Blueberries and Diabetes: Carbs, Glycemic Index and Portions
A cup of blueberries has about 21 g of carbohydrate (18 g net). Glycemic index: no value in the tables we use. Yes. Blueberries are a fiber-containing fruit that fits in most plans, in measured portions.
A cup of blueberries has less carbohydrate than many other fruits in a typical serving and brings fiber with it. They are a good topper for oatmeal and yogurt.
Fresh and unsweetened frozen are the best forms. Dried blueberries and blueberry muffins are a different story, with much more concentrated sugar.
Carbs in blueberries by portion
| Portion | Grams | Carbs (g) | Fiber (g) | Net carbs (g) | Protein (g) |
|---|---|---|---|---|---|
| cup | 148 | 21 | 3.6 | 18 | 1 |
| 50 berries | 68 | 9.9 | 1.6 | 8.2 | 0.5 |
| 100 g (for comparing foods) | 100 | 15 | 2.4 | 12 | 0.7 |
Source: USDA FoodData Central, FDC ID 171711 (Blueberries). Net carbs here means carbohydrate minus fiber. “Net carbs” is not an FDA-defined term, so total carbs are shown too. Values are estimates for a typical item; brands, ripeness and size vary.
Glycemic index and glycemic load
Glycemic index: no value shown. The one blueberry entry is labelled inconsistently in the table, so we do not use it. We do not estimate values that are not published.
Glycemic index is only one piece of the picture. The same food can give a different response depending on ripeness, cooking, what you eat it with and your own body, so your meter or CGM is the best guide.
How blueberries fit the plate method
Blueberries count toward the carbohydrate quarter of the plate in the plate method, along with grains, starchy vegetables, fruit and milk. The CDC describes the plate method as half non-starchy vegetables, a quarter protein and a quarter carbohydrate foods. See the diabetic meal plan guide for how it works, or drop blueberries onto a meal in the meal planner to watch the plate fill.
Portion ideas and pairings
- A half to one cup.
- Freeze a bag and take out a portion at a time.
- Muffins and pie are a much larger carbohydrate load.
Pairs well with: plain Greek-style yogurt, oatmeal, a few nuts.
Related foods
Banana
1 medium: 27 g carbs
Apple
cup, quartered or chopped: 17 g carbs
Strawberries
cup, halves: 12 g carbs
Watermelon
cup, balls: 12 g carbs
See all foods and the low glycemic foods list
Frequently asked questions
Are berries the best fruit for diabetes?
They are often recommended because a serving has relatively little carbohydrate and plenty of fiber, but any whole fruit can fit in a measured portion.
How many carbs are in a cup of blueberries?
About 21 g of carbohydrate, of which about 3.6 g is fiber, so roughly 18 g net carbs. Values are from USDA FoodData Central for 148 g and are estimates; brands and sizes vary.
Information only, not medical advice. Your care team may set different targets for you, and only a lab test ordered by a clinician can diagnose diabetes or prediabetes. See our medical disclaimer.
Sources
- USDA FoodData Central: Blueberries (FDC ID 171711)
- Atkinson FS et al. International tables of glycemic index and glycemic load values 2021. Am J Clin Nutr 2021;114(5):1625-1632
- CDC: Diabetes Meal Planning (plate method and carbohydrate counting)
- ADA Standards of Care in Diabetes—2026, Section 5: Facilitating Positive Health Behaviors
Last reviewed: by the Diabetes Blogs editorial team. Information only, not medical advice.
