[Prevalence and risk factors of obesity in adults].

INTRODUCTION A population-based cross-sectional study was conducted in Pelotas, Southern Brazil, with the objective of determining the prevalence of obesity and identify associated, variables as this condition increased markedly in the country between 1974 and 1989. MATERIAL AND METHODS One thousand and thirty-five adults between 20 and 69 years of age were studied. Obesity was defined as a Body Mass Index--BMI--equal to or over 30 Kg/square meter). The multivariate analyses took into account the hierarchical model of the variables associated with obesity for both men and women. RESULTS The prevalence for the overall population was of 21% (CI 18-23). It was higher among women--25% (CI 22-29) than for men--15% (CI 12-18). Socioeconomic status was positively associated with obesity among men, whereas the opposite situation was reported for women, with those belonging to the poorest social strata presenting increased BMI. Reported obesity in their parents was associated with increased BMI in the subjects, and this association remained statistically significant even after compensating for the effect of possible confounding variables. Self-reported diabetes and arterial hypertension doubled the risk of obesity, whereas non-smoking was associated with obesity only among women. Variables which were not associated with obesity after adjusting for confounders were alcohol consumption, marital status and parity. Women having more daily meals were less prone to obesity, even after controlling for confounders, and this association was not quite significant for men (p = 0.07). CONCLUSIONS The prevalence of obesity was higher among women, and important differences in risk factors were noticed when the population was considered by sex.