Grant Number:	2R01CA228058-06A1 Interpret this number
Primary Investigator:	Datar, Ashlesha
Organization:	University Of Southern California
Project Title:	The Impact of Improvements in Built and Social Environments and Housing on Obesity in Public Housing Residents: Evidence From a Natural Experiment
Fiscal Year:	2026

ABSTRACT Obesity continues to increase in disadvantaged populations. Neighborhood revitalization efforts in low- income communities have sought to reverse these trends. One such effort is currently underway in Watts, Los Angeles, where the Jordan Downs (JD) public housing site, an obsolete project housing low-income Hispanic and Black residents, is being redeveloped. The redevelopment is building replacement housing for all original tenants, doubling housing capacity to allow new mixed-income residents, and overhauling the built environment. The redevelopment avoids resident displacement and has created quasi-experimental variation in the timing and “dose” of residents’ exposure to the redevelopment components. In 2018, the parent grant (R01CA228058) initiated a cohort study to examine the JD redevelopment’s impact on residents’ body mass index and obesity in its early years, explore potential explanations for any observed effects, and assess heterogeneity in effects. We recruited a cohort of 888 adults from JD and two comparison public housing sites in Watts and followed them longitudinally, with two baseline (2018-19, 2019-20) and two follow-up waves (2020-21, 2021-22). During the follow-up years, about 1/3rd of the site was redeveloped. The parent study found – (a) alarmingly high rates of overweight or obesity (80%) in the cohort, (b) substantial heterogeneity in residents’ reported barriers to healthy eating and exercising, despite similar socioeconomic background and neighborhood environment, leading to variability in who benefited from the redevelopment; and (c) a 14% decline in abdominal obesity among JD residents with highest exposure that likely operated via lower added sugar intake. However, these effects may have been dampened by the Covid-19 pandemic that coincided with the followup waves. Also, it is unclear whether these changes are temporary (e.g. due to the novelty) or long-lasting (e.g. due to habit formation). This renewal application proposes to follow the existing cohort through the remaining 2/3rds of the redevelopment with 4 additional rounds of data collection to address the following aims – (1) Examine the redevelopment’s impact on residents’ obesity through the remainder of the redevelopment. As more JD households receive higher “doses” of the redevelopment, we will examine if these effects fade, persist, or become more widespread. (2) Evaluate the continuity of previously observed behavioral pathways and identify emerging ones through the remainder of the redevelopment. And (3) Examine how differences in building design and resident mix influence obesity-related behaviors and risk factors. The redevelopment includes several phases that vary in building design and resident mix, creating an opportunity to test novel hypothesis about their effects on obesity and related behaviors. This study will have a high impact because it builds on a well-established cohort and community partnerships to study a comprehensive community intervention in a high-risk population using rigorous methods, novel hypotheses, and a strong interdisciplinary research team.