BMJ

Higher intake of French fries—but not boiled potatoes—drives T2DM risk

August 8, 2025

Study details: A large prospective analysis pooled data from three major U.S. cohorts (Nurses’ Health Study, Nurses’ Health Study II, and Health Professionals Follow-up Study; N=205,107; >5 million person-years) to assess the association between total and specific potato intake and incident T2DM. The study also performed substitution analyses and a meta-analysis of 13 cohorts to evaluate the impact on T2DM of replacing potatoes with other carbohydrate sources.

Results: Higher intake of total potatoes and especially French fries was associated with increased T2DM risk. Each additional three servings per week of total potatoes increased T2DM risk by 5% (95% confidence interval [CI], 1.02–1.08), while the same increment of French fries increased risk by 20% (95% CI, 1.12–1.28). Baked, boiled, or mashed potatoes weren’t significantly associated with T2DM risk. Substitution analyses showed that replacing three weekly servings of French fries with whole grains was associated with a 19% lower T2DM risk, while replacing potatoes with white rice increased risk.

Clinical impact: These findings support dietary guidance to limit fried potato intake, particularly French fries, as part of T2DM prevention. Replacing French fries with whole grains may confer substantial risk reduction, while non-fried potatoes appear neutral for T2DM risk when compared with other carbohydrate sources.

Source:

Mousavi SM, et al. (2025, August 6). BMJ. Total and specific potato intake and risk of type 2 diabetes: results from three US cohort studies and a substitution meta-analysis of prospective cohorts. https://pubmed.ncbi.nlm.nih.gov/40769531/