USDA NUTRIENT DATABASE REFERENCE

Banana Nutrition Facts

Complete macronutrient and micronutrient breakdown for raw bananas — per 100g, per medium banana, and per serving.

Complete Banana Nutrition

// PER MEDIUM BANANA (118G) — RAW, WITHOUT PEEL

Key Nutrients at a Glance

Potassium422mg · 9% DV
Vitamin B60.4mg · 25% DV
Vitamin C8.7mg · 10% DV
Dietary Fiber3.1g · 11% DV
Magnesium31.9mg · 8% DV
Folate23.6mcg · 6% DV

Bananas and Potassium

Bananas are one of the most well-known sources of dietary potassium, providing 422mg per medium banana — about 9% of the 4,700mg daily recommendation. Potassium is essential for heart function, blood pressure regulation, nerve signaling, and muscle contraction. While often marketed as potassium powerhouses, bananas are actually surpassed by foods like avocados (975mg), sweet potatoes (541mg), and spinach (540mg per cup) — but their convenience and palatability make them a popular choice.

Vitamin B6 — Bananas' Biggest Micronutrient Win

Perhaps the most impressive micronutrient in bananas is Vitamin B6 (pyridoxine), with one medium banana delivering 25% of your daily needs. B6 supports over 100 enzyme reactions in the body, plays a critical role in neurotransmitter production (including serotonin and dopamine), aids immune function, and is essential during pregnancy for fetal brain development.

Carbohydrates and Sugar

Bananas contain 27g of carbohydrates per medium fruit, with 14g being natural sugars (primarily fructose, glucose, and sucrose). Riper bananas have a higher sugar content and lower starch content. Unripe bananas have a GI of ~30, while fully ripe bananas reach ~60. People with blood sugar concerns may prefer slightly underripe bananas.

Resistant Starch & Gut Health

Underripe (green) bananas contain significant amounts of resistant starch — a type of fiber that passes through the small intestine undigested and feeds beneficial gut bacteria in the colon. This acts as a prebiotic, supporting a healthy microbiome, improving colon health, and promoting feelings of fullness.

Are Bananas Healthy?

Yes — bananas are a nutritionally dense, naturally low-fat, cholesterol-free food with meaningful contributions of several vitamins and minerals. They provide quick energy from natural sugars, sustained energy from fiber and complex carbs, and critical micronutrients like B6 and potassium. They're an excellent pre-workout snack and one of the most accessible healthy foods available globally.

Nutrition FAQs

How much potassium is in a banana?
A medium banana (118g) provides 422mg of potassium, approximately 9% of the recommended 4,700mg daily value for adults.
Are bananas high in sugar?
A medium banana contains about 14g of natural sugar. While moderate, the fiber content (3.1g) slows absorption. Riper bananas have more sugar; green bananas have more resistant starch.
How much fiber does a banana have?
A medium banana provides 3.1g of dietary fiber — about 11% of the daily recommended intake.
What vitamins are in a banana?
Bananas are richest in Vitamin B6 (25% DV), followed by Vitamin C (10% DV), folate (6% DV), riboflavin, and niacin.
Can diabetics eat bananas?
Bananas can fit into a diabetic diet in moderation. Choosing smaller or underripe bananas lowers the glycemic impact. Pairing with protein or healthy fat further slows sugar absorption.