Epidemiology of overweight and obesity and its determinants in Belo Horizonte (MG), Brazil:: a cross-sectional population-based study

Objective. To determine the prevalence of overweight and obesity and to study potential risk factors for these conditions in persons over 18 years of age in the metropolitan area of Belo Horizonte, Brazil. Methods. Data were obtained from a population-based study conducted in 1996 and 1997 by the Brazilian Institute of Geography and Statistics (Instituto Brasileiro de Geografia e Estatistica, IBGE) with a random sample of 1 105 individuals. Height and weight were measured by trained personnel. Overweight (body mass index [BMI] greater than or equal to 25.0 kg/m(2)) and obesity (BMI greater than or equal to 30.0 kg/m(2)) were the dependent variables. Bivariate analysis and multivariate logistic regression were used to identify potential risk factors for overweight and obesity. Results. The prevalence of overweight and obesity was 31.1% (95% confidence interval [95% CI]: 27.3 to 35.2) and 5.7% (95% CI: 4.0 to 8.1), respectively, in men, and 25.9% (95% CI: 22.4 to 29.8) and 14.7% (95% CI: 11.9 to 17.9), respectively, in women. Multivariate analysis revealed that age and marital status were independent risk factors for overweight, whereas age, sex, and education were independent risk factors for obesity. Being female and well-educated showed a protective effect against overweight (odds ratio [OR] = 0.52; 95% CI: 0.33 to 0.83), but not against obesity (OR = 3.01; IC 95%: 1.14 to 7.94). Women with low education had a significantly greater risk (OR = 5.95; 95%CI: 2.51 to 14.12) of developing obesity than men having a high educational level. Conclusions. These results suggest that overweight and obesity may be serious public health problems in the metropolitan area of Belo Horizonte, Brazil. It is important to carry out further studies in order to explore the potential relationship between overweight and obesity on the one hand, and behavioral variables, such as smoking and alcohol consumption, on the other.