20 Healthy low FODMAP high fibre foods

Fibre may not be a sexy nutrient, but it IS an essential one for managing irritable bowl syndrome. It’s time to make low FODMAP high fibre foods staples in your diet, and I’ll show you how in this post.

What is fibre?

Fibre is a type of carbohydrate that the human body cannot digest and absorb.

As a carbohydrate, fibre is found in plant foods like nuts and seeds, legumes and beans, fruits, vegetables, and grains. It is also found in food products made from these plants like peanut butter, hummus, pasta, breads, plant-based milks, flours, etc.

Fibre is not found in meat, fish, eggs, or dairy.

Types of fibre

You’ve probably heard of “soluble fibre” and “insoluble fibre” right? But what exactly does that mean and which type is the best?

Soluble fibre attracts and holds water, and thereby creates a gel in the gut. It helps to sop up extra fluid in the gut and soften stool. As a result, it helps to improve both diarrhea and constipation.

Insoluble fibre does not hold water, but it does create bulk for increasing stool mass and accelerating transit through the gut. Increasing insoluble fibre doesn’t improve diarrhea, and it tends to be highly fermentable which leads to gas.

Another characteristic of fibre that is super pertinent to our discussion here is the fermentability of the fibre. This is where the low FODMAP diet comes in…

Low FODMAP foods tend to ferment less in the colon, resulting in less gas production by the microbiota. High FODMAP foods tend to ferment more readily and quicker, resulting in more gas production.

Gas can get trapped in our gut if we have slow intestinal motility or constipation, and it can exert pressure on the intestinal walls which can trigger pain in IBS due to the hypersensitivity of the colon.

Foods are complex, so they contain a mixture of soluble and insoluble, highly fermentable and minimally fermentable fibres in them. When we say something is a good source of soluble fibre, it means there’s more soluble fibre than most foods or there’s more soluble fibre relative to the insoluble fibre. I make note of good sources of soluble low FODMAP fibre below.

Fibre and the low FODMAP diet

During the elimination phase of the low FODMAP diet (LFD), moderate and high FODMAP foods are cut out. Because many of these foods are good sources of fibre, the low FODMAP diet can be lower in fibre than what is ideal.

Why does fibre matter?

1. General health: Research has found that fibre may:

• improve cholesterol
• improve blood sugars
• promote fullness
• stimulate gut motility
• reduce risk of diverticular disease and colorectal cancer.

2. Bowels: If you have IBS-C and embark on the LFD without eating enough fibre, you run the risk of exacerbating your backed up bowels.   Being FOS (full of shit) is a ticket to gas and bloating hell (believe me, I know!).  Constipation symptoms may mask any benefit from the LFD and lead you to mistakenly think the diet didn’t work.

3. Microbiome: The fibre in high FODMAP foods is the fuel your intestinal bacteria thrive on. When these gut bugs ferment fibre, they produce short-chain fatty acids (SCFAs) that help support gut health. Some research has found that the low FODMAP diet can reduce health-promoting gut bacteria, so it’s important to make sure the little critters have a good source of food.

How much fibre do you need?

• Adequate intake for women is 25 grams of fibre per day.
• Adequate intake for men is 38 grams of fibre per day.

These figures aren’t meant to be prescriptive. In fact, there is insufficient evidence to determine strict recommendations for fibre. Instead, the recommendations merely indicate the amount of fibre consumed by healthy individuals based on observed or experimental data.

In the real world, fibre requirements vary from person to person. Some people can’t handle much fibre while others can consume 40+ grams of fibre per day and still struggle to have bowel movements.

Generally, if your fibre intake is below 20 grams per day and you struggle with constipation, it’s worthwhile to slowly increase your fibre and see how your gut responds.

If you need help figuring all this out, check out my services page to see if I can support you in improving your gut symptoms.

20 Low FODMAP high fibre foods

The portions listed below are low FODMAP per the Monash University FODMAP app. Fibre amounts are derived from the Canadian Nutrient File and GoGo Quinoa website.

Fruit

• Kiwi (2 small-medium = 4 g of fibre) – 2 per day has been found to improve bowel regularity
• Raspberries (1/3 cup = 3g)
• Navel orange (1 orange = 3g) – good source of soluble fibre
• Prickly pear (1 pear = 4g)

Vegetables

There aren’t many fibre superstars in the vegetable group I’m afraid.  Most vegetables have about 1 – 2 grams of fibre per 1/2 cup chopped and cooked. 

General healthy eating guidelines encourage people to fill half their plate with vegetables and fruits. Practically speaking, many dietitians will advise people to fill half their plate at lunch and supper with vegetables. This adds up to about 2 cups which is roughly 4 servings of vegetables per day, or 4-8 grams of fibre per day.

