Project Abstract Limited access to food and physical activity (PA) resources as well as poor social and economic neighborhood conditions have been linked to low diet quality, physical inactivity, and elevated body mass index (BMI). Yet, mixed findings may be due to gaps in understanding (1) the root causes of unequal allocation of such neighborhood resources, and (2) the paths by which neighborhood conditions influence obesity. Root causes such as housing policies have received little attention in obesity research and yet this may be critical to addressing the epidemic. A key example is historical ‘redlining,’ where, between the 1930s and 1970s, areas throughout the United States were designated as “high risk” based on the neighborhood’s racial composition. Residents were systematically denied access to home purchasing. Poverty and segregation patterns in redlined areas persisted; yet there is variation in the subsequent demographic shifts that have occurred. Housing discrimination continues and may increase obesity disparities via heightened exposure to obesogenic environments. We seek to address knowledge gaps by estimating longitudinal paths from historical and current racially biased mortgage lending to BMI in a longitudinal cohort of Black and white adults. The project specific aims are to: 1) Determine whether historically redlined neighborhoods have higher levels of obesogenic neighborhood conditions and resident BMI through dietary behaviors and PA than non-redlined neighborhoods (using baseline residential locations,1985–86); 2) Estimate longitudinal paths between changes in historically redlined neighborhoods and BMI through changes in obesogenic neighborhood conditions, dietary behaviors, and PA (using five timepoints of data, 1985–86, 1992–93, 2005–06, 2010–11, and 2015–16); and 3) Estimate longitudinal paths between rates of current place- and race-based biased mortgage lending (data from 1990– 93, 2003–06, 2008–11, and 2013–2016) and changes in BMI, through changes in obesogenic neighborhood conditions, dietary behaviors, PA, discrimination, and homeownership (data from 1985–86, 1992–93, 2005–06, 2010–11, and 2015–16). We achieve these objectives using the Coronary Artery Risk Development in Young Adults Study (CARDIA) which is a longitudinal cohort with diet, PA, environmental, and sociodemographic data collected for 5,115 white and black U.S. adults aged 18-30 years residing in four cities with redlining histories: Birmingham, AL, Oakland, CA, Chicago, IL, and Minneapolis, MN. We will link historic redlining maps and two indices of place- and race-based biased mortgage lending, using mortgage data, to CARDIA participants’ residential locations. We will estimate longitudinal paths from changes in residing in areas that were historically redlined and areas with current biased mortgage lending to BMI changes through dynamic neighborhood conditions, discrimination, homeownership, PA, and dietary behaviors. The results will deliver the...