[Gender and age differences in social support and body mass index in adults in Greater Metropolitan Rio de Janeiro, Brazil].

The objective was to investigate gender and age differences in the association between dimensions of social support and body mass index (BMI) in a sample of 1,465 adults (20 to 59 years) in a population-based study in Duque de Caxias, Rio de Janeiro State, Brazil. Anthropometry was conducted by trained evaluators and social support obtained by the Medical Outcomes Study, adapted and validated for the Brazilian population. The analyses were performed with multiple linear regressions, stratified by gender and age bracket, considering the sample's expansion factor and complex design. Obesity prevalence was 28% in women and 16.2% in men. After adjusting for confounders, a negative association was observed between social support and BMI in men 40-49 years of age, and in emotional support/information (β = -2.04), and positive social interaction (β = -2.40). There was a positive association for social support and BMI in men 50-59 years of age in emotional support/information (β = 1.84). The study indicates that social support can protect against obesity in men in some dimensions and age brackets. However, social support does not appear to be a protective factor in women.