Spatiotemporal trends in food deserts, food swamps and food environments around schools in Wallonia, Belgium (2008–2024)

BACKGROUND: Food environments influence dietary behaviors and nutritional health outcomes. Food deserts, areas characterized by limited spatial access to healthy foods, and food swamps, areas where unhealthy outlets predominate, present challenges to the adoption and maintenance of a healthy diet. This study analyzed trends in access to healthy and unhealthy food environments in neighborhoods and around schools in Wallonia, Belgium, over the period 2008-2024. The region remains understudied and offers a particularly insightful case due to its mix of urban and rural areas. METHODS: We combined data on geocoded food outlets (Locatus database), short chain initiatives (LogCiCa), schools, road networks, residential addresses and area socio-demographic characteristics to identify and quantify food deserts, food swamps and the food environment within 1000m around schools across the study region. Potential food deserts were defined as areas lacking a supermarket within 1000 m road distance and a bus stop within 500 m, while actual food deserts additionally required high proportions of low-income households or elderly (65 years and older). Food swamps were quantified using the modified Retail Food Environment Index (mRFEI). Food environments around 4,696 schools were assessed using 1000 m road-network buffers. Temporal trends were evaluated using linear regression. RESULTS: Between 2008 and 2024, approximately 11% of households lived in potential food deserts, with fewer than 2% residing in actual food deserts. In contrast, food swamps were widespread: in 2024, 52.2% of households were located in sectors where unhealthy outlets outnumbered healthy ones. Sectors with high proportions of elderly residents or children were disproportionately affected. Around secondary schools, traditional fresh food retailers declined substantially (fruit and vegetable stores - 60%), while takeaway and delivery outlets increased threefold. By 2024, over 90% of secondary schools were located in predominantly unhealthy food environments within walking distance. CONCLUSIONS: In Wallonia, exposure to unhealthy food environments is widespread and persistent, particularly around schools and in socio-demographically vulnerable areas, while food deserts remain relatively rare. Policy efforts addressing the density and spatial distribution of unhealthy outlets may contribute to reducing dietary inequalities and improving population health.