Contrary to the popular belief that potatoes are less healthy plant food and promote weight gain and increase risk for type 2 diabetes, a new study published in the Journal of Medicinal Food has reported that low-energy density diets, consisting of potatoes and beans, are effective in improving insulin resistance and reducing body weight in subjects with insulin resistance.
A randomized, parallel-group trial included 36 adult participants with insulin resistance (homeostatic model assessment of insulin resistance [HOMA-IR] >2). The enrolled participants were administered a potato or bean diet, consisting of 50–55% carbohydrate, 30–35% fat, and 15–20% protein, for 8 weeks. In the potato diet, each meal comprised of 3 ounces of cooked meat or fish and 2 ounces of potatoes (boiled with skin and refrigerated for 12–24 h before use), with a side of potatoes. The bean diet consisted of 3 ounces of cooked meat or fish and 2 ounces of cooked pulse, with a side of bread, rice, or pasta. The subjects underwent weight measurement and a mixed-meal tolerance test, at baseline and after 8 weeks of intervention.
At baseline, fasting glucose concentrations were normal (<100 mg/dL) in both the diet groups. Blood glucose response was comparable in both the diet groups; no significant reduction was noted in the serum glucose concentration. Reduction in insulin resistance, body weight, and body mass index were observed in both the diet groups (see the table below).
Clinical implication: This is a first study to investigate the effect of potato-based diet on metabolic outcomes. Both potato-based and bean-based diets were equally effective in promoting weight loss and improving insulin resistance in adults with insulin resistance. Contrary to the findings of epidemiological studies, potato-based diet did not adversely affect the glycemic response.
(Reference: Rebello CJ, Beyl RA, Greenway FL, et al. Low-energy dense potato- and bean-based diets reduce body weight and insulin resistance: A randomized, feeding, equivalence trial. J Med Food. 2022;25(12):1155-63.)