Improvement in metabolic parameters in obese subjects after 16 weeks on a Brazilian-staple calorie-restricted diet

BACKGROUND/OBJECTIVES: The standard pattern of Brazilian food consumption is based on the combination of rice and beans served together in the main meals. This study assessed the effects of Brazilian-staple calorie-restricted (BS-diet) dietary advice, with brown rice and beans, on metabolic parameters, body composition, and food intake in overweight/obese subjects. SUBJECTS/METHODS: Twentyseven subjects were randomly assigned to a conventional-type calorie-restricted diet (CT-diet) (n = 13) or a BS-diet (n = 14). Glucose metabolism, lipid profile, anthropometric and body composition parameters, and food intake were measured before and after 16 weeks. Paired t-tests/Wilcoxon tests were used for comparison of differences from baseline and unpaired t-tests/Mann-Whitney tests were used for comparison of differences between the groups. RESULTS: After 16 weeks, both groups showed reductions in weight and waist circumference (P < 0.02), and the BS-diet group showed a decrease in body fat (P = 0.0001), and significant improvement in glucose metabolism (fasting plasma glucose, glucose and insulin areas under the curve, Cederholm index, and HOMA2-%β) (P ≤ 0.04) and lipid profile (cholesterol, triacylglycerol, LDL-c, VLDL-c, and cholesterol/HDL-c ratio) (P ≤ 0.05). In addition, the BS-diet group showed significant improvement in HOMA2-%β, compared to the CT-diet group (P = 0.03). The BS-diet group also showed a significant reduction in energy, lipids, carbohydrate, and cholesterol intake (P ≤ 0.04) and an increase in fiber intake (P ≤ 0.001), while the CT-diet group showed a significant reduction in intake of energy, macronutrients, PUFA, and cholesterol (P ≤ 0.002). CONCLUSIONS: These results demonstrate the benefits of the BS-diet on metabolic parameters in obese subjects.