Background
A growing body of cross-sectional, small-sample research has led to policy strategies to reduce food deserts – neighborhoods with little or no access to healthy foods – by limiting fast food restaurants and small food stores and increasing access to supermarkets in low-income neighborhoods.
Methods
We used 15 years of longitudinal data from the Coronary Artery Risk Development in Young Adults (CARDIA) study, a cohort of U.S. young adults (n=5,115, 18–30 years at baseline), with linked time-varying geographic information system-derived food resource measures. Using repeated measures from four examination periods (n=15,854 person-exam observations) and conditional regression (conditioned on the individual), we modeled fast food consumption, diet quality, and meeting fruit and vegetable recommendations as a function of fast food chain, supermarket, or grocery store availability (counts per population) within 1 kilometer (km), 1–2.9km, 3–4.9km, and 5–8km of respondents’ homes. Models were sex-stratified, controlled for individual sociodemographics and neighborhood poverty, and tested for interaction by individual-level income.
Results
Fast food consumption was related to fast food availability in low-income respondents, particularly within 1–2.9km of homes among men [coefficient (95% CI) up to: 0.34 (0.16, 0.51)]. Greater supermarket availability was generally unrelated to diet quality and fruit and vegetable intake and relationships between grocery store availability and diet outcomes were mixed.
Conclusions
Our findings provide some evidence for zoning restrictions on fast food restaurants within 3km of low-income residents, but suggest that increased access to food stores may require complementary or alternative strategies to promote dietary behavior change.