The effect of increasing consumption of pulses and wholegrains in obese people: A randomized controlled trial

Background: Wholegrain intake is inversely related to weight gain over time, but little information is available on the role of pulses in weight control. Objective: To compare weight loss, metabolic outcomes, and nutrient intakes in obese people assigned to a diet rich in pulses and wholegrains or a control diet. Methods: Randomized controlled study of 18 months with 113 volunteers (body mass index [BMI] ≥ 28 kg/m²). Diets were based on guidelines published by the National Heart Foundation of New Zealand. The intervention group was advised to consume 2 serves of pulses and 4 serves of wholegrain foods per day as substitutions for more refined carbohydrates. Results: Fiber intakes were higher, intakes of several vitamins and minerals were better maintained, and dietary glycemic index was lower in the intervention compared with the control group. Mean (standard error [SE]) weight loss at 6 months was 6.0 (0.7) kg and 6.3 (0.6) kg in the control and intervention groups, respectively, and was not different between groups (p > 0.05). Blood pressure, triglycerides, and glycemic load were lowered in both groups compared with baseline. Waist circumference was decreased at 18 months in the intervention compared with the control group (−2.8 cm; 95% confidence interval [CI]: −0.4, −5.1). Conclusions: Incorporation of pulses and wholegrain foods into a weight loss program resulted in a greater reduction in waist circumference compared with the group consuming a control diet, although no difference in weight loss was noted between groups. Retention of several nutrients was better with the pulse and wholegrain diet.