Assessing impacts of redeveloping public housing communities on obesity in low-income minority residents: Rationale, study design, and baseline data from the Watts Neighborhood Health Study

INTRODUCTION: Obesogenic built- and social-environments in low-income and minority communities are often blamed for the higher rates of obesity in this population, but existing evidence is based largely on observational studies. This study leverages a natural experiment created by the redevelopment of a public housing community to examine the impact of major improvements to the housing, built, and social environments on obesity among residents. METHODS/DESIGN: The study design is a natural experiment where residents from the redeveloped community (treatment group) will be compared to those from a similar community (control group) in terms of their pre/post changes in primary outcomes using annual longitudinal data on a cohort of residents. Quasi-experimental variation in the timing of exposure to various redevelopment components within the treated community will be further leveraged within a stepped-wedge research design to assess the impact of the redevelopment components. Primary outcome measures include body mass index, overweight, and obese status. RESULTS: A cohort of 868 adults and 704 children (ages 2–17 years) was recruited during 2018–2019 with up to two waves of baseline data. At baseline, the prevalence of obesity (overweight or obesity) was 57.2% (81.3%) in adults and 33.1% (52.4%) among children, with no significant differences by treatment status. No differential trends in primary outcomes were observed by treatment status during the two years of baseline. DISCUSSION: This natural experiment study offers a unique opportunity to assess whether improvements to housing, built, and social environment in low-income minority communities can lead to reductions in obesity.