Proximity of supermarkets is positively associated with diet quality index for pregnancy.

Objectives: To investigate the association between distance to the closest supermarket and a composite measure of diet, the diet quality index for pregnancy (DQI-P) was constructed.
Methods: Data from the Pregnancy, Infection and Nutrition (PIN) cohort, a prospective study of determinants of preterm birth, were analyzed. Food frequency questionnaires were used to construct DQI-P which includes: servings of grains, vegetables, fruits, folate, iron and calcium intake, percentage of calories from fat, and meal pattern score. Street address of residence, supermarkets, grocery and convenience stores were geocoded. Participants with complete food frequency and address data were included (n = 918). Multinomial logistic regression was used to estimate the conditional association of food outlets on diet quality, controlling for confounders and using a robust variance estimator to account for clustering of neighborhood characteristics.
Results: Women living greater than 4 miles from a supermarket were more than twice the odds (adjusted odds ratio = 2.16; 95% confidence interval = 1.2, 4.0) of falling into the lowest compared to highest DQI-P tertile compared to women living within 2 miles of a supermarket, after controlling for individual characteristics, other food retail outlets.
Conclusion: These findings suggest that proximity of food retail outlets influences the diet quality of pregnant women.