Best Sources of Fiber for FODMAP Diet

December 28, 2025 •

4 min read

According to research, many people with Irritable Bowel Syndrome (IBS) consume less fiber than recommended, often due to concerns over triggering symptoms. Finding the best sources of fiber for FODMAP diet is crucial for gut health, as a lack of fiber can worsen digestive issues like constipation. This guide explores safe, fiber-rich foods to help you maintain a balanced and symptom-free diet.

Quick Summary

The low FODMAP diet often reduces fiber intake, but many gut-friendly, high-fiber foods exist. This guide details low-FODMAP sources of soluble and insoluble fiber, including fruits, vegetables, grains, nuts, and seeds, plus information on safe supplementation and tips for gradual incorporation to improve digestive health.

Key Points

Strategic Choices: Many high-fiber foods are high-FODMAP, requiring intentional selection of low-FODMAP alternatives to maintain sufficient fiber intake.
Balanced Approach: Integrate both soluble fibers (oats, flaxseeds) and insoluble fibers (brown rice, carrots) in appropriate low-FODMAP servings to regulate bowel movements.
Seeds are Fiber Powerhouses: Chia seeds and ground flaxseeds are among the most fiber-dense low-FODMAP options and can be easily added to various foods.
Gradual Increase: Add fiber slowly to your diet, accompanied by plenty of water, to prevent bloating and discomfort as your system adjusts.
Legumes in Small Servings: Rinsed, canned chickpeas and lentils are safe in small, specified quantities and contribute valuable fiber.
Safe Supplements Exist: If food sources are insufficient, consider low-fermentation fiber supplements like psyllium husk or PHGG, but consult a dietitian first.
Variety is Key: Eating a wide range of low-FODMAP fruits, vegetables, and grains helps ensure a diverse nutrient profile and robust gut health.

Understanding Fiber on a Low-FODMAP Diet

Many high-fiber foods, such as wheat and beans, are also high in FODMAPs, making them off-limits during the elimination phase of the diet. This can lead to a significant drop in fiber intake, which is essential for regulating bowel movements, feeding beneficial gut bacteria, and preventing long-term health issues. The key is to be strategic, choosing fiber sources that are low in FODMAPs while still providing ample nutritional benefits.

The Two Types of Fiber and FODMAPs

Fiber is typically categorized into two types: soluble and insoluble. Both are important for digestive health, but their effects differ. Soluble fiber dissolves in water to form a gel, which can help soften stools and regulate diarrhea. Insoluble fiber adds bulk to stools and helps speed up waste removal, preventing constipation. While some FODMAPs are fermentable fibers, not all fibers are FODMAPs. The goal is to choose non-fermentable or mildly fermentable fiber sources in safe serving sizes.

Top Low-FODMAP Fiber Sources

There is a wide variety of delicious and nutritious low-FODMAP foods to choose from. Incorporating a mix of these can help you meet your daily fiber goals without triggering digestive distress.

Fruits

Kiwi: Two small kiwis can provide 4 grams of fiber and are known to aid regularity.
Oranges: One medium orange offers 3 grams of fiber, with a good soluble fiber content.
Raspberries: A ⅓ cup serving of raspberries contains 3 grams of fiber.
Strawberries: A 1-cup serving of fresh strawberries provides over 3 grams of fiber.
Firm Banana: While ripe bananas can be higher in FODMAPs, a firm, unripe banana in a small serving is a great fiber source.

Vegetables

Carrots: One medium carrot is a good source of fiber, and they can be eaten raw or cooked.
Spinach and Kale: Leafy greens like spinach and kale are excellent sources of both insoluble and soluble fiber.
Green Beans: A ½ cup serving provides fiber and can be incorporated into many dishes.
Potatoes: A medium potato, especially with the skin on, is a good source of fiber.
Eggplant: A 1-cup serving of cubed raw eggplant offers 2.5 grams of fiber.

Grains, Nuts, and Seeds

Chia Seeds: One to two tablespoons of chia seeds can contain a significant amount of fiber, making them a powerful addition to smoothies or oatmeal.
Ground Flaxseeds: Ground flaxseeds are one of the highest sources of low-FODMAP fiber, often used in baking or added to yogurt.
Oats: A versatile grain, oats are safe in specific portion sizes and are a great source of soluble fiber.
Quinoa and Brown Rice: These gluten-free whole grains are excellent fiber options for meals.
Nuts: Safe nuts like almonds (10-12 nuts), walnuts, and peanuts in low-FODMAP portion sizes offer a good dose of fiber.

Legumes (in Moderation)

Canned Chickpeas and Lentils: Canned and thoroughly rinsed chickpeas or lentils in ¼ cup servings are low-FODMAP and provide valuable fiber.

