A randomized controlled trial to evaluate the effect of incorporating peanuts into an American Diabetes Association meal plan on the nutrient profile of the total diet and cardiometabolic parameters of adults with type 2 diabetes

BACKGROUND According to the American Diabetes Association (ADA), the nutritional goals for patients with type 2 diabetes (T2D) are to achieve an optimal nutrient intake to achieve normoglycemia and a cardioprotective lipid profile. Peanuts are nutrient dense foods that contain high levels of monounsaturated fat (MUFA) and are a natural source of arginine, fiber, phytosterols, resveritrol, niacin, folate, vitamin E and magnesium, which have the potential for improving blood lipids and glycemic control. This study sought to evaluate the effect of a peanut enriched ADA meal plan on the nutrient profile of the total diet and cardiometabolic parameters in adults with T2D. METHODS This was a randomized, prospective 24-week parallel-group clinical trial with 60 adults with T2D [age range 34-84 years; body mass index (BMI) range 17.2-48.7 kg/m2]. Subjects consumed an ADA meal plan containing ~20% of energy from peanuts (peanut group) or a peanut-free ADA meal plan (control group). Weight, BMI, waist circumference (WC) and nutrient intake from 24-hour recalls were measured every 4 weeks and fasting blood glucose (FBG), HbA1c and blood lipids were measured every 12 weeks. A mixed-model repeated-measures analysis of covariance was performed to assess the significance of changes in the cardiometabolic parameters. RESULTS A higher polyunsaturated fat (PUFA) to saturated fat diet ratio and higher intake of MUFA, PUFA, α-tocopherol, niacin and magnesium was observed in the peanut group as compared to the control group (P < 0.01-P = 0.04). Both groups experienced mild reductions in weight, BMI, and WC during the study (P = 0.01-P = 0.03), however there were no differences between the two groups in these measurements or in FBG, HbA1c or blood lipids. For each kilogram of weight loss in the entire cohort there were associations for reductions in WC of 0.48 cm (P < 0.01), FBG of 0.11 mmol/l (P = 0.01) and HbA1c of 0.07% (P < 0.01). CONCLUSIONS Daily consumption of a peanut enriched (46 g/d) ADA meal plan over 24 weeks improves the nutrient profile of the total diet and is compatible with weight management and improvement in specific blood lipids. TRIAL REGISTRATION ClinicalTrials.gov NCT00937222.