Is potato good for diabetics?
Boiled potato is a medium-glycemic food: its glycemic index is 66 (median of 7 lab tests, range 38 to 82). A serving of 1/2 cup (2.8 oz, 78 g) has 15.7 g of carbs and 1.4 g of fiber, a glycemic load of about 9.
This page is for people with diabetes or prediabetes. The glycemic index compares foods, and the glycemic load on this page adjusts it for a real serving. If you follow a meal plan from your care team, use these numbers within it.
Carbs in a serving
| Per 1/2 cup (2.8 oz, 78 g) | Amount |
|---|---|
| Total carbohydrate | 15.7 g |
| Fiber | 1.4 g |
| Sugars | 0.7 g |
| Carbs minus fiber | 14.3 g |
| Glycemic load (GI × carbs minus fiber ÷ 100) | 9 |
USDA FoodData Central, Potatoes, boiled, cooked in skin, flesh, without salt. Glycemic load uses the median GI below.
Glycemic index tests
| Food as tested | GI | Category | Country |
|---|---|---|---|
| Potato, novel clone, selection 2 (CV1102-1, grown in Alberta; harvested prior to maturity Oct. 2009),... | 38 | low | Canada |
| Potato, red, cubed, boiled in salted water 12 min, stored overnight in refrigerator, consumed cold | 56 | medium | Canada |
| Potato, novel clone, selection 1 (CV92056-4, grown to maturity in Alberta, harvested Oct. 2008), unpeeled,... | 60 | medium | Canada |
| Potato, NS, boiled | 66 | medium | China |
| Potato, novel clone, selection 4 (F03028, grown in New Brunswick), unpeeled, cut into 2.5-3 cm cubes,... | 72 | high | Canada |
| Potato, novel clone, selection 3 (F03031, grown in New Brunswick), unpeeled, cut into 2.5-3 cm cubes,... | 79 | high | Canada |
| Potato, novel clone, selection 1 (CV92056-4, grown in Ontario; harvested Oct. 2009), unpeeled, cut into... | 82 | high | Canada |
Glucose = 100. Categories from the International Tables: low 55 or less, medium 56 to 69, high 70 or more. Only tests that met the ISO 26642:2010 method (Supplemental Table 1).
Compared with similar foods
| Food | Portion | GI | Carbs | Glycemic load |
|---|---|---|---|---|
| Potato | 1/2 cup (2.8 oz, 78 g) | 66 | 15.7 g | 9 |
| Carrot | 1/2 cup slices (2.8 oz, 78 g) | 32 | 6.4 g | 1 |
| Pumpkin | 1 cup, mashed (8.6 oz, 245 g) | 66 | 12 g | 6 |
| Sweet potato | 1 cup (7.1 oz, 200 g) | 87 | 41.4 g | 30 |
Same food group in the International Tables, each at its usual US portion (USDA).
How much the glycemic index matters
Studies and guidelines do not agree on how much weight to give the glycemic index.
- Level C A year after the World Health Organization set the glycemic index aside, a meta-analysis of cohorts each over a hundred thousand people linked high glycemic index diets to more diabetes, heart disease and death. Lancet Diabetes & Endocrinology, 2024
- Level E The World Health Organization examined the glycemic index, found it inconsistent, and refused to build guidance on it. Carbohydrate intake for adults and children: WHO guideline, 2023
- Level C Glycemic index and glycemic load, the other two ways of judging carbohydrate, held up far worse than fiber in the same analysis. Reynolds et al., The Lancet, 2019
What studies found about potato
- Level B Potato baked then chilled cut the insulin response by a quarter compared with the same potato boiled and served hot. Nutrients, 2019
- Level B Firm-cooked potato swapped for a third of the rice in a meal flattened both the glucose and the insulin peak. Nutrients, 2026
- Level B The one systematic review that went looking found no convincing link between eating potatoes and obesity, diabetes or heart disease. Every study that separated out French fries found a worse picture for the fries. Borch et al., American Journal of Clinical Nutrition, 2016
Levels: A is a meta-analysis of trials, B a randomized trial, C an observational study, D lab or animal work, E an expert position. How we grade evidence.
In practice
The six hot boiled potatoes tested to the ISO standard in healthy adults ranged from 38 to 82, depending on the variety and how mature the potato was. The seventh test in the table, at 56, was a red potato boiled, chilled overnight and eaten cold. Without it the median is 69, still medium, and the half cup load is about 10.
Half a cup of boiled potato has 15.7 g of carbs and a glycemic load of about 9. In one trial in 30 women with a mean BMI of 32.8, a baked potato eaten chilled cut the insulin response at 15 and 30 minutes by about a quarter compared with a hot boiled one. Blood glucose at those points was only 5 to 9% lower.
A firm-cooked potato in place of a third of the rice in a meal flattened the glucose peak in one trial. A full cup is twice the half cup on this page, a load of about 19.
Evidence behind this note
- Level B Potato baked then chilled cut the insulin response by a quarter compared with the same potato boiled and served hot. Nutrients, 2019
- Level B Firm-cooked potato swapped for a third of the rice in a meal flattened both the glucose and the insulin peak. Nutrients, 2026
Written from the agency positions and data on this page, reviewed by the Bioma editorial system. How we verify.
Keep exploring
Sources
- Atkinson FS et al. International tables of glycemic index and glycemic load values 2021: a systematic review. Am J Clin Nutr 2021;114(5):1625-1632, Supplemental Table 1, PMID 34258626, doi:10.1093/ajcn/nqab233 (accessed 2026-10-12)
- USDA FoodData Central, SR Legacy (2018): Potatoes, boiled, cooked in skin, flesh, without salt, FDC ID 170438
- USDA FoodData Central, SR Legacy (2018): Carrots, cooked, boiled, drained, without salt, FDC ID 170394
- USDA FoodData Central, SR Legacy (2018): Pumpkin, cooked, boiled, drained, without salt, FDC ID 168449
- USDA FoodData Central, SR Legacy (2018): Sweet potato, cooked, baked in skin, flesh, without salt, FDC ID 168483
- Evidence cards: each study above links to its source. Card review dates are listed in our methodology.
Sources checked 2026-10-12. Bioma Learn provides information, not medical advice.