A Dietitian’s Take on Low-FODMAP Diets
Summaya Ali, MS, RD
Discussing the low-FODMAP diet always brings back a fond memory. When I was completing an inpatient rotation in the GI Diseases and Surgery Department, I had to visit a patient for diet instruction. I walked in, and the patient and about twelve family members were sitting in a round-table fashion with cups of coffee. It did not seem like a hospital room anymore; it was more like a family get-together. I talked to everyone about low FODMAPs, and they set an example of a powerful support system. It was great! It’s a memory I will value for the rest of my life.
FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols. In simple terms, these are sugars found in our daily foods, and they do not break down completely. In individuals with irritable bowel syndrome (IBS), they can lead to disturbances like pain, gas, bloating, constipation, and diarrhea. IBS is related to a hypersensitive gut. It does not have any gross pathology, meaning the disease cannot be detected in a blood test or seen in imaging studies. The gut is closely connected to our brain through nerves and hormones. Any time this connection is disturbed due to certain foods, lack of sleep, environment, or stress, symptoms will be triggered.
The low-FODMAP diet is an approach to relieving symptoms of a sensitive gut. The diet involves eliminating and reintroducing certain foods for a few weeks to identify which ones provoke symptoms. It helps keep symptoms under control and provides a chance to heal through food. This diet is intended for people with IBS or those experiencing symptoms of a sensitive gut in the setting of other diseases. Elite athletes also use it for exercise-induced gut sensitivity. It is not suitable for the general healthy population, as it is restrictive and can cause nutritional deficiencies. Those with malnutrition or an active eating disorder should not follow this diet. A modified “gentle” version can be used by children, the elderly, and pregnant women with symptoms.
I always begin by reminding patients that this is not intended to be a lifelong diet. It is only followed for a few weeks to identify which foods provoke symptoms. This is different for each person, and the idea is to find out which foods safely work for you. Here are the foods involved:
|High FODMAP||Low FODMAP|
|Fruits||Ripe bananas, apples, pears, peaches, plums, watermelons, cherries, apricots, mangoes, avocados, dried fruit||Unripe bananas, blueberries, cantaloupes, grapefruits, grapes, honeydew melons, kiwis, citrus, papayas, pineapples, strawberries|
|Vegetables||Asparagus, beets, cruciferous vegetables (broccoli, cauliflower, Brussels sprouts, cabbage), garlic, onions, bell peppers, mushrooms, corn, okra, tomato paste, fennel||Carrots, cucumbers, eggplants, green beans, green leafy vegetables, pumpkins, squash, sweet and white potatoes, zucchini|
|Dairy||Lactose in cow’s milk, pudding, ice cream, cottage cheese||Lactose-free milk, plant-based milk, yogurt, hard cheese, cream cheese|
|Grains and cereals||Wheat, barley, rye||Corn, oats, rice, quinoa, sourdough bread|
|Beans and nuts||Soy products (soy milk, tofu), beans, chickpeas, hummus, bean soups, pistachios, cashews||Pumpkin or sunflower seeds, walnuts, peanuts, nut butters|
|Beverages||Carbonated drinks, fruit juice, instant coffee, herbal teas||Black or green tea, peppermint tea|
|Sweeteners and other||High-fructose corn syrup, honey, agave, molasses, sugar alcohols (sorbitol, mannitol, xylitol, maltitol)||Table sugar, brown sugar, maple syrup, rice syrup, stevia, monk fruit, dark chocolate|
Use the list above to circle all the high-FODMAP foods you eat. Replace them with low-FODMAP foods.
Reintroduce one high-FODMAP group at a time, and increase the amount over three days. Then go back to your low-FODMAP diet for the following three days. This is a washout period; it helps to affirm your tolerance of different FODMAPs. Repeat this process for six weeks. It is helpful to keep a written record of symptoms to monitor tolerance.
Now that you know which FODMAPs you tolerate well, you can keep these in your diet. Restrict only the FODMAPs that caused trouble.
