Background: Existing research has established a link between dietary intake and adiposity measures, including body mass index (BMI) and waist circumference (WC). However, less is known about the relationship between objective food environment quality measures and adiposity [BMI and WC], particularly in diverse populations.
Methods: Using cross-sectional data from the 2007-2009 Dallas Heart Study multi-ethnic cohort, we examined the relationship between local food environment quality and adiposity. We measured individuals’ census tract-level food environment quality using the CDC’s Modified Retail Food Environment Index (mRFEI), a ratio of healthy to unhealthy food stores within a ½ mile radius of each census tract (higher mRFEI=more healthy food access). We characterized BMI and WC as continuous measures. Using linear regression, we investigated the relationship between mRFEI and BMI/WC adjusting for confounders [age, gender, race/ethnicity, income, education, smoking status, and neighborhood deprivation index (NDI)]. Models were stratified by NDI to identify if these relationships were moderated by neighborhood deprivation.
Results: The study population (n=1835) was 58% non-Hispanic blacks, 27% non-Hispanic whites, and 15% Hispanics. The mRFEI ranged from 0 to 50 across census tracts. In the fully adjusted model, higher mRFEI was associated with higher BMI (β=0.06 p=0.01), but not WC (β=0.09 p=0.13). When stratified by NDI, higher mRFEI was associated with greater BMI and WC in low deprivation areas, but not in medium or high deprivation areas (Figure).
Conclusions: Better neighborhood food environment quality was paradoxically associated with higher adiposity in low NDI areas among a diverse population in Dallas County, Texas. Our findings contribute to growing literature around aggregate measures of food environment quality, highlighting potential limitations of the mRFEI in characterizing the impact of the spatial distribution of healthy food outlets on adiposity in lower resource environments.