The theme of the Tulane University Prevention Research Center (TU-PRC) for the next five years will be the lmpact of the Physical and Social Environment on Obesity. Examples of potentially important physical and social environmental factors include: the availability of parks, the availability of healthy and unhealthy foods, and organized community activities for youth. A full research agenda has been developed with community partners that outlines categories of studies and examples of specific studies consistent with this theme. These studies include both determinant research and intervention research. The target population for the TU-PRC will be people in the City of New Orleans, particularly those of low income, most of whom are African-American. The TU-PRC will closely coordinate its prevention research with the newly-funded New Orleans Step Together New Orleans (the local STEPS to a HealthierUS project). The proposed Core Research Project will use community-based participatory research methods and will involve an evaluation of an intervention based on lay health advisors to modify the neighborhood environment to support increased physical activity. Besides the prevention research itself, TU-PRC activities include: community collaboration; communication and dissemination of information about center activities to researchers, policy-makers, and community members; and training for researchers, practitioners, and community members. TU-PRC projects and activities will be developed in partnership with a Community Advisory Board composed of representatives of local organizations and communities.