Food deserts and swamps in a Southern Brazilian conurbation: socio-spatial determinants of the urban food environment

Abstract This study examines the spatial distribution of healthy and unhealthy food outlets and assesses how commonly used metrics of food deserts and food swamps relate to socio-spatial characteristics in a medium-sized Brazilian conurbation. Spatial accessibility was measured using population-based indicators of outlet density within walkable distances, and associations with socioeconomic and urban structure variables were analyzed using spatial autocorrelation and regression models. Food outlets were strongly concentrated in central, consolidated urban areas, with both healthy and unhealthy establishments following similar spatial patterns. Areas classified as food deserts were mostly located in peripheral zones with lower overall commercial density, while food swamps were more widely distributed. Access to healthy food outlets was positively associated with income and urban consolidation, and negatively associated with peripheralization and distance to arterial roads. However, classifications of food deserts and food swamps proved highly sensitive to methodological choices and closely aligned with broader patterns of urban structure. In a context of generally high spatial accessibility, these metrics appear to capture relative differences in commercial density rather than absolute constraints on food access. These findings suggest that density-based spatial indicators should be interpreted with caution, as they may more reflect underlying socio-spatial organization, rather than meaningful inequalities in access to food.