ABSTRACT
Introduction
Understanding what influences where food outlets locate is important for bemitigating disparities in access to healthy food outlets. However, few studies have examined how neighborhood characteristics influence the neighborhood food environment over time, and whether these relationships differ by neighborhood-level income.
Methods
Neighborhood-level data from four U.S. cities (Birmingham, AL; Chicago, IL; Minneapolis, MN; Oakland, CA) from 1986, 1993, 1996, 2001, 2006, and 2011 were used with two-step econometric models to estimate longitudinal associations between neighborhood-level characteristics (z -scores) and the log-transformed count/km2 (density) of food outlets within real-estate-derived neighborhoods. We examined associations with lagged neighborhood-level sociodemographics and lagged density of food outlets, with interaction terms for neighborhood-level income. Data were analyzed in 2016.
Results
Neighborhood-level income at earlier years was negatively associated with the current density of convenience stores (β= −0.27; 95% CI: −0.16, −0.38; p<0.001). The percentage of neighborhood white population was negatively associated with fast food restaurant density in low income neighborhoods (10th percentile of income: β= −0.17; 95% CI: −0.34, −0.002; p=0.05), and the density of smaller grocery stores across all income levels (β= −0.27; 95% CI: −0.45, −0.09; p=0.003). There was a lack of policy-relevant associations between the pre-existing food environment and the current density of food outlet types, including supermarkets.
Conclusions
Socioeconomically-disadvantaged populations and minority populations may attract ‘unhealthy’ food outlets over time. To support equal access to healthy food outlets, the availability of ‘less healthy’ food outlets types may be relatively more important than the potential lack of supermarkets or full-service restaurants.