The majority of patients have success with the low-FODMAP diet. However, 25% of people will not respond to it. These people should stop the diet and discuss other options with their physician or dietitian, as there could be another underlying issue that needs attention.
Gluten is naturally found in barley, rye, and wheat. Those on a low-FODMAP diet should limit their barley, rye, and wheat intake, as these are known to cause symptoms. However, following a strict gluten-free diet is not necessary. Small amounts of these grains, such as multigrain crackers, soy sauce, or flavored rice, are generally handled well. It becomes a problem when the main ingredient is wheat, barley, or rye. In these cases, it is helpful to utilize gluten-free products.
Many things come into play, including the ripening conditions for produce, canning, boiling, straining, and processing. A good example is bananas. Their FODMAP content is lower when they are slightly unripe. However, when they are left to ripen in cold storage, as in supermarkets, they increase their fructan content to protect themselves from the cold temperature. This helps prevent spoilage but is not helpful for people with IBS.
Products such as refried beans, cooked chickpeas that are used to make hummus, or bean soups that use the water they are cooked in will have a higher FODMAP content. Beans that are canned or raw beans that are boiled and then drained are better choices because the FODMAPs they leach into the liquid can be strained and rinsed off. Products made from soy protein are lower in FODMAPs than soybeans because soy protein is made from defatted soybeans that have been washed to remove sugars and fiber. All of these strategies lower the FODMAP content, but it is still imperative to pay attention to serving sizes to avoid symptoms.
The FODMAP bucket concept helps explain why some foods are better tolerated on different days. Our meals consist of mixed foods, and our lives consist of new happenings. Sleep changes, changes in stress, taking a new medication or antibiotics, dietary changes, travel, and new surroundings all affect the way the gut responds to FODMAPs. Many of these things manipulate the bacteria living inside us, which can bring on different symptoms.
Not necessarily. The low-FODMAP diet still allows for food variety, so there is a low risk for nutrient deficiency. However, some patients may develop deficiencies for other reasons. It is important to have regular medical visits to monitor for deficiencies, and if they do exist, supplements can be used to correct them.
Prebiotics feed the healthy bacteria in our digestive tract and help them thrive. Since prebiotics pass through the system undigested, they trigger gas and bloating in those with IBS. The good news is that the low-FODMAP diet is only for the short term. Fruits and vegetables, grains, and nuts are all good sources of prebiotics. Once you identify which foods in those groups provoke symptoms, you can restrict them.
Probiotics, on the other hand, are essentially the good bacteria our body needs. They are especially important as an imbalance of gut bacteria can cause or worsen IBS and other gut disorders. These good bacteria are found in yogurts and fermented products. Plant-based yogurts are also a good option: look for ones with live and active cultures on the label. There are also probiotic supplements available in the form of capsules or powders that can be mixed in food.
A flare-up is when your intestines go into panic mode. Symptoms will be at their worst, and you will likely become sensitive to things that do not normally bother you. I advise patients to follow these three steps to help them cool down when flare-ups hit:
Water or warm peppermint tea has a calming effect. Flare-ups usually involve episodes of diarrhea or constipation, and hydration can help with both.
Fat tends to make flare-ups worse. Reduce your fat intake—even healthy fats such as those in nuts, seeds, and oils—until symptoms resolve.
If the weather allows, go outdoors. Take deep breaths, and focus on your breathing. When your mind wanders, bring your focus back to your breathing.
The goal of the low-FODMAP diet is to communicate with your body to see what it can handle and when. Sometimes people tolerate certain foods better in the morning, but this could vary by day. Other people have to eat based on their emotions. Managing IBS can be demanding, and I tell patients that some days will be better than others. That’s completely normal. When food, emotions, and lifestyle habits are connected in a healthy way, it becomes easier to find a comfortable balance and keep IBS under control.
Summaya Ali holds a master’s degree in nutrition from the University of Illinois and is a registered dietitian. She is a regular contributor to Halal Consumer© Magazine. She works with a variety of conditions, and two of her favorite areas of practice are chronic kidney disease and cardiovascular disease.