Incorporating Fiber Safely

Increasing fiber intake on a low-FODMAP diet must be done gradually to allow the digestive system to adapt. A sudden increase can cause bloating and discomfort. Start with small serving sizes and gradually increase as tolerated. Hydration is also essential, as fiber absorbs water and requires plenty of fluids to work effectively and prevent constipation.

Comparison of Low-FODMAP Fiber Sources


Food Item	Primary Fiber Type	Recommended Serving Size	Common Uses	Notes
Chia Seeds	Soluble and Insoluble	1-2 tbsp	Smoothies, yogurt, oatmeal, baked goods	Highly versatile, excellent fiber density. Start with 1 tbsp to test tolerance.
Kiwi	Soluble and Insoluble	2 small fruits	Snacks, smoothies, salads	Can help with constipation. Great source of Vitamin C.
Rolled Oats	Soluble	½ cup dry	Oatmeal, baking, oat bran	High in beta-glucan, can help lower cholesterol. Stick to the recommended serving size.
Ground Flaxseeds	Soluble	1 tbsp	Smoothies, yogurt, baked goods, as an 'egg' replacer	Highest source of low-FODMAP fiber. Add to liquids to gel.
Brown Rice	Insoluble	1 cup cooked	Side dish, salads, bowls	A gluten-free whole grain staple. Good source of complex carbohydrates.
Carrots	Insoluble	1 medium	Raw snack, cooked dishes, soups	Good for gut health. High in vitamins and minerals.

How to Build a High-Fiber, Low-FODMAP Meal Plan

Integrating low-FODMAP fiber sources into your daily meals can be simple with a little planning. Focus on adding one or two fiber-rich items to each meal and snack. For breakfast, consider oatmeal with chia seeds and a small serving of raspberries. For lunch, a quinoa salad with fresh vegetables like carrots and spinach makes a great option. Dinner could feature brown rice with a stir-fry containing green beans, carrots, and tempeh. Snacks can include low-FODMAP nuts or a kiwi.

Low-FODMAP Fiber Supplements

If dietary changes are not enough, certain fiber supplements are well-tolerated on a low-FODMAP diet.

Psyllium Husk: A popular soluble fiber supplement that is low-fermentation and bulks stools. It is often recommended for IBS symptom management.
Partially Hydrolyzed Guar Gum (PHGG): A soluble, low-FODMAP fiber that is more easily digested and less likely to cause gas and bloating.

Always consult with a healthcare professional or registered dietitian specializing in FODMAPs before introducing supplements to ensure they are appropriate for your specific needs.

Conclusion

Maintaining adequate fiber intake is an essential part of managing symptoms and supporting long-term digestive health while on a low-FODMAP diet. By focusing on safe, fiber-rich foods like specific fruits, vegetables, seeds, and grains, individuals can meet their daily requirements without discomfort. The key to success is a gradual increase, prioritizing hydration, and understanding proper serving sizes. With strategic planning, a high-fiber, low-FODMAP diet can be both effective and sustainable, offering relief and promoting a healthier gut. For comprehensive guidance on managing symptoms, consulting a qualified dietitian is the best next step.

Monash University FODMAP Diet App - The definitive guide for checking the FODMAP content and serving sizes of foods.

Frequently Asked Questions

The low FODMAP diet restricts many high-fiber foods, potentially lowering your overall fiber intake. Maintaining proper fiber is important for regulating bowel movements, preventing constipation, and promoting healthy gut flora.

Soluble fiber (found in oats, kiwis) forms a gel that helps regulate diarrhea, while insoluble fiber (found in brown rice, seeds) adds bulk to stool, aiding regularity and relieving constipation. Both are beneficial when sourced from low-FODMAP foods.

Yes, but in very specific, small portion sizes. Canned and well-rinsed chickpeas and lentils are low-FODMAP in ¼ cup servings, as the rinsing process helps reduce the FODMAP content.

Yes. Safe options include psyllium husk and partially hydrolyzed guar gum (PHGG), as they are low-fermentation fibers less likely to cause gas and bloating. Always consult a healthcare professional before starting supplements.

Start with a small amount, such as one tablespoon, and mix it into a liquid like water, lactose-free yogurt, or a smoothie. Gradually increase the amount to help your digestive system adjust. Always ensure you drink plenty of fluids.

Excellent low-FODMAP vegetable sources of fiber include spinach, kale, carrots, green beans, potatoes (especially with the skin), and eggplant. These can be added to meals in appropriate serving sizes.

For some foods, FODMAPs are concentrated in the skin. However, many low-FODMAP vegetables and fruits are safe with the skin on. Always check a reliable resource like the Monash app for specific serving guidelines to see if peeling is necessary.