Associations between retail food environment and the nutritional quality of food purchases in French households: The Mont'Panier cross-sectional study

Purpose The purpose of this study was to assess whether the retail food environment, measured by multiple indicators around the home and in activity space, was associated with the nutritional quality of food purchases. Methods This cross-sectional study included 462 households from a quota sampling survey conducted in the south of France (Montpellier Metropolitan Area). The revised Healthy Purchase Index was implemented in order to assess the nutritional quality of food purchases. Food environment indicators (presence, number, relative density and proximity of food outlets) were calculated around the home and in activity space using a geographical information system. Six different types of food outlets were studied: supermarkets, markets, greengrocers, bakeries, other specialized food stores (butcher's, fishmonger's and dairy stores) and small grocery stores. Associations between food environment and the nutritional quality of food purchases were assessed using multilevel models, and geographically weighted regressions to account for spatial non-stationarity. Models were adjusted for households' socioeconomic and demographic characteristics. Results The nutritional quality of food purchases was positively associated with the number of greengrocers around the home (1 vs. 0: beta = 0.25, 95%CI = [0.01, 0.49]; >1 vs. 0: beta = 0.25, 95%CI = [0.00, 0.50]), but negatively associated with the number of markets around the home (1 vs. 0: beta = -0.20, 95%CI = [-0.40, 0.00]; >1 vs. 0: beta = -0.37, 95%CI = [-0.69, -0.06]). These associations varied across space in the area studied. For lower income households, the number of greengrocers in activity space was positively associated with the nutritional quality of food purchases (1 vs. 0: beta = 0.70, 95%CI = [0.12, 1.3]; >1 vs. 0: beta = 0.67, 95%CI = [0.22, 1.1]). Conclusions Greengrocers might be an effective type of food store for promoting healthier dietary behaviors. Further studies, particularly interventional studies, are needed to confirm these results in order to guide public health policies in actions designed to improve the food environment.