Are Green Bananas High or Low FODMAP?

January 14, 2026 •

3 min read

According to research from Monash University, the FODMAP content of bananas is directly tied to their ripeness. So, are green bananas high or low FODMAP? While ripe bananas are high in FODMAPs, firm, unripe green bananas are a safe and low-FODMAP choice for those managing digestive symptoms.

Quick Summary

The FODMAP content of bananas is determined by ripeness; green, unripe bananas are low FODMAP, while ripe ones are high FODMAP due to increasing fructan levels. Safe serving sizes are crucial for common varieties like Cavendish, but smaller sugar bananas offer more flexibility. Proper selection and storage are key for a happy gut on the low FODMAP diet.

Key Points

Ripeness is Key: Unripe, green bananas are low FODMAP, but their FODMAP content increases as they ripen and develop brown spots.
Serving Size is Crucial: A medium firm, green common banana (about 100g) is a safe low-FODMAP serving. A ripe common banana's safe serving is much smaller, at around 35g.
Resistant Starch: Green bananas are high in resistant starch, which is beneficial but can still cause gas in some sensitive individuals due to fermentation.
Variety Differences: Smaller sugar bananas (Lady Fingers) are generally lower in FODMAPs, with a medium-sized ripe one (112g) being low FODMAP.
Fructan Accumulation: The increase in FODMAPs as a banana ripens is due to the conversion of resistant starch into simple sugars, specifically fructans.
Cooking Green Bananas: Because of their starchy nature, green bananas are often cooked, boiled, or used to make low-FODMAP green banana flour.
Freezing for Preservation: Freezing green bananas before they ripen effectively halts the ripening process and keeps them low FODMAP for future use.

Understanding FODMAPs and Bananas

FODMAPs (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols) are a group of short-chain carbohydrates that can be difficult for some people to digest. For individuals with Irritable Bowel Syndrome (IBS), consuming high-FODMAP foods can lead to uncomfortable symptoms like bloating, gas, and abdominal pain. The FODMAP content of a banana is not static; it changes dramatically as the fruit ripens, which is why the question of are green bananas high or low FODMAP is so important.

The Ripeness Factor: Green vs. Ripe

The transformation of a banana's FODMAP profile is a direct result of its ripening process. As a banana matures from green to yellow, the resistant starch it contains is converted into simpler sugars, including a type of FODMAP called fructans.

Green Bananas (Low FODMAP): When a banana is green and firm, its carbohydrate content is mostly resistant starch. This type of fiber is not easily fermented by gut bacteria, making it a safer option for those on a low-FODMAP diet. According to Monash University, one medium, firm common banana (around 100g) is considered low FODMAP.
Ripe Bananas (High FODMAP): As the banana ripens and yellow spots appear, the resistant starch decreases, and the fructan content increases significantly. A ripe common banana (yellow with brown spots) becomes high FODMAP, with a safe low FODMAP serving size shrinking to only about 35g (approximately 1/3 of a medium banana).

Variety Matters: Common vs. Sugar Bananas

The most commonly available banana is the Cavendish, but other varieties exist with different FODMAP properties.

Common (Cavendish) Bananas: These are the long bananas typically found in grocery stores. Their FODMAP level is highly dependent on ripeness, as detailed above.
Sugar (Lady Finger) Bananas: These are smaller and sweeter. Monash University has tested these and found that unripe sugar bananas are low in FODMAPs even in larger servings, and ripe sugar bananas are low FODMAP in a medium-sized portion of 112g. This makes them a more flexible choice if you prefer a sweeter, ripe banana.

Serving Sizes: A Critical Distinction

For those on a low-FODMAP diet, portion control is just as important as the food itself. The following table provides a clear comparison of FODMAP levels based on ripeness and serving size for common bananas:


Ripeness Stage	FODMAP Content	Low FODMAP Serving Size (Common Banana)
Green / Firm	Low FODMAP	100 grams (~1 medium banana)
Ripe / Spotted	High FODMAP	35 grams (~1/3 medium banana)

Practical Tips for Incorporating Green Bananas

If you are following a low-FODMAP diet and miss bananas, choosing a green one is your best bet. Because of their starchy nature, green bananas are not typically eaten raw. They are often cooked and used in savory dishes, adding a unique texture and a more neutral flavor compared to ripe bananas.

Boiling or Steaming: This is a common cooking method for green bananas and plantains, especially in Caribbean and Latin American cuisine.
Banana Flour: Made from dried, unripe green bananas, this flour is also low FODMAP and a great gluten-free option for baking. Monash University has certified green banana flour as low FODMAP in a 100g serving.
Storage: Freezing green bananas before they ripen is an excellent way to prevent the fructan content from increasing. They can then be used later in low-FODMAP smoothies.

Potential Complications: Resistant Starch

While green bananas are low in FODMAPs, they are high in resistant starch. For most people, resistant starch is beneficial as a prebiotic fiber that feeds good gut bacteria. However, for some individuals with IBS, the fermentation of resistant starch in the large intestine can still cause gas and bloating. If you notice symptoms after eating green bananas, it's worth monitoring your intake or consulting a registered dietitian who can help you manage your tolerance.

Conclusion

The simple answer to whether are green bananas high or low FODMAP is that they are low FODMAP. The key lies in their ripeness and portion size. By choosing firm, unripe bananas and sticking to recommended serving sizes, individuals on a low-FODMAP diet can enjoy this versatile fruit without triggering symptoms. As always, listening to your body and consulting with a healthcare professional or registered dietitian is the most effective approach for managing dietary intolerances.

Note: The FODMAP content of bananas can vary slightly based on the specific variety and storage conditions. The gold standard for up-to-date information is the Monash University FODMAP Diet App.

Frequently Asked Questions

Yes, but only in very small portions. A ripe, common banana (with brown spots) contains high levels of fructans, so the recommended low-FODMAP serving is limited to about 35 grams, or approximately 1/3 of a medium banana.

To ensure a banana is low-FODMAP, it should be green and firm. A slightly yellow banana with no brown spots is also acceptable in a medium-sized serving. Once brown spots appear, the FODMAP content increases.

The main FODMAP that increases in ripe bananas is fructans, a type of oligo-saccharide. This occurs as the banana's resistant starch is converted into simpler sugars during the ripening process.

Resistant starch is a type of fiber that, unlike other starches, resists digestion in the small intestine. Green bananas are high in resistant starch, which is a key reason for their lower FODMAP rating compared to ripe ones.

Yes, sugar bananas are different. According to Monash University, both unripe and ripe sugar bananas are low FODMAP in a medium-sized serving (112g), making them a more forgiving option.

Yes, freezing a firm or slightly green banana stops the ripening process completely. You can peel and freeze bananas before they ripen to use later in smoothies or other recipes while keeping their FODMAP content low.

No, cooking a ripe banana will not reduce its FODMAP content. The fructans present in the ripe fruit are not broken down by heat, so portion control remains essential even when cooked.