This cross-sectional study of 570 adults aimed to identify factors associated with overweight and abdominal fat in adults of both sexes in the city of Salvador, Bahia State, Brazil. Body mass index (BMI) and waist circumference were the dependent variables, and Poisson regression was used for statistical analysis. For women, high BMI and waist circumference were associated with increased age and current dieting (< or = 3 meals a day), while family history of obesity was only associated with increased BMI. In men, BMI increased in the 30-39 and 50-59-year age brackets. Waist circumference increased in association with < or = 3 meals a day, arterial hypertension, and alcohol consumption, and was lower among blacks and mixed-race individuals. High BMI and waist circumference were both associated with family history of myocardial infarction. Thus, factors associated with overweight and abdominal fat differ between men and women, but adopting healthier lifestyles can help modify many of these factors.