The Effects of White Potatoes vs White Rice on Type 2 Diabetes

Swapping white rice for white potatoes daily does not harm blood sugar or cardiovascular markers in adults with type 2 diabetes (T2D) and may even modestly improve body composition and vascular function, according to one study.

This randomized crossover study is published in Current Developments in Nutrition.

Daily potato consumption may improve body composition and vascular health without worsening blood sugar in adults with type 2 diabetes. | Image credit: EMB DESIGNER - stock.adobe.com

“To our knowledge, the extent to which daily whole white potato (including the skin) consumption compared to a commonly consumed staple grain (white rice) affects glycemic control and cardiovascular health in individuals with T2D is unknown,” wrote the researchers of the study. “Therefore, the objective of this study was to determine the effects of white potato consumption compared to white rice (a commonly consumed refined grain) on indices of glycemic control and cardiovascular health in individuals with overweight or obesity and T2D.”

A diabetes diet focuses on eating nutritious foods in moderate amounts and maintaining regular mealtimes.² It emphasizes fruits, vegetables, whole grains, lean proteins, and healthy fats while being naturally low in calories and unhealthy fats. Following a structured eating plan can help people with T2D manage blood sugar, control weight, and reduce the risk of heart disease, high blood pressure, and high cholesterol.

In this trial, 24 adults with T2D, aged 45 to 80 years and with a body mass index of 25 to 40 kg/m², consumed either baked white potatoes (100 g) or calorie-matched white rice (75 g) daily for 12 weeks.¹ The 2 intervention periods were separated by a 2-week washout. Participants underwent assessments at baseline, 6 weeks, and 12 weeks, including measures of glycemic control, blood lipids, inflammation, blood pressure, endothelial function, and body composition. The researchers then evaluated the effects of treatment, time, and the treatment-by-time interaction for all outcomes, with baseline values included as covariates in the analyses.

The study found that daily consumption of white potatoes did not negatively affect glycemic control, blood pressure, lipids, or vascular health compared with white rice. Participants on the potato regimen had lower waist circumference (4.5 ± 1.0 cm reduction, P < .0001), lower body fat percentage (1.7 ± 0.7%, P = .01), reduced waist-to-hip ratio (0.025 ± 0.013, P = .002), higher fat-free mass (1.4 ± 0.7%, P = .05), and a lower resting heart rate (3.1 ± 1.2 bpm, P = .01) than those on the rice regimen.

Vascular function also improved modestly with potatoes, as measured by maximum brachial artery dilation (0.074 ± 0.037 mm, P = .05). Across both groups over time, independent of treatment, β-cell function increased (HOMA-β 34.3 ± 14.5, P = .02), high-sensitivity C-reactive protein decreased (0.08 ± 0.05 μg/mL, P = 0.02), and flow-mediated dilation/shear stress decreased (4.3 × 10⁻⁵ ± 3.79 × 10⁻⁵, P = .03).

However, the researchers acknowledged several limitations. First, this study was limited by a small sample size and the free-living design, which may have allowed unintentional changes in diet, activity, or supplement use. Medication variability and mostly normal baseline blood pressure and lipid levels could have masked potential effects. These factors, along with the preliminary nature of the findings, highlight the need for larger, more controlled trials to confirm the results, noted the researchers.

Despite these limitations, the researchers believe the findings suggest that baked white potatoes with the skin can be a healthy substitute for high-glycemic-load foods like long-grain white rice in individuals with T2D.

“This is the first study to examine the effects of potato consumption on endothelial function, specifically using FMD [flow-mediated dilation], within any population,” wrote the researchers. “There was a significant timepoint effect for FMD/shear stress decreasing in both groups from 6 weeks to 12 weeks (12% for the potato and 23% for the rice regimen, respectively), indicating both groups had a similar degree of impairment in endothelial function during the study.”

References

1. Akhavan NS, Clarke HE, Behl TA, et al. The comparative effects of white potato and white rice consumption on measures of cardiometabolic health in individuals with type 2 diabetes mellitus and features of metabolic syndrome. Curr Dev Nutr. 2025;9(9):107518. doi:10.1016/j.cdnut.2025.107518

2. Diabetes diet: Create your healthy-eating plan. Mayo Clinic. June 11, 2024. Accessed September 10, 2025. https://www.mayoclinic.org/diseases-conditions/diabetes/in-depth/diabetes-diet/art-20044295