Have you ever had a delicious meal only to feel bloated, gassy, or generally uncomfortable afterward? You may be experiencing FODMAP intolerance, a sensitivity to certain carbohydrates. Many people with irritable bowel syndrome (IBS) have a FODMAP intolerance, and it can make traveling and eating out difficult.

Wondering if you might be FODMAP-sensitive and how to manage it? Here's everything you need to know about these carbs, the types that commonly trigger symptoms, and how to easily navigate a low-FODMAP lifestyle.

What is FODMAP Intolerance?

Before diving into FODMAP intolerance, it's important to understand what FODMAPs are.

FODMAPs stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. They are short-chain carbohydrates found in certain foods, including certain fruits, vegetables, dairy, whole grains, and sweeteners. It's important to note that FODMAPs aren't "bad." In fact, certain FODMAPs are prebiotics that the good gut bacteria feed on. However, FODMAPs can cause digestive problems for certain groups of people.

Here are the main types of FODMAPs that people struggle with:

  • Galacto-oligosaccharides (GOS)
  • Fructans
  • Lactose
  • Excess fructose
  • Sorbitol
  • Mannitol

The human body doesn't digest these small carbohydrate molecules, as we lack the enzymes to do so. Instead, they move from the small intestine to the large intestine undigested. They then get fermented by the gut bacteria, which produces gas. Certain FODMAPs, such as sugar alcohols like sorbitol and mannitol, also pull water into the bowels.

People with FODMAP sensitivity, such as those with IBS, develop IBS symptoms when they eat foods containing FODMAPs. This is known as a FODMAP intolerance.

Common symptoms of FODMAP sensitivity

Most symptoms of FODMAP intolerance are digestive, and include:

  • Bloating
  • Gas
  • Abdominal pain
  • Diarrhea
  • Constipation

Symptoms can vary based on a person's individual FODMAP tolerance and which FODMAPs trigger their symptoms. For example, if you have lactose intolerance and are sensitive to lactose, you may experience abdominal pain, gas, bloating, and diarrhea.

How FODMAPs affect the digestive system

As mentioned, when FODMAPs enter the large intestine, they get fermented by the gut bacteria, which produces gas. Some FODMAPs, such as sugar alcohols, also pull water into the bowels. For most people, this fermentation and water-pulling doesn't cause any issues. But for people with IBS who may have a FODMAP intolerance, it can cause a lot of problems.

It's important to note that IBS is one of the most common functional gastrointestinal disorders. That means that, unlike gut disorders like inflammatory bowel disease, the digestive system appears normal. However, despite appearing normal, the digestive system doesn't function as it should. 

Problems with FODMAPs occur because people with IBS have visceral hypersensitivity, which means that they have an extra-sensitive digestive system. When FODMAPs produce gas and introduce extra water into the bowels, this pushes on the walls of the intestines, which can cause pain and digestive symptoms like diarrhea.

The Difference Between FODMAP Intolerance and Sensitivity

The terms FODMAP intolerance and FODMAP sensitivity can be used interchangeably. However, FODMAP intolerance is the more accurate term, as it implies that symptoms are caused by how the body processes something in the digestive tract (in this case, FODMAPs).

Identifying your trigger foods

Since so many foods contain FODMAPs, it can be tricky to identify which ones are causing your symptoms.

One of the best ways to identify trigger foods is a structured elimination diet, followed by a systematic reintroduction of high-FODMAP foods. This is called the low-FODMAP diet and will be explained in more detail below.

Another way to identify your trigger foods is to keep a detailed food diary. Take note of what you eat, portion sizes, and any symptoms. This can help you and a registered dietitian understand which foods trigger your symptoms. 

Testing for FODMAP intolerance

While there isn't a direct test for FODMAP intolerance, the low-FODMAP diet is widely used to assess and manage symptoms.

In addition, your doctor may use tests to rule out other digestive issues that mimic FODMAP intolerance, such as small intestinal bacterial overgrowth (SIBO) and celiac disease.

Overall, the structured reintroduction of FODMAP groups is the most effective way to confirm whether you have a FODMAP intolerance. This approach is typically more accurate than any FODMAP intolerance testing currently available.

Managing FODMAP Intolerance

One of the best ways to manage a FODMAP intolerance is following a low-FODMAP diet. Contrary to popular belief, the low-FODMAP diet doesn't mean eliminating high-FODMAP foods forever. Rather, it's a diet with three distinct phases.

The low-FODMAP diet explained

The first phase of the low-FODMAP diet is called the elimination phase, which involves eliminating all high-FODMAP foods. This phase typically lasts between 2–6 weeks and is done to relieve symptoms and determine whether you're sensitive to FODMAPS. During this phase, you'll avoid high-FODMAP foods and instead focus on eating a wide range of low-FODMAP foods.

The next phase of the low-FODMAP diet is called the reintroduction phase. This is one of the most important phases of the low-FODMAP diet because it allows you to identify which specific FODMAPs are causing issues. Remember, there are different types of FODMAPs. Rarely is someone sensitive to all FODMAPs, so this phase is important for identifying the FODMAP groups that are your biggest triggers.

