A 100-gram serving of plantain (roughly half a cup sliced) contains about 32 grams of carbohydrates. That’s notably more than a banana, which has about 23 grams per 100 grams. But the real story with plantain carbs isn’t just the total number. It’s how dramatically that carb composition shifts depending on whether your plantain is green, yellow, or black.
Carbs by Ripeness Stage
Plantains change more during ripening than almost any other fruit. A green plantain is mostly starch, firm and starchy like a potato. As it ripens to yellow and eventually black, enzymes break that starch down into simple sugars. The total carbohydrate count stays roughly the same, but what those carbs are made of changes completely.
Here’s how the sugar and fiber shift across ripeness levels (per 100g serving):
- Green (underripe): 2.4 grams of sugar, 2.5 grams of fiber
- Yellow (ripe): 14.2 grams of sugar, 2.1 grams of fiber
- Black (overripe): 19.2 grams of sugar, 1.8 grams of fiber
That’s nearly an eightfold increase in sugar from green to black. If you’re watching your sugar intake or managing blood sugar, the color of your plantain matters far more than whether you eat one at all.
How Plantains Compare to Bananas
Plantains and bananas look similar, but their carb profiles are meaningfully different. Per 100 grams, plantains pack about 32 grams of carbs compared to 23 grams in bananas. That’s roughly 40% more. The other key difference: a larger share of the carbs in plantains comes from starch, while bananas lean more toward sugar. This is why plantains are cooked like a vegetable in most cuisines rather than eaten raw as a snack.
Resistant Starch in Green Plantains
Green plantains are unusually high in resistant starch, a type of starch your small intestine can’t break down. Instead, it passes to the large intestine where gut bacteria ferment it, functioning more like fiber than a typical carbohydrate. Raw ripe plantain contains about 20.8 grams of resistant starch per portion (measured against 25 grams of available carbohydrate), though cooking reduces this significantly. Boiled green plantain retains only about 2 grams of resistant starch in the same portion.
This matters because resistant starch slows the blood sugar response after a meal. In lab testing, raw ripe plantain produced a significantly lower glucose spike between 45 and 120 minutes after eating compared to white bread. Even boiled green plantain, with less resistant starch, triggered a lower peak glucose response than white bread.
Glycemic Index by Cooking Method
How you cook a plantain changes how fast its carbs hit your bloodstream. Researchers tested three common preparation methods and found a consistent pattern: green plantains always score lower than ripe ones, and boiling produces a slightly lower glycemic index than frying.
For ripe plantains, the glycemic index values were 54 for boiled, 54 for roasted, and 56 for fried. All three land in the medium-GI range. Green plantains scored lower across the board: 44 for boiled, 46 for roasted, and 46 for fried, placing them in the low-GI category. For context, pure glucose scores 100 and white bread typically falls around 75.
The practical takeaway: if blood sugar management is a priority, choose greener plantains and boil or roast them rather than frying. Frying also adds fat and calories that the plantain itself doesn’t contain.
Other Nutrients Worth Knowing
Plantains aren’t just a carb delivery system. A single 100-gram serving provides 487 mg of potassium, which is about 10% of the daily recommended intake and comparable to what you’d get from a banana. You also get 18 mg of vitamin C from that same serving. Plantains are naturally low in fat and contain no cholesterol, making them a relatively clean source of energy-dense carbohydrate. Their potassium content is especially relevant for people who eat plantains as a dietary staple, since potassium helps regulate blood pressure and fluid balance.
Practical Carb Counts by Portion
Most people don’t weigh their plantains on a kitchen scale, so here’s how to think about portions in real life. A whole medium plantain typically weighs around 180 to 200 grams, which means you’re looking at roughly 58 to 64 grams of total carbs for the whole fruit. If you slice and cook half a plantain as a side dish, that’s closer to 30 grams of carbs, comparable to two slices of bread.
Keep in mind that preparation adds to the equation. A plain boiled plantain has the same carbs as the raw fruit, but fried plantain chips or tostones absorb oil during cooking, which doesn’t change the carb count but does increase the total calorie load. Sweet preparations like maduros (fried ripe plantains) combine the higher sugar content of ripe fruit with added oil, making them the highest-calorie version of this food.