Answer: Bananas are not keto-friendly, with 24 g of net carbs in a medium banana.
There are about 105 calories in a medium-sized banana. Of that, around 27 g come from carbs. With 3 g of fiber, their net carb count comes out to 24 g per banana.
The type of carbohydrates in bananas change as the fruit ripens. When the banana is green, the carbs are mainly starches. As the fruit matures, the starch converts to the sugars sucrose, fructose, and glucose.
Bananas are a great example of a healthy food that's inappropriate for the keto diet. They're a good source of potassium, vitamin B9, vitamin C and manganese but are too high in carbs to be keto.
If you're after a keto-friendly alternative to a banana, reach for an avocado. It has a similar texture but replaces the excess carbs with fiber and healthy fats.