During the reintroduction phase, you'll systematically reintroduce FODMAPs group by group. For example, you may decide to reintroduce lactose-containing foods first. On the first reintroduction day, you'll eat a small portion of a lactose-containing food. If you don't get any symptoms, you'll eat a larger portion of the same food the next day. 

Depending on the typical serving size of the food you're testing, you may do a third reintroduction with a larger portion on the third day. If you don't experience symptoms, you're likely not intolerant to that group of FODMAPs.

If you develop symptoms during reintroduction, return to eating low-FODMAP for a few days to get your symptoms under control. Then, re-test the food with which you developed symptoms. This step is essential, as people with IBS can often develop gut symptoms due to non-food factors like stress. It's important to know whether you're truly intolerant to a certain FODMAP or whether your symptoms were caused by something else.

The reintroduction phase can take 4–8 weeks to complete, depending on whether you develop symptoms related to the FODMAPs you're testing. Keeping the rest of your diet low-FODMAP during the reintroduction phase is key – otherwise, how will you know which type of FODMAP caused your symptoms?

Finally, once you've finished the reintroduction phase of the diet, you'll move on to the maintenance or personalization phase. This is how you'll eat long-term. Instead of avoiding all FODMAPs, you'll just avoid the ones that gave you symptoms during the reintroduction. For example, if you developed symptoms when you reintroduced garlic, onions, and wheat, you're likely intolerant to fructans. You'll need to avoid foods high in fructans to help keep your symptoms under control.

However, it's important to note that you should re-challenge the FODMAPs you're sensitive to every 3–12 months, as FODMAP tolerance can change over time. 

Working through the low-FODMAP diet with a dietitian is typically recommended, as it's very restrictive and can lead to nutrient deficiencies if not properly planned. One nutrient of particular concern is fiber. Many of the high-FODMAP foods eliminated on this diet are high in prebiotic fiber. Prebiotics feed your good gut microbes, so eliminating them long-term could lead to negative changes to your gut microbiome.

And one final note. The low-FODMAP diet isn't appropriate for everyone. Those with or at risk for disordered eating, people at risk for malnutrition, children, and the elderly are typically poor candidates for such a restrictive diet. In these cases, other management strategies should be explored. For example, using an enzyme supplement like FODZYME can help digest the FODMAPs that your body can't digest on its own.

High FODMAP foods to avoid

Here's a breakdown of high-FODMAP foods by type of FODMAP. Keep in mind that this list is not exhaustive. To learn more about which foods are high in FODMAPs, consider using the Monash or FODMAP Friendly apps.

Fructans:

  • Garlic
  • Onions
  • Leeks (white bulb only)
  • Asparagus
  • Watermelon
  • Artichokes
  • Brussels sprouts
  • Beets
  • Wheat
  • Rye
  • Barley
  • Pistachios
  • Cashews
  • Inulin (often added to processed foods to boost the fiber content)
  • Oat milk
  • Chamomile tea
  • Oolong tea
  • Herbal tea containing chicory root

Excess Fructose:

  • Apples
  • Pears
  • Mangoes
  • Watermelon
  • Asparagus
  • Artichokes
  • Bell peppers (red, yellow, and orange)
  • Broccoli (stalks only)
  • High-fructose corn syrup (found in some processed foods and drinks)
  • Honey
  • Agave syrup
  • Some fruit juices and dried fruits

Galacto-oligosaccharides (GOS):

  • Kidney beans
  • Black beans
  • Fava beans
  • Cashews
  • Pistachios
  • Beets
  • Oat milk
  • Soy milk (made with whole soybeans)

Lactose:

  • Milk
  • Soft cheeses
  • Ice cream
  • Yogurt
  • Cream
  • Sour cream

Mannitol:

  • Cauliflower
  • Mushrooms
  • Celery 
  • Snow peas

Sorbitol:

  • Apples
  • Pears
  • Peaches
  • Plums
  • Blackberries
  • Apricots
  • Nectarines
  • Cherries
  • Avocados
  • Certain sweeteners found in sugar-free foods (such as xylitol and maltitol)

Low FODMAP alternatives

Fortunately, there are plenty of low-FODMAP alternatives that you can include in your diet while eliminating high-FODMAP foods. This list was compiled using the Monash FODMAP app in October 2024. Since foods often get re-tested, it's important to check the app for the most up-to-date information.

