The obesity epidemic disproportionately affects the 1.2 million U.S. households living in public housing, where nearly 50% of adults are obese and have a two-fold greater risk of hypertension. Using an ecologic framework, we propose that neighborhood social network factors likely promote unhealthy lifestyle behaviors that contribute to this disparity. The overall objective of this proposal is to identify social network factors tha promote healthy diet, physical activity and healthy weight among public housing residents. We focus on the social network - the connections among people within a community - as theoretical work suggests that social networks have an important influence on health behaviors. However, no previous studies have examined lifestyle behaviors in a social network analysis or targeted these behaviors with a social network intervention. We will explore three aims: 1) To characterize the relationship between the social network and obesity / lifestyle behaviors of 500 adults living in public housing developments in Baltimore, MD; 2) To assess if an interaction between the social network and built environment exists and how such an interaction influences the lifestyle behaviors among public housing residents; and 3) To develop a social network intervention to facilitate lifestyle behavior change and pilot test it in residents of public housig developments as in Baltimore, MD. The candidate's long-term career goal is to improve the health of at-risk populations by preventing and treating obesity and cardiovascular disease (CVD). She completed a Clinical Research Fellowship in General Internal Medicine (GIM) at Johns Hopkins, and joined the GIM faculty as an Assistant Professor at Johns Hopkins in July 2012. She has laid out a career development plan to enhance her skills in advanced statistical methods, social network analysis, and behavioral theory. She has also assembled a core mentorship team along with a multidisciplinary advisory committee to support her research and career development. Her core mentorship team is headed by her primary mentor, Dr. Jeanne Clark, Professor of Medicine and Epidemiology, who has extensive experience in mentoring and clinical trials for the prevention and treatment of obesity. This core team also includes Dr. Carl Latkin, Professor of Public Health with expertise in social networks, and Dr. David Levine, Professor of Medicine with expertise in community-based participatory research and CVD risk reduction. In year 5, the results from this work will lead to an R01 application to conduct a randomized controlled trial testing the effect of the social network intervention on healthy lifestyle behavior change that promotes and sustains a healthy weight among the high-risk public housing population.