Is Banana Keto? Net Carbs in Bananas + What to Eat Instead
The Verdict First
| Total carbohydrates | 22.84 g |
|---|---|
| ↳ Sugars (included above) | 12.23 g |
| ↳ Fiber (included above) | 2.6 g |
| Calories | 89 | Protein | 1.09 g |
|---|---|---|---|
| Fat | 0.33 g | Saturated fat | 0.11 g |
| Potassium | 358 mg | Sodium | 1 mg |
| Magnesium | 27 mg | Cholesterol | 0 mg |
Source: USDA FoodData Central, SR Legacy — FDC #173944 (Bananas, raw). Net carbs = total carbohydrates − fiber. Sugars and fiber are subsets of total carbohydrates, listed for context only.
Banana is the closest no in our entire database: 20.24 g net carbs per 100 g against a keto hard line of 20 g. That 0.24 g gap is rounding-error territory, and it is worth being honest about what it means. Our standard calls a food keto when it stays at or under 5 g net carbs per 100 g, and banana is more than four times that number. On the low-carb side (20 g per 100 g), banana sits a hair past the line too, so the badge reads NO on both counts — but by the narrowest margin we have ever published. The practical read: a banana is not poison for a low-carb eater, it is simply a budget question, and the budget math almost never works out.
Two numbers explain why banana carries the carb load it does. Sugar sits at 12.23 g per 100 g (USDA SR Legacy, FDC #173944) — most of it glucose and fructose that arrive with almost no fat and only 1.09 g protein to slow them down. And fiber is just 2.6 g, so there is no meaningful subtraction from the total of 22.84 g. Bananas are also picked and eaten along a ripeness curve: the USDA figure describes an average raw banana, and a browner, softer one has converted more of its starch into sugar. The numbers we publish are the verified average, not a promise about the specific piece on your counter.
The Numbers, per 100 g of banana
The card above is pulled directly from USDA FoodData Central, never hand-copied. Three rows deserve a closer look:
First, potassium: 358 mg per 100 g (FDC #173944), about 8% of the US FDA Daily Value of 4,700 mg. This is the nutrient banana is famous for, and the fame is earned — but our data shows it is not unique. Avocado carries 485 mg per 100 g and pumpkin seeds 809 mg (both USDA SR Legacy, FDC #171705 and #170556), so the mineral argument for banana is weaker than the marketing suggests. That matters on keto, where sodium, potassium and magnesium losses in the first weeks are a real, measurable phenomenon — our keto flu and electrolytes guide covers the full mineral ledger.
Second, sugar at 12.23 g per 100 g puts banana in the same neighborhood as some soft-serve desserts, per gram. Third, calories are modest (89 kcal per 100 g) — this is not an energy-dense food, it is a carbohydrate-dense one. A medium banana weighs around 118 g peeled, which scales our verified figure to roughly 24 g net carbs for the whole fruit (our arithmetic from FDC #173944). That is a full day of keto carbohydrates for many people, spent on one item that brings little fat and protein with it.
What to Eat Instead
Banana's job in most diets is sweetness plus potassium plus portability. Every one of those jobs has a verified low-carb replacement:
Avocado — 1.83 g net carbs, 485 mg potassium per 100 g (USDA SR Legacy, FDC #171705). It beats banana on the exact mineral banana is famous for, with a third of the carbs and 15 times the fat to keep you full. Half an avocado with salt and lime is the closest thing keto has to a banana moment.
Walnuts — 2.78 g net carbs, 201 mg magnesium per 100 g (FDC #170186). For the grab-and-go snack slot, a measured handful covers the portability job and adds magnesium, a mineral most keto eaters need to track (see our net carbs guide for how we weigh portions).
Heavy cream — 2.84 g net carbs per 100 g (FDC #170859). If the craving is really about banana's creamy sweetness, whipped heavy cream with a few sliced strawberries (5.68 g net carbs per 100 g, FDC #167762) lands closer to the flavor profile than any banana product — and far under the line.
The worst possible move is processed banana. Banana bread runs 53.5 g net carbs per 100 g in our data (USDA SR Legacy, FDC #174906), nearly triple the raw fruit, because the loaf concentrates the fruit and adds flour and sugar on top. If 20.24 g was already a no, 53.5 g is not a discussion.
A Keto Recipe: Salted Cacao Avocado "Banana" Pudding
This is the pudding we make when the banana craving hits, built entirely from verified numbers:
1. Start with 150 g ripe avocado (about 2.7 g net carbs, from FDC #171705) — the riper the better, since ripeness reads as sweetness.
2. Add 60 g heavy cream (about 1.7 g net carbs, FDC #170859), 1 tablespoon unsweetened cocoa powder, and a pinch of salt. Salt is not optional: it is what convinces your palate that dessert happened.
3. Blend until glossy, then chill for 20 minutes. Sweeten to taste with a measured keto-friendly sweetener if your plan allows it.
4. Top with 15 g chopped walnuts (about 0.4 g net carbs, FDC #170186) for crunch and magnesium.
The whole bowl lands in the neighborhood of 5 g net carbs — less than a quarter of one medium banana, with potassium the banana cannot match. Each figure is our arithmetic from the cited FDC entries.
Fun Fact: How the World Eats It
In Uganda and much of East Africa, the matoke — a starchy cooking banana — is steamed in bundles and mashed like a potato, a savory staple rather than a sweet snack. In Brazil, fried banana accompanies rice and beans as a side, salted rather than sugared. And in the Philippines, saging na saba (a cooking banana variety) goes into stews and fried snack rolls. The pattern across all three: where banana is a food, it is cooked, salted and paired with protein — where banana is a dessert fruit, it is the sugary one we know, and the carb data follows.
How many net carbs in a whole banana?
A medium peeled banana weighs about 118 g. Scaling the USDA figure of 20.24 g net carbs per 100 g (FDC #173944), one medium banana carries roughly 24 g net carbs — our arithmetic from the verified per-100 g number. A large banana can exceed 28 g.
Is a banana better before or after a workout on low carb?
We publish data, not training advice. What the data shows: a banana is nearly pure available carbohydrate (20.24 g net, 12.23 g sugar per 100 g, FDC #173944) with minimal fat or protein. Whether that profile fits your plan is a question for you and, if relevant, a qualified professional — our verdicts only state where foods sit against our 100 g carb thresholds.
Are green (unripe) bananas lower in carbs?
Unripe bananas contain more resistant starch, which behaves differently from sugar in the gut. Our database carries the verified USDA average for raw banana; it does not break out ripeness stages, so we do not publish a number for green bananas. Per our data policy, no verified figure means no claim — the honest answer is that the average banana measures 20.24 g net carbs and individual ripeness varies.
How does banana compare with other fruit on keto?
Banana reads heavier than anything else in the berry-and-orchard set we price: 20.24 g net carbs per 100 g (FDC #173944) against blueberries at 12.09 g (FDC #171711), apples at 11.41 g (FDC #171688), strawberries at 5.68 g (FDC #167762) and blackberries at 4.31 g (FDC #173946). The gap to blackberries is nearly five to one. One caveat runs the other way: dried fruit and dates measure far higher than any of these, which is why we do not publish numbers for dried forms without a matching verified entry.