Fruits:

  • Banana (under-ripe)
  • Strawberries (5 berries)
  • Blueberries
  • Raspberries (⅓ cup)
  • Cantaloupe (¾ cup)
  • Dragon fruit
  • Lemon
  • Lime
  • Kiwi fruit
  • Orange
  • Papaya
  • Pineapple (fresh, 1 cup)

Vegetables:

  • Eggplant
  • Green beans
  • Bell pepper (green)
  • Broccoli (heads only)
  • Cabbage (Chinese, red, white)
  • Carrots
  • Collard greens
  • Corn (canned)
  • Cucumber
  • Edamame
  • Lettuce
  • Spring onion (green parts only)
  • Parsnip
  • Potato
  • Sweet potato (½ cup)
  • Spaghetti squash
  • Spinach
  • Tomato (a few slices fresh)
  • Zucchini (⅓ cup)

Dairy and Alternatives:

  • Lactose-free products
  • Butter
  • Aged and hard cheeses
  • Some soft cheeses (such as mozzarella and feta)
  • Almond milk
  • Coconut milk
  • Hemp milk
  • Macadamia milk
  • Quinoa milk
  • Rice milk

Proteins:

  • Canned chickpeas (¼ cup)
  • Canned lentils (¼ cup)
  • Tempeh
  • Firm tofu
  • Edamame
  • Meat (beef, lamb, pork)
  • Poultry
  • Fish 
  • Shellfish
  • Eggs

Grains and Starches:

  • 100% spelt sourdough
  • Slow-leavened sourdough 
  • Oats
  • Quinoa
  • Rice
  • Buckwheat
  • Corn flour
  • Teff
  • Millet
  • Gluten-free bread
  • Gluten-free pasta
  • Corn tortilla

Nuts and Seeds:

  • Almonds (up to 10 nuts)
  • Chestnuts (up to 10 nuts)
  • Hazelnuts (up to 10 nuts)
  • Macadamia nuts
  • Peanuts
  • Walnuts
  • Chia seeds
  • Hemp seeds
  • Sunflower seeds
  • Pumpkin seeds

Beverages:

  • Black tea (weak)
  • Chai (weak)
  • Green tea
  • Licorice tea
  • Peppermint tea
  • Rooibos tea
  • White tea

Tips for Living with FODMAP Sensitivity

Living with a FODMAP intolerance can be frustrating, but there are ways to manage it. Here are some tips for traveling, eating out, and grocery shopping on a low-FODMAP diet.

Traveling while on a low FODMAP diet

No one wants to get caught out when traveling, so bringing your own low-FODMAP snacks can be helpful. Try packing low-FODMAP protein bars, cheese and low-FODMAP crackers, or low-FODMAP fruits like unripe bananas and blueberries.

Eating out on a low FODMAP diet

One of the best things you can do when eating out on a low FODMAP diet is to plan ahead. Research menus before you attend events so you know what's available. It's also important to explain your food sensitivities clearly when ordering. Let the servers know you're avoiding certain ingredients, like onions and garlic.

Another way to make eating out less stressful is to choose simple dishes. Grilled proteins, salads without dressing, and steamed or roasted vegetables are often safer choices. Avoid sauces, dressings, and marinades, which may contain garlic, onions, or sweeteners like high fructose corn syrup.

Consider dining at restaurants whose menus naturally contain more low-FODMAP foods. Japanese, Thai, and Vietnamese restaurants often have plain rice and grilled protein options. If available, choose rice instead of wheat-based items.

Finally, consider eating low-FODMAP for the rest of your meals the day you plan to eat out. This can help minimize the risk of FODMAP stacking if you accidentally eat a FODMAP-containing meal while you're out.

Meal planning and grocery shopping

While grocery shopping on the low-FODMAP diet can feel like you're lost in a maze, it doesn't have to. When meal planning for the low-FODMAP diet, follow the same principles as regular meal planning. That means including a low-FODMAP protein source (like meat, poultry, or certain legumes), a low-FODMAP grain or starch (such as rice or quinoa), and some low-FODMAP vegetables (like cucumber, carrots, or zucchini). 

Check ingredient labels at the grocery store for hidden high-FODMAP ingredients like high fructose corn syrup, inulin, chicory root, garlic, and onion. 

Finally, stock up on essentials like gluten-free pasta, lactose-free dairy, and FODMAP-friendly condiments and spices to make cooking easier. Many brands now offer low-FODMAP-certified products, making navigating the grocery store much simpler.

How Enzymes Can Help with FODMAP Digestion

Remember that FODMAPs aren't digested because the human body lacks the enzymes needed to do so? That's where digestive enzymes come in. Here are some of the enzymes required to break down FODMAPs:

  • Fructan hydrolase (breaks down the fructans found in wheat, onions, and garlic).
  • Lactase (breaks down the lactose found in dairy products). Some people do make enough of the lactase enzyme to break down lactose, but many adults do not produce enough of it.
  • Alpha-galactosidase (breaks down the GOS found in legumes, nuts, and some cruciferous vegetables).

By supplementing with these enzymes, many people find that the FODMAPs that used to bother them suddenly no longer cause digestive issues. 

FODMAP Digestive Support with FODZYME

FODZYME is an enzyme supplement that contains three key enzymes – fructan hydrolase, lactase, and alpha-galactosidase. By providing the enzymes the human body lacks, FODZYME helps digest FODMAPs before they reach the large intestine and cause issues. It's a practical solution for people who find the low-FODMAP diet too restrictive or difficult to follow.

Explore FODZYME and its benefits here.

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