Low FODMAP vegetables that contain soluble fibre include:

• Broccoli florets, cooked (1/2 cup = 2g)
• Carrots, raw (1 medium = 2g)
• Parsnips, raw (1 medium = 3g)
• Sweet potato, raw (1/2 cup chopped = 2g)

Nuts & Seeds

• Peanuts (1/4 cup = 3g)
• Flax seeds (2 Tbsp = 4g)
• Chia seeds (1-2 Tbsp = 4-8g) – high in soluble fibre
• Pumpkin seeds (1/4 cup = 4g)

Beans & Legumes

• Canned and rinsed red lentils (1/4 cup = 2g) – good source of soluble fibre.
• Canned and rinsed chickpeas (1/4 cup = 2g)
• Tempeh (100g = 3g)
• Edamame (1/2 cup = 4g)

Grains, breads, pastas

• Oats (1/2 cup dry = 4g) – good source of soluble fibre
• Oat bran (30g, which makes 3/4 cup cooked = 3g) – good source of soluble fibre
• Buckwheat (1/2 cup = 3g)
• Brown rice (1 cup cooked = 3g)
• Quinoa (1/2 cup cooked = 3g)
  • Check out this lemony quinoa salad recipe
• Gluten-free quinoa pasta (1 cup dry = 7g)
• Whole grain / high fibre gluten-free breads, crackers, pastas

Label reading tips

Processed gluten-free breads, pastas and crackers are traditionally made from low fibre foods like white rice, corn or potato. There are more high fibre gluten-free products these days but they may contain ingredients that are high FODMAP, like inulin.

1. Check the Nutrition Facts Table for fibre

• If the % DV (percent daily value) is 15% or more, the product has “a lot” of fibre in the serving size listed, which is good.
• If the % DV is 5% or less, it has “a little”, which is not ideal.

2. Check the ingredients list

• If you see “inulin” in the ingredients list, put the item back on the shelf and slowly back away. Inulin is a high FODMAP fructan that’s added to foods to boost fibre.

Tips for enjoying low FODMAP high fibre foods

• Grain products: Aim for at least 10% DV or higher per serving
• Fruit: Snack on low FODMAP fruit, add raspberries to oatmeal, yogurt and salads
• Vegetables: 1 cup of low FODMAP vegetables at lunch and supper
• Beans and legumes: Add canned and rinsed lentils and chickpeas to salads, casseroles, pastas, soups
• Seeds: add chia seeds or flax seeds to oatmeal, yogurt, low FODMAP smoothies, salads
• Nuts: snack on nuts, add them to salads and cereal
• Tempeh: replace chicken in a stir-fry with tempeh
• Buckwheat: replace barley in soup with buckwheat groats
• Gluten-free pasta: choose quinoa pasta instead of corn pasta
• Oat bran: make gluten-free oat bran muffins with walnuts and blueberries

Slow, Low and H2O: Gradually increasing fibre

Increasing fibre should be a gradual process accompanied by plenty of water to minimize abdominal symptoms like gas, bloating, and constipation. Here’s a 4-week plan:

• Week 1: Start by having a high fibre breakfast every morning
• Week 2: If you’re not eating 2-3 fruit + 4-5 servings of vegetables per day, increase by 1 fruit or veg every 5 days.
• Week 3: Replace low fibre snacks with higher fibre options like low FODMAP fruit and nuts
• Week 4: Replace a refined grain (typically low in fibre) with a whole grain. For example, swap our corn-based gluten-free pasta for quinoa pasta.

Fluids / Water

As you increase fibre, you need to drink enough fluid to keep your stool from drying out and making it harder to ‘drop the kids off at the pool’.

All fluids count, from water to juice, milk to coffee (yes, coffee counts towards your daily fluids!).

Aim for roughly 2000mL of fluid per day. Drink more if the weather has been hot, you’ve been physically active, or you have a larger body.

You’re likely imbibing enough fluids if your urine is a light yellow colour.

Sample meal plan for a low FODMAP high fibre day

Breakfast

• Oatmeal (1/2 cup raw oats) cooked in lactose-free milk (4g)
• 1/3 cup raspberries (3g)
• 1 Tablespoon chia seeds (4g)

Lunch (pasta salad)

• 1 cup cooked quinoa pasta (5g)
• 1 cup cooked vegetables (spinach, yellow pepper, roma tomato) (2g)
• 5 oz chicken breast (0g)
• Creamy balsamic dressing (0g)

Supper (tofu teriyaki stir fry)

• 1 cup brown rice (3g)
• 1 cup cooked vegetables (carrots, bok choy, broccoli heads, bean sprouts) (4g)
• 1/2 cup cubed firm tofu (1g)
• Teriyaki sauce recipe (0g)

Snacks

• 1 navel orange (3g)
• 2 small kiwi (4g) + 30 grams of peanuts (2g)

Total fibre: 35 grams (your gut bugs are gonna love you!)

Remember – getting enough low FODMAP high fibre foods on the LFD will help minimize symptoms that could arise from constipation so you’ll be able to feel the true effect of the diet.

Confused? Got questions? Drop me a line in the comment section 🙂

xoAndrea, RD, MHSc