Factors associated with overweight and central body fat in the city of Rio de Janeiro: results of a two-stage random sampling survey

The purpose of the survey was to investigate the association of overweight (body mass index, BMI) and central body fat distribution (waist/hip girth ratio WHR) with socio-economic, demographic, lifestyle and dietary variables in the adult population of Rio de Janeiro City, Brazil, 1995-1996. A two-stage random sample population-based survey was performed, with 1455 males and 1906 females above 20 y old resident in Rio de Janeiro City, Brazil. Data were obtained by direct interview and physical examination of the subjects. The intake of selected nutrients (fat, saturated fat, cholesterol) and energy was obtained from a semi-quantitative food frequency questionnaire (FFQ). Variables with at least a marginal univariate association with the dependent variables (BMI and WHR) were selected as predictors in two logistic regression models, and variables statistically significant (P<0.05) were retained in them. Overweight prevalence was 44.9%, and 39.2% of the subjects had excessive central body fat distribution (elevated WHR). The proportions of subjects with an excessive intake of fat, saturated fat and cholesterol were respectively 31%, 42% and 47%. For the BMI model, the variables retained were age (OR=1.5, 95% CI=1.3-1.7), schooling (OR=1.7, 1.4-1.9) and smoking (OR=0.8; 0.7-0.9); and for WHR, age (OR=1.8, 1.5-2.1), schooling (OR=2.2, 1.9-2.6), occupation (OR=1.8, 1.1-2.0) and gender (OR=3.9, 3.2-4.7). Obesity and excessive central body fat are highly prevalent health problems in the studied population. As suggested by the identified risk factors, they should be urgently addressed through health nutrition education and physical activity programs; particularly those directed to the middle aged and female groups.