Is banana good for diabetics?
Banana is a low-glycemic food: its glycemic index is 52 (median of 2 lab tests, range 47 to 57). A serving of 1 banana, peeled (4.1 oz, 115 g) has 26.4 g of carbs and 2 g of fiber, a glycemic load of about 13.
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 banana, peeled (4.1 oz, 115 g) | Amount |
|---|---|
| Total carbohydrate | 26.4 g |
| Fiber | 2 g |
| Sugars | 18.2 g |
| Carbs minus fiber | 24.5 g |
| Glycemic load (GI × carbs minus fiber ÷ 100) | 13 |
USDA FoodData Central, Bananas, ripe and slightly ripe, raw. Glycemic load uses the median GI below.
Glycemic index tests
| Food as tested | GI | Category | Country |
|---|---|---|---|
| Banana, raw | 47 | low | Australia |
| Banana, raw, overripe | 57 | medium | Australia |
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 |
|---|---|---|---|---|
| Banana | 1 banana, peeled (4.1 oz, 115 g) | 52 | 26.4 g | 13 |
| Watermelon | 1 cup, balls (5.4 oz, 154 g) | 50 | 11.6 g | 6 |
| Apple | 1 cup, quartered or chopped (4.4 oz, 125 g) | 44 | 17.3 g | 6 |
| Grapes | 1 cup (5.3 oz, 151 g) | 54 | 27.3 g | 14 |
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 banana
- Level A A meta-analysis of 22 randomized trials with 670 people found that resistant starch type 2, the kind in green banana, lowered body weight only in type 2 diabetes, by 2.8 lb (1.29 kg) in 90 people, a result driven by a few small studies. Nutrients, 2019
- Level B Eating 8.8 oz (250 g) of banana every morning for 12 weeks did nothing harmful to people with high cholesterol or type 2 diabetes, and did very little good either. Indian Journal of Experimental Biology, 2014
- Level B The banana has the highest glycemic index of eight common fruits tested in people with type 2 diabetes, and the difference between all eight was not statistically significant. Bianchi et al., Diabetic Medicine, 1995
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
Ripeness moves the number. In two Australian lab tests, a raw banana scored 47 and an overripe one 57, so a spotty banana crosses into the medium band (56 to 69).
The size of the fruit matters more than the index. One banana has 26.4 g of carbs, more than twice the 11.6 g in a cup of watermelon. Its glycemic load of 13 is about double that of a cup of apple or watermelon (about 6). If you count carbs for insulin or for gestational diabetes, use the method your care team taught you: 26.4 g total, or 24.5 g without fiber.
The lab tests above were done in healthy adults. In one trial in 61 people with type 2 diabetes, the GI of eight common fruits ran from 60 for pears to 83 for banana, higher than in those tests. The gap between the eight was too small to call a real difference.
Evidence behind this note
- Level B The banana has the highest glycemic index of eight common fruits tested in people with type 2 diabetes, and the difference between all eight was not statistically significant. Bianchi et al., Diabetic Medicine, 1995
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, Foundation Foods (release 2025-12-18): Bananas, ripe and slightly ripe, raw, FDC ID 1105314
- USDA FoodData Central, SR Legacy (2018): Watermelon, raw, FDC ID 167765
- USDA FoodData Central, SR Legacy (2018): Apples, raw, with skin (Includes foods for USDA's Food Distribution Program), FDC ID 171688
- USDA FoodData Central, SR Legacy (2018): Grapes, red or green (European type, such as Thompson seedless), raw, FDC ID 174683
- 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.