High Fiber Low FODMAP Foods: How to Get Enough Fiber on an IBS Diet

Most people in the United States don't get enough fiber, and if you have irritable bowel syndrome (IBS), it can be even more difficult to find high-fiber foods that don't trigger your symptoms. However, a low-fiber diet is not ideal for long-term gut health, so it's important to find ways to incorporate low FODMAP fiber sources into your diet.

Since many people with IBS use a low FODMAP approach to manage their symptoms, it can be hard to meet your fiber requirements without careful planning during the elimination phase of the diet. This article will review why it's so challenging to get enough fiber on a low FODMAP diet, the difference between soluble and insoluble fiber, the best high-fiber, low FODMAP foods to choose, and tips for increasing your fiber intake without triggering IBS symptoms. 

Why Fiber Is Harder to Get on a Low FODMAP Diet

FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. These rapidly fermentable short-chain carbohydrates are common triggers for symptoms like gas, bloating, and abdominal pain in people with IBS. 

Here are some common high-fiber, high FODMAP foods that may trigger some people's symptoms:

• Beans and lentils 

• Wheat products 

• Certain fruits, including apples, pears, and stone fruits

• Fructan-rich vegetables, including garlic and onions

But while eliminating these foods can help with symptom management, it often unintentionally reduces fiber intake as well. 

Why Fiber Is So Important for IBS

Limiting fiber to manage IBS symptoms is understandable; many high-fiber foods are also high FODMAP, and we know that FODMAPs are a very common IBS trigger. But the reality is, fiber is incredibly important for people with IBS because it:

• Supports regular bowel movements

• Feeds the beneficial microbes in your gut

• Can improve stool consistency

• Is associated with numerous long-term health benefits

If you have IBS, fiber is not the enemy. However, it's important to be strategic with both the amount and type of fiber you add to your diet. That said, it is absolutely possible to add fiber-rich foods to your diet while maintaining symptom relief.

Soluble vs. Insoluble Fiber on a Low FODMAP Diet

There are two main types of fiber: soluble and insoluble. Soluble fiber forms a gel when mixed with water, and many types of soluble fiber are fermentable and act as fuel for your gut microbiome. In contrast, insoluble fiber does not form a gel or act as a prebiotic; instead, it mechanically stimulates the digestive tract and helps keep things moving smoothly. We'll review each type of fiber in detail below.

Soluble Fiber 

Because soluble fiber forms a gel in the digestive tract, it's often better tolerated than insoluble fiber. Soluble fiber has many health benefits, including:

• Softening stool

• Improving stool consistency in people with IBS-D

• Reducing cholesterol levels in the blood

• Regulating blood sugar levels

• Feeding the gut microbiome, leading to the production of short-chain fatty acids (SCFAs), which are important for overall gut health

While it's true that many types of soluble fiber are fermentable, slowly fermentable soluble fibers are usually well-tolerated by people with IBS. Some examples of well-tolerated, high soluble fiber foods include:

• Oats (up to ½ cup raw)

• Chia seeds (up to 2 tablespoons)

• Ground flax (up to 1 tablespoon)

• Psyllium husk

As with any type of fiber, it's important to add soluble fiber to your diet slowly to minimize digestive side effects such as gas and bloating. 

Insoluble Fiber 

Since insoluble fiber mechanically stimulates the digestive tract, it can be irritating to some. That said, it adds bulk to stool and speeds up digestion, which can be beneficial for people with IBS-C.

However, if you have IBS-D, insoluble fiber may worsen your symptoms because it speeds up the passage of food through the digestive tract. If you're currently in the middle of an IBS-D flare, it's generally best to stick with foods higher in soluble fiber, which help absorb excess fluid from your stool and may help normalize the consistency of your bowel movements. 

High Fiber Low FODMAP Foods

Now, the information you've been waiting for: a comprehensive list of high-fiber, low FODMAP foods to help boost your fiber intake while minimizing digestive discomfort. Keep in mind that while many low FODMAP foods are high in fiber, it's important to stick to recommended serving sizes, as some can become high FODMAP in larger portions.

High Fiber Low FODMAP Vegetables

Some people find that cooked vegetables are easier to tolerate. If you notice that raw vegetables trigger your symptoms, try cooking methods like steaming or roasting, which helps break down some of the hard-to-digest fiber.

High Fiber Low FODMAP Fruits

Kiwi is especially helpful if you struggle with constipation, as studies show eating two kiwi a day can improve constipation.

High Fiber Low FODMAP Grains

Whenever possible, choose whole grains, as they contain a lot more fiber than refined grains.

High Fiber Low FODMAP Nuts & Seeds 

When it comes to nuts and seeds, portion size is critical, as eating more than the recommended serving can quickly turn a low FODMAP food into a high-FODMAP portion.

Sample High Fiber Low FODMAP Day

Increasing your daily fiber intake doesn't mean overhauling your entire diet. Instead, think of how you can add high-fiber low FODMAP foods to the meals you already eat. 

Here are some examples:

• Breakfast: Make overnight oats with chia seeds and top with sliced strawberries and a drizzle of maple syrup.

• Lunch: Enjoy a quinoa bowl with sautéed spinach and carrots, topped with grilled chicken.

• Snack: Top lactose-free yogurt with sliced kiwi and walnuts.

• Dinner: Serve brown rice with grilled salmon and steamed green beans.

This sample low FODMAP meal plan shows that you can include a wide variety of different high-fiber foods without FODMAP stacking.

How to Increase Fiber Without Triggering IBS Symptoms 

One of the main problems I see when people add fiber to their diets is gas and bloating. However, there are several strategies you can use to minimize digestive discomfort when transitioning to a high-fiber diet: 

• Increase fiber slowly: Instead of immediately increasing your fiber intake to the recommended level, start by adding 2-3 grams every few days to give your digestive system a chance to adjust.

• Drink enough fluids: Staying hydrated helps keep things moving smoothly through your digestive tract, which is especially important when increasing your soluble fiber intake (remember, soluble fiber absorbs water, so if you're not adequately hydrated, it can worsen constipation).

• Avoid fiber “stacking”: Don’t add multiple high-fiber foods in one meal initially; instead, spread your fiber intake evenly throughout the day 

• Watch for hidden FODMAP fibers: High-fiber packaged foods often contain inulin, chicory root, and fructo-oligosaccharides (FOS), which are high in FODMAPs. Always check the label to ensure you're not accidentally eating high FODMAP fibers.

• Try low FODMAP fiber supplements: Psyllium husk and partially hydrolyzed guar gum (PHGG) are generally well-tolerated soluble fibers that can improve stool consistency. 

• Gradually reintroduce higher FODMAP fibers: Some people can tolerate small amounts of legumes (which include beans, chickpeas, and lentils), but that tolerance is individual. Generally speaking, canned, drained, and rinsed legumes are better tolerated because the canning process leaches FODMAPs into the liquid, which are removed when you drain and rinse them.  

How FODZYME Can Support Fiber Flexibility 

Even if you follow the tips above, additional tools like FODZYME can help support fiber tolerance. FODZYME makes food easier to enjoy using an enzyme blend that breaks down FODMAPs into more digestible carbohydrates. While it does not replace a low FODMAP diet, it can be a supportive tool for people with sensitivity to high-FODMAP foods who want to increase their intake of high-fiber foods while limiting digestive discomfort.

Try FODZYME today.