Local food environment associated with diet and obesity among California adults

Increasingly, research is associating the retail food environment with dietary behaviors and health outcomes. Using data from the 2005 California Health Interview Survey (CHIS), a random-digit dial (RDD) telephone survey of California households, an InfoUSA business database and the US Census, we examined the association of the food environment with obesity and fruit and vegetable consumption among adults. The food environment was characterized in terms of the availability of fast food restaurants and convenience stores relative to grocery stores and produce markets. Specifically, we used a ratio of fast food outlets and convenience stores to grocery stores and produce markets within buffers around individual CHIS respondents' home addresses – called the retail food environment index (RFEI). A higher RFEI represents greater availability of fast food and convenience stores relative to grocery stores and produce markets, arguably a worse food environment. Adults with lower RFEIs (<3) had a lower prevalence of obesity (20%) than adults with RFEIs between 3 and 5 (23%) or of 5+ (24%; p<0.05). Likewise, the percentage eating at least five servings of fruits and vegetables per day (42%) was higher among those with a lower RFEI (<3) than among adults with RFEIs between 3 and 5 (38%) or of 5+ (37%; p<0.001). Regression analyses showed that these associations remain significant after adjusting for individual income, race/ethnicity, age and neighborhood poverty. The food environment also varies with individual and neighborhood sociodemographic factors. Improving the retail food environment could help improve dietary behaviors and weight status of California adults.