at firstname.lastname@example.org.