Urban violence as a predictor factor of obesity: longitudinal evidence from Sao Paulo, Brazil

Violence and obesity are global public health challenges that impose significant health burdens. However, the prospective association between urban violence and obesity remains insufficiently understood, especially in low- and middle-income countries. This study aimed to investigate if neighborhood crime-related violence is a possible predictor of obesity among adults residing in São Paulo, Brazil.

Data were from the ISA-Physical Activity and Environment cohort study. The sample comprised 815 adults without obesity at baseline, assessed in 2015 and 2021. Violent crime rates within 1,000-meter linear buffers were objectively measured and categorized into five pattens (persistent low violence, decrease, persistent intermediate violence, increase, persistent high violence). Log-binomial and linear regression models were used to evaluate the prospective associations of baseline rates and changes in urban violence with changes in BMI and incidence of obesity from 2015 to 2021.

Over six years, the incidence of obesity was 14.8% (95%CI: 11.88-16.68), along with an average BMI increase of 1.08 kg/m² (95%CI: 0.87-1.28) among adults. Crime rates were associated with residential location, reflecting variations in urban violence across neighborhoods with different socioeconomic contexts. In the fully adjusted model, persistent intermediate violence (IR 2.74, 95%CI: 1.41-5.34), increase (IR 2.48, 95%CI: 1.23-4.98), and persistent high violence (IR 2.77, 95%CI: 1.45-5.26) in violence exposure were positively associated with obesity incidence. But for changes in BMI the relationship was close to statistical significance and was strongest in the persistent high violence group.

Our findings suggest that urban violence may play an important role in the causal pathway of obesity, and the importance of integrating social environmental factors into strategies for obesity prevention.