Is banana ok on a fodmap diet? A guide to ripeness and portion size

October 12, 2025 •

3 min read

According to Monash University, the institution that pioneered the low FODMAP diet, the FODMAP content of bananas varies significantly with ripeness, affecting whether it's safe to include for those sensitive to FODMAPs. This critical detail determines if is banana ok on a fodmap diet and can be the difference between a digestive-friendly snack and one that causes discomfort.

Quick Summary

The suitability of bananas on a low FODMAP diet depends on ripeness and portion size, as unripe bananas are low in fructans while ripe ones are high. It is important to monitor consumption and choose firmer, less ripe fruit, adhering to specific serving sizes to manage gastrointestinal symptoms effectively.

Key Points

Ripeness is Critical: The FODMAP content of a banana increases significantly as it ripens, primarily due to rising fructan levels.
Stick to Small Portions of Ripe Bananas: A low FODMAP serving of a ripe common banana is about 35g, which is approximately one-third of the fruit.
Choose Firm or Unripe Bananas: A medium firm, yellow-green common banana (around 100g) is generally low FODMAP and better tolerated by those with IBS.
Consider Sugar Bananas: This smaller variety of banana is low FODMAP even when ripe, up to a medium-sized serving (112g).
Listen to Your Body's Tolerance: Even low FODMAP portions can cause symptoms for some individuals, and personal tolerance is the most important guide.
Use the Monash University App for Accurate Data: The official app provides the most current and specific lab-tested data on FODMAP content for different foods.

Understanding FODMAPs and Bananas

The low FODMAP diet, often recommended for individuals with Irritable Bowel Syndrome (IBS), focuses on reducing fermentable carbohydrates that can cause digestive issues. FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. These short-chain carbohydrates are poorly absorbed in the small intestine and can lead to bloating, gas, and abdominal pain when fermented by gut bacteria. For many foods, the FODMAP content is straightforward, but for bananas, the level changes dramatically as the fruit ripens.

The Impact of Ripeness on Banana FODMAPs

The most important factor when considering if a banana is low FODMAP is its state of ripeness. As a banana ripens, its complex carbohydrates convert into simple sugars, and its resistant starch levels decrease while its fructan content increases. Fructans, a type of oligosaccharide, are the primary FODMAP of concern in bananas. This is why the same fruit can be low FODMAP at one stage and high FODMAP at another.

Common vs. Sugar Bananas

Not all bananas are created equal, and Monash University's testing has distinguished between different types. The standard Cavendish or 'common' banana is the most prevalent variety in most supermarkets. 'Sugar' bananas, also known as lady finger bananas, are a smaller and sweeter variety. Their low FODMAP serving sizes differ, so it's essential to know which kind you are consuming.

Low FODMAP Serving Sizes

To safely incorporate bananas into a low FODMAP diet, portion control is key, especially with ripe fruit. Using a food scale to weigh your serving is the most accurate method.

For common (Cavendish) bananas:
- Firm (just yellow with no brown spots): A medium banana (approx. 100g) is considered low FODMAP.
- Ripe (yellow with brown spots): The low FODMAP serving size decreases significantly to around 35 grams, or about one-third of a medium banana, as the fructan content rises.
For sugar (lady finger) bananas:
- Firm and Ripe: Both stages are considered low FODMAP in a medium-sized serving (approx. 112g).

Potential Complications with Bananas

Even when consuming low FODMAP portions of firm bananas, some individuals might experience symptoms due to other factors.

Resistant Starch: Unripe bananas are high in resistant starch, a type of fiber that feeds gut bacteria. While beneficial for gut health, this fermentation process can produce gas and bloating in sensitive individuals.
Amines: Ripe bananas are higher in amines, which are naturally occurring food chemicals. While not FODMAPs, they can cause digestive and other symptoms in some people.

Practical Tips for Enjoying Bananas on a Low FODMAP Diet

Successfully managing your diet requires careful planning. Here are some strategies for incorporating bananas wisely:

Plan ahead: Buy bananas when they are still slightly green and use them quickly before they ripen too much.
Listen to your body: Every person's tolerance level is unique and can change over time. Experiment with small quantities and monitor your symptoms.
Freeze wisely: If your bananas are ripening too fast, peel and freeze them while they are still firm and mostly yellow. This halts the ripening process and makes them perfect for low FODMAP smoothies.
Pair with low FODMAP foods: Enjoy your portion-controlled banana with other safe ingredients like peanut butter, low FODMAP yogurt, or lactose-free kefir.

Comparison of Banana Types on FODMAP Diet


Feature	Common (Cavendish) Banana	Sugar (Lady Finger) Banana
Appearance	Medium to large size, standard yellow color when ripe.	Smaller, shorter, and thicker with thinner skin.
Taste	Mild, classic banana flavor.	Sweeter flavor than common bananas.
FODMAP (Firm)	Low FODMAP at 100g.	Low FODMAP at 112g.
FODMAP (Ripe)	Low FODMAP at 35g. High FODMAP at 100g.	Low FODMAP at 112g.
Primary FODMAP	Fructans increase significantly with ripening.	Contains fructose when ripe in larger quantities.

Conclusion: A Balanced Approach to Bananas

For those following a low FODMAP diet, the simple answer to 'is banana ok on a fodmap diet?' is a qualified 'yes.' The crucial details are the ripeness and the portion size. Unripe, firm bananas are generally well-tolerated in moderate portions, while ripe bananas must be restricted to much smaller servings to avoid high fructan content. Choosing smaller, sugar bananas can also provide a low FODMAP option even when ripe. By paying close attention to these factors and listening to your body's individual response, you can continue to enjoy the nutritional benefits of bananas without triggering uncomfortable IBS symptoms. For verified information on specific serving sizes, always refer to the official Monash University FODMAP Diet App, which is updated regularly based on lab testing.

Frequently Asked Questions

Yes, but only in a small, controlled portion. For a common banana, the low FODMAP serving is limited to about 35 grams, or one-third of a medium banana, due to its high fructan content when ripe.

An unripe banana is low in fructans and high in resistant starch, making it low FODMAP in a medium-sized portion. A ripe banana, however, has a much higher fructan content, requiring a significantly smaller serving size.

Yes, Monash University testing shows that both firm and ripe sugar bananas are low FODMAP in a medium-sized portion (112g), making them a safer choice for those who prefer ripe bananas.

Banana chips have a low FODMAP serving size of 30g, or about 15 chips. Exceeding this amount can lead to consuming a moderate or high amount of fructans.

To preserve a banana's low FODMAP status, you can store it away from other ripening fruits, wrap the stem in plastic wrap, or peel and freeze it once it reaches the desired stage of ripeness.

Green bananas contain resistant starch, which is a prebiotic fiber that ferments in the large intestine. This fermentation process can produce gas and bloating in individuals with sensitive digestive systems, even though the fruit is low in fructans.

Freezing bananas halts the ripening process, effectively locking in their current FODMAP level. You can peel and freeze firm, unripe bananas to use later in low FODMAP smoothies and recipes.