Regular users of supermarkets in Greater Tunis have a slightly improved diet quality

Despite the recent and rapid expansion of supermarkets in developing countries, their association with diet quality has been hardly studied. The study took place in Tunisia, where incidences of obesity and nutrition-related diseases are rising. The target population was households of the Greater Tunis area where supermarkets are mostly located. Households (n = 724) were selected by a 2-stage clustered random sampling. A purposely developed quantitative questionnaire assessed food retail habits. Socioeconomic data were collected at individual and household levels. The diet quality index-international (DQI-I) derived from a FFQ specific for Tunisia measured diet quality. Data analysis by regression or logistic regression models adjusted for energy intake and socioeconomic confounders when relevant. Overall, 60% of the households used supermarkets. Most households still used the nearby grocer; only 26% shopped at the market. Characteristics associated with supermarket use were urban milieu, small-sized households, greater educational attainment, higher economic level, steady income, or easy access. Associations between these variables and using supermarkets as a first shopping place (20% of households) were even stronger. After adjustment for energy intake and socioeconomic and access data, using supermarkets chosen as first food shopping place vs. other retail resulted in a slightly higher DQI-I (63.2 vs. 59.6; P = 0.0004). Despite the long-standing presence of supermarkets in Tunis, shopping at supermarkets has not yet spread to the whole population. Supermarkets do not yet markedly modify food consumption in the Greater Tunis. However, a slight improvement of diet quality can be observed among those people who use supermarkets regularly.