How much banana can I eat on a low FODMAP diet?

October 10, 2025 •

4 min read

According to Monash University research, the FODMAP content of a common banana changes drastically with its ripeness. This means that knowing how much banana can I eat on a low FODMAP diet is critical for managing IBS symptoms, as your portion size is not a single, fixed number.

Quick Summary

This guide outlines the specific serving sizes for unripe and ripe bananas on a low FODMAP diet, explaining how FODMAP content changes during ripening. It covers key differences between common and sugar bananas, and offers tips for incorporating bananas safely into your meals and snacks.

Key Points

Unripe is Low FODMAP: Firm, yellow common bananas (up to 100g) are a safe portion for most people during the elimination phase.
Ripe is High FODMAP: As a common banana ripens and develops brown spots, its FODMAP content increases, limiting the safe serving to about 35g.
Fructans Increase with Ripeness: The main reason for the portion size difference is that the fructan levels rise as the banana matures.
Freezing Preserves FODMAP Status: To use a firm banana later in smoothies or baking, freeze it while it's still firm to lock in its low FODMAP content.
Alternative Banana Varieties: Some types, like the smaller sugar banana, may be tolerated in larger servings even when ripe; always consult updated guidelines.
Listen to Your Body: Personal tolerance varies; adjust your intake based on your own symptoms, especially after reintroduction.
Precision is Key: For ripe bananas, use a food scale to measure portions accurately and avoid symptom-triggering amounts.

Understanding the FODMAPs in Bananas

For many on a low FODMAP diet, fruit can be a source of confusion. Bananas, in particular, require careful consideration due to how their FODMAP content changes as they ripen. The main FODMAP category of concern in bananas is fructans (oligosaccharides). As a banana matures from firm and green to soft and brown-spotted, its resistant starch is converted into simple sugars and fermentable fructans, significantly altering its FODMAP profile.

This is why serving size is not a one-size-fits-all rule. A firm, just-ripe banana is suitable in a much larger quantity than an overripe one. To manage symptoms effectively, followers of the diet must learn to differentiate and measure their portions based on this ripeness factor.

The Common (Cavendish) Banana: Serving Sizes by Ripeness

The Cavendish banana is the most widely available variety in grocery stores. Your tolerance for this type of banana on a low FODMAP diet is directly linked to its stage of ripeness. Here’s a breakdown based on the latest guidelines from Monash University:

Unripe/Firm (green to just yellow): A serving of 100 grams is low in FODMAPs. This is roughly one medium banana. At this stage, the banana is high in resistant starch and low in fructans. Even at 110 grams, it only reaches a moderate level of fructans.
Ripe (yellow with brown spots): A low FODMAP serving shrinks dramatically to just 35 grams, which is about one-third of a medium banana. By this stage, the fructan content has increased significantly. Consuming larger portions, such as a full 100-gram banana, is considered high FODMAP.

What About Other Banana Varieties?

Beyond the standard Cavendish, other banana types, like the smaller sugar or Lady Finger bananas, have different FODMAP profiles. Firm sugar bananas are low FODMAP in much larger servings, up to 112 grams (one medium banana), and sometimes even larger. Some individuals may also tolerate ripe sugar bananas in larger portions than ripe Cavendish bananas. Always check the most recent data from a trusted source like the Monash University FODMAP Diet App for confirmation on specific types.

Comparison Table: Common Banana Ripeness vs. FODMAP Content

To help visualize the difference, the following table compares the FODMAP status of common bananas at different stages of ripeness based on Monash University testing:


Ripeness Stage	Appearance	Low FODMAP Serving Size	Primary FODMAP	Safe Serving Notes
Unripe / Firm	Green to fully yellow, no spots	1 medium banana (100g)	Resistant Starch	Higher portion size safe for most individuals during the elimination phase.
Ripe	Yellow with brown spots	1/3 medium banana (35g)	Fructans (Oligos)	Increased FODMAP content requires strict portion control.
Overripe	Mostly brown, very soft	May not be suitable	Fructans (Oligos)	Highest FODMAP concentration; best to avoid during elimination.

Practical Tips for Enjoying Bananas on a Low FODMAP Diet

Incorporating bananas into your low FODMAP meal plan requires mindfulness and preparation. Here are some strategies:

Freeze them early: If you love adding bananas to smoothies, peel and slice firm, just-yellow bananas and freeze them in a sealed container or bag. This halts the ripening process and keeps their FODMAP content low.
Time your purchase: Buy bananas when they are still slightly green and eat them within a few days, before they develop too many brown spots. This is a simple way to ensure they stay within the safe 100-gram portion size.
Measure your portion: For ripe bananas, use a kitchen scale to accurately measure out a 35-gram portion. This prevents accidental overconsumption of fructans that could trigger symptoms.
Pair with low FODMAP foods: Create balance by combining your banana portion with other low FODMAP ingredients. For instance, add sliced firm banana to a serving of lactose-free yogurt or gluten-free oatmeal.
Listen to your body: Personal tolerance can vary. Even within the low FODMAP guidelines, some individuals may have a higher or lower tolerance for bananas. Pay attention to how your body responds and adjust your portion size accordingly, especially during the reintroduction phase.

Conclusion

Managing banana consumption on a low FODMAP diet is all about controlling portion size and monitoring ripeness. An unripe or firm common banana is a safe and delicious option when kept to a 100-gram serving. A ripe banana, however, must be limited to just one-third of a medium banana (around 35 grams) due to its significantly higher fructan content. By paying attention to these details and freezing firmer bananas for later use, you can continue to enjoy this popular fruit without triggering unwanted IBS symptoms. Remember that the low FODMAP diet is not for life, and the goal is to discover your personal tolerance levels for different FODMAP groups. For a comprehensive guide and up-to-date food data, consider using the official Monash University FODMAP Diet App.

Frequently Asked Questions

No, a whole ripe common banana (100g) is considered high in fructans, a type of FODMAP. To stay within low FODMAP limits, you must restrict your serving to approximately one-third of a medium banana (around 35g).

A banana is considered unripe or firm when its skin is green to just yellow and it has no brown spots. This is the ideal stage for consuming a medium-sized banana (100g) on the diet.

As a banana ripens, its resistant starch is converted into simple sugars and fermentable fructans. This process increases the fructan content, which is why ripe bananas have a much smaller low FODMAP serving size.

Yes, banana chips are low FODMAP, but only in a very small portion. According to Monash University, a serving of 30 grams (about 15 chips) is low FODMAP. Larger amounts contain moderate levels of fructans.

Yes, you can, but the FODMAP content is based on the banana's ripeness when frozen. It is best to freeze firm, just-ripe bananas to ensure they remain low in FODMAPs for use in smoothies.

For firm sugar bananas, a 112-gram serving (1 medium banana) is low FODMAP. Ripe sugar bananas also have a low FODMAP portion of 112 grams, but it's important to confirm the latest guidelines as some data shows higher fructose in large serves.

Yes, you can have more than one low FODMAP portion in a day, but it is recommended to space them out to allow your digestive system time to process them. Listen to your body and how it reacts to multiple servings.