Introduction Marital status has been associated with lower quality of life and chronic conditions.

Objective To evaluate the independent association of marital status with overweight and obesity in a population-based sample from southern Brazil.

Methods A cross-sectional study was conducted in a population-based sampling of 1858 adults aged 18–90 years. Participants were interviewed at home, weight and height were measured to calculate body mass index (BMI). Obesity was define as BMI ≥30 kg/m²; overweight as BMI=25–29 kg/m², and marital status as married, divorced or widow, and single. Prevalence rates (95% CI) and RRs (95% CI) were calculated and multivariate analysis in the Cox Regression Model, using the Complex Samples module of SPSS, to adjust for age, education, gender, and sampling design effect.

Results The sample included 58% of women, aged 48.9 (±19.1) years, and with on average of 9.4 (±4.7) years of formal education. Prevalence of obesity was higher among women (23.5%) than men (17.5%) (p=0.006), but not overweight prevalence (30.4% vs 35.5%, respectively, p=0.2). There was of obesity and overweight with age. In multivariate analysis, obesity remained independently associated with female gender (p=0.03), <12 years at school (p=0.02), age >29 years-old (p<0.001), and being marriaged [(RR=14.4 (1.1–1.8); p=0.02], in comparison to be single. Overweight was also independently associated with age (p<0.001), education (p=0.02) and marital status (p<0.001) for being marriaged [(RR=1.7 (1.3–2.3)], but being separated or divorced reached a borderline significance [RR=1.3 (1.0–1.7)].

Conclusion Married men and women have higher overweight and obesity prevalence independently of socioeconomic characteristics.