Dietary patterns and their associations with obesity in the Brazilian city of Rio de Janeiro

OBJECTIVE: To evaluate the dietary patterns of adults living in the city of Rio de Janeiro, Brazil and their associations with body mass index (BMI). RESEARCH METHODS AND PROCEDURES: A survey was conducted in 1996 in a probabilistic sample of 2040 households. Weight and height were measured and food intake was based on an 80-item semi-quantitative food frequency questionnaire. Dietary patterns were identified through factor analysis. RESULTS: More than one-third of the adult population (20 to 60 years old) was overweight (BMI = 25 to 29.9 kg/m(2)), and 12% were obese (BMI >or= 30 kg/m(2)). Three major dietary patterns were identified: mixed pattern when all food groups and items had about the same factor loading, except for rice and beans; one pattern that relies mainly on rice and beans, which was called a traditional diet; and a third pattern, termed a Western diet, where fat (butter and margarine) and added sugar (sodas) showed the highest positive loading and rice and beans were strong negative components. Among men, the Western diet also included deep-fried snacks and milk products with high positive values. The traditional diet was associated with lower risk of overweight/obesity in logistic models adjusted for dieting, age, leisure physical activity, and occupation (13% reduction in men and 14% reduction in women comparing the traditional and Western diets). DISCUSSION: Factors contributing to the effects of the Brazilian traditional diet may include low-energy density, high-dietary fiber content, incorporation of low glycemic index foods such as beans, or a relatively low food variety.