What Happens to Your Blood Sugar When You Eat a Banana

Bananas, while rich in vitamins and minerals, as well as fiber and antioxidants, are naturally high in sugar, which can increase blood sugar levels. But paying attention to ripeness and making some adjustments can help prevent spikes while still enjoying the fruit.

A banana’s effect on blood sugar depends on its fiber and sugar content, and both of these depend on the ripeness of the banana.

As bananas ripen, their fructose, glucose and total sugar content increases, which increases blood sugar levels.

Meanwhile, unripe bananas contain more fiber than ripe bananas. These levels can vary widely: one study showed that, per 100 gram serving, unripe bananas contain 18 grams of fiber, ripe bananas contain 4 to 5 grams, and overripe bananas contain only 2 grams.

The fiber content of fruits also influences the extent to which fruits increase blood sugar levels. Fruits high in fiber tend to have a lower glycemic index (GI). Low GI fruits, such as bananas, when unripe or slightly ripe, do not raise blood sugar as much as high GI fruits.

Here’s what you can expect from a 115 gram ripe or slightly ripe banana:

• Calories: 113
• Fat: 0.3 grams (g)
• Protein: 0.9g
• Carbohydrates: 26.4g
• Fiber: 2g
• Sugar: 18.2g

People with diabetes can eat fruits, especially bananas. Fruits contain sugar but also provide vitamins, minerals and antioxidant compounds. Bananas are also a good source of fiber, which can help lessen its effects on blood sugar.

A high fiber intake may also improve insulin and hA1c (a blood sugar marker) levels in people with diabetes. It is also linked to a lower risk of type 2 diabetes and its complications.

People with diabetes may want to choose smaller, less ripe bananas and stick to one per session. They can also pair fruit with a protein or fat source, such as nuts or plain yogurt, to reduce the glucose spike.

How much bananas you can eat (and how often you eat them) depends on your individual calorie and nutrient needs and whether you’re monitoring your blood sugar.

If you’re looking to reduce your risk of a blood sugar spike after eating a banana, here’s how to do it:

• Eat your banana with some protein and fat. Fruits eaten with a balanced meal can help support blood sugar management.
• Choose unripe or slightly unripe bananas. Ripe and overripe bananas contain more sugar and less fiber than unripe or slightly underripe bananas.
• Pay attention to portion sizes. Eating a large banana (or several bananas) will raise your blood sugar levels more than eating a smaller banana.