Carbs in banana
Per 1 medium (118 g)
27g
Total carbs
3g
Fiber
24g
Net carbs
14g
Sugars
Values are typical for the stated serving, consistent with USDA FoodData Central; brands and preparations vary. GI reference: glucose = 100.
What banana actually does
A banana is basically a ripeness dial for blood sugar: green-tinged bananas are full of resistant starch that digests slowly, while brown-spotted ones have converted most of it to sugar and hit much faster — the GI climbs from around 42 to over 60 as it ripens. A medium banana carries about 27 g of carbs, more than most people guess for a piece of fruit. Blending changes it too: a banana in a smoothie hits faster than a banana eaten whole, because the fiber structure is destroyed and there is nothing to chew. Many T1s keep bananas around specifically as a portable low treatment for exactly this reason — they work fast when ripe.
Moderate rise around 45–60 minutes — noticeably faster the riper it is.
Worth trying
Pick firmer, less-ripe bananas for snacking and pair with peanut butter or nuts — the fat and protein flatten the curve noticeably. Save the spotty ones for treating lows.
Common questions
Can diabetics eat bananas?
Yes — a banana is about 27 g of carbs with real fiber, comparable to two slices of bread. Ripeness is the variable that matters most: greener bananas digest slowly, very ripe ones behave closer to candy. Plenty of people with T1 eat them daily; it is about knowing the count and your own response.
Are bananas high glycemic?
A typical yellow banana is actually low-GI, around 51. But that number slides with ripeness — under-ripe bananas test near 42 while very ripe ones exceed 60. The carb total stays about the same; only the speed changes.
Related foods
Real quick — we’re not your doctor. Everything on this page is general information, not medical advice, and diabetes is deeply individual. CarbLens AI never recommends insulin doses. Use what you learn here to have smarter conversations with your care team.
See what banana does to YOUR blood sugar.
Averages are averages. CarbLens AI logs your meal and shows the 3-hour curve your own body produced.
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