A natural experiment: The opening of a supermarket in a public housing community and impacts on children's dietary patterns.

Objective: The aim of the present study is to utilize a natural experiment and examine changes in dietary patterns of predominantly low-income, racial and ethnic minority children who live in a public housing community following the opening of a new supermarket. Methods: Data comes from the Watts Neighborhood Health Study (WNHS), an ongoing study in South Los Angeles, United States, that follows residents of Jordan Downs, a public housing community undergoing redevelopment. Surveys were administered to children aged 9-17 years (n = 297), as well as an adult in the household. The second baseline data collection was conducted June-December 2019, and follow-up was conducted June 2020-April 2021, shortly after the introduction of the new supermarket in January 2020. ANCOVA linear regression models were estimated to examine the association between children's proximity to the new supermarket with dietary outcomes at follow-up. Interactions with barriers to food access were also explored. Results: Living close to the new supermarket was not significantly associated with dietary outcomes at follow-up. However, for children who lived in households with no vehicle access, living close to the new supermarket was associated with increased fruit and vegetable consumption, compared to children in the comparison group. Conclusion: Proximity to the new supermarket was not associated with improved dietary outcomes among children unless they had transportation barriers. This adds to the growing body of literature that suggests that the effects of neighborhood food environments may be modified by individuals' mobility, and that comprehensive interventions are needed.