The socioeconomic patterning of Great Britain's fast-food outlets and supermarkets: A repeated cross-sectional study of area-level deprivation and food outlet density from 2011 to 2024

Although previous research has demonstrated socioeconomic differences in the distribution of food outlets, no study to date has examined these patterns across the entire territory of Great Britain (GB) over time. This study provides an up-to-date repeated cross-sectional analysis into distributional changes in GB's fast-food outlets and supermarkets from 2011 to 2024 and its socioeconomic distribution. In this study, coordinates of all fast-food outlets and supermarkets in GB from the Ordnance Survey Points-of-Interest data were used to calculate outlet densities within small areas, adjusted by yearly population estimates and linked to Index of Multiple Deprivation measures. Counts of the different food outlets were combined in the modified Retail Food Environment Index (mRFEI). Multi-level linear regression and beta-regression models were used to assess associations between deprivation and fast-food outlet density, supermarket density and mRFEI). Results show that in GB, fast-food outlet density increased by 36 %, supermarket density increased by 17 % and mRFEI decreased by 5 % from 2011 to 2024. More deprived areas were associated with greater fast-food outlet density and lower mRFEI in all years compared to less deprived areas; the gap in fast-food outlet density between the most and least deprived areas widened by 28 % from 2011 to 2024. There were no statistically significant trends in supermarket density by area-level deprivation. Our findings indicate that higher densities of fast-food outlets in more deprived areas are not compensated for by a similar higher density of supermarkets. This imbalance may be limiting healthier dietary choices for residents in these areas. Given the links between food outlet exposure and dietary behaviours in GB, policies aiming to improve dietary outcomes should prioritise more deprived areas, thereby contributing to the reduction of socioeconomic inequalities in the retail food environment, diet, and health outcomes.