Bananas are a fruit on a mission to become your favourite snack: tasty, rich in carbohydrate to supply the energy you need, and already wrapped.

What is not to love?

If you have wondered how many calories are in a banana or what benefits it offers your health, our sports nutritionists have the answers.

How many calories are in 100 grams of banana?

When we refer to 100 grams of banana, we exclude the skin.

Banana calories

100 grams of banana contain 132 calories

Banana macronutrients

100 grams of banana provide the following macros:

Protein: 1 g – 4 kcal – (3 %)
Carbohydrate: 32 g – 128 kcal – (97 %)
Fat: 0 g – 0 kcal – (0 %)

Banana micronutrients

Bananas have a varied micronutrient profile.

Vitamins

Vitamin B1 (thiamin): 0.052 mg
Vitamin B2 (riboflavin): 0.054 mg
Vitamin B3 (niacin): 0.686 mg
Vitamin B5 (pantothenic acid): 0.26 mg
Vitamin B6 (pyridoxine): 0.299 mg
Vitamin B9 (folic acid): 22 micrograms
Vitamin B12 (cyanocobalamin): 0 micrograms
Vitamin C: 18.4 mg
Vitamin A: 0 micrograms
Vitamin D: 0 micrograms
Vitamin E: 0.14 micrograms
Vitamin K: 0.7 micrograms

Minerals

Calcium: 3 mg
Iron: 0.6 mg
Magnesium: 37 mg
Zinc: 0.14 mg
Sodium: 4 mg
Potassium: 499 mg
Phosphorus: 34 mg
Selenium: 1.5 micrograms

How much does a banana weigh?

A banana weighs around 150 g, giving the following macros and calories for a medium fruit:

Calories: 209
Protein: 2 g – 8 kcal – (4 %)
Carbohydrate: 48 g – 192 kcal – (92 %)
Fat 1 g – 9 kcal – (4 %)

Is eating bananas good for you?

Yes. This healthy fruit provides fibre and micronutrients in a convenient, portable package.

If you have watched Rafa Nadal play, you will know that bananas are a popular fruit in sport.

A major role is supplying energy through easily digested carbohydrates. This can make bananas useful:

Before training to help top up glycogen stores.
During training to supply energy and support performance.
After training to support muscle recovery.

Their fibre type and amount influence carbohydrate absorption, helping provide a gradual release rather than sharp blood glucose rises. However, ripeness matters. A greener banana contains more starch, a complex carbohydrate, while ripe bananas contain more sugars, or simple carbohydrates.

The more simple carbohydrate present, the sweeter the banana and the faster its absorption can be. Blending it into a smoothie can also change how quickly its carbohydrates are absorbed.

Bananas also supply potassium, relevant to normal muscle function and discussion of muscle cramps. Eating a banana can raise blood potassium, but not immediately: changes may take 30–60 minutes. If used as part of a plan to reduce cramp risk, it makes more sense before training or in the early stages than right at the end.

Why do people say bananas are fattening?

Their energy content is higher than that of many other fruits, but this does not make bananas inherently fattening. They are a healthy food that can fit into many eating patterns.

A banana simply contains the calories it contains. Weight gain or loss depends on your overall diet and how it matches your body’s needs, rather than whether you eat bananas.

How many bananas can you eat each day?

Bananas contain no inherently harmful ingredient requiring a universal restriction, so there is no single daily limit for everyone.

Variety still matters. Different fruits provide different vitamins and minerals, and a varied diet helps supply a wider range of micronutrients.

An appropriate quantity depends on factors such as exercise, your goal and how the rest of your diet is planned.

What is the best time to eat bananas?

They are versatile enough to eat whenever best suits your day.

If your aim is better sporting performance, bananas can help supply energy for training. Eat them before, during or after a session, according to your needs.

Can you eat bananas at night?

Absolutely. Your body does not turn bananas, or other fruit, into poison after a certain hour.

If they fit your nutrition plan, there is no reason to exclude them late in the day. If you train early the next morning, they may be a useful option for preparing your energy intake.

A professional can assess your goals and needs and create a plan for you.