Gut troubles? Consider a low-FODMAP diet for IBS

Sue Heikkinen, MS, RDN, CDCES, BC-ADM, ACE-PT. Sue was trained on the use of a low FODMAP diet for IBS by Monash University

Did you know a low-FODMAP diet for IBS may help you pinpoint which foods trigger disruptive digestive symptoms? Even if you can't pronounce what FODMAP stands for, you'll soon be on the hunt to avoid these ingredients and, hopefully, find some relief.

What is so special about the low-FODMAP diet for IBS?

If you suffer from irritable bowel syndrome (IBS), you are not alone. This challenging digestive condition affects about 10% of the population worldwide. IBS causes abdominal discomfort, sometimes severe, accompanied by constipation, diarrhea, or both.

The cause of IBS is not known, but one theory suggests that IBS sufferers experience more pain with bloating or distention in the gut. Stress, anxiety, and certain dietary factors can set off IBS symptoms, although individual triggers can vary.

“FODMAP” refers to a group of short-chain carbohydrates that can be hard to digest. If you have IBS, high-FODMAP foods may be adding to your woes. FODMAPs can cause trouble when they meet up with gut bacteria that feast on them and produce gas. Some FODMAPs can draw fluid into the gut, leading to bloating and cramping, and possibly diarrhea.

FODMAP stands for:

Fermentable: by the bacteria in our gut
Oligosaccharides: 3-10 sugar units long (fructans and galacto-oligosaccharides)
Disaccharides: 2 sugar units long (lactose)
Monosaccharides: 1 sugar unit (fructose)
And
Polyols: Sugar alcohols (sorbitol, mannitol, and xylitol)

Should I try a low-FODMAP diet for IBS?

While a low-FODMAP diet will not cure IBS, it may bring you welcome symptom relief. A low-FODMAP diet was proven effective for about three out of four people with IBS.

Discuss your condition with your doctor before starting the low-FODMAP diet. Perhaps your doctor diagnosed you with IBS after ruling out celiac disease and other digestive disorders. If so, this diet may be a game-changer for you. Work with a dietitian who has low-FODMAP diet expertise to help you plan meals and ensure you are getting adequate nutrition.

Note: If you have an eating disorder, a low-FODMAP diet may not be appropriate for you. If you have little control over your food choices or have difficulty meeting your nutrition needs, then such a disciplined diet may also be challenging for you.

3 Stages of the low-FODMAP diet

A low-FODMAP diet is not meant to be followed indefinitely. Although it can be tempting to remain on the diet when you feel better, it is important to learn your specific triggers and broaden your diet if possible. Many healthy and gut-protective foods contain FODMAPs.

According to Monash University, the pioneers of low-FODMAP diets, there are 3 distinct stages to a low-FODMAP diet.

1. Low-FODMAP diet

The restriction phase typically lasts 4-6 weeks. The goal is to replace high-FODMAP foods with low-FODMAP alternatives to determine if FODMAPs are a factor in your IBS symptoms.

Here are examples of high- and low-FODMAP foods; it is not a comprehensive list. For more detailed information about the FODMAP content of foods, refer to the Monash University Low FODMAP Diet App.

Food Group: Grains/starches
High FODMAP: wheat, barley, rye
Low FODMAP: rice, quinoa, potato

Food Group: Dairy
High FODMAP: milk, yogurt, soft cheeses
Low FODMAP: hard cheeses, lactose-free milk/yogurt, almond milk

Food Group: Fruits
High FODMAP: apples, peaches, cherries, dried fruit
Low FODMAP: oranges, blueberries, pineapple, kiwi fruit

Food Group: Vegetables
High FODMAP: onion, garlic, artichokes, asparagus, mushrooms, celery
Low FODMAP: spinach, lettuce, cucumber, carrot, green beans

Food Group: Meat/protein foods
High FODMAP: silken tofu, beans, meats seasoned with onion or garlic
Low FODMAP: Plain meats, poultry, fish, eggs, tempeh, firm tofu

Food Group: Nuts and seeds
High FODMAP: cashews, pistachios
Low FODMAP: walnuts, peanuts, sunflower seeds

Food Group: Sweeteners
High FODMAP: honey, agave, high fructose corn syrup, sugar alcohols
Low FODMAP: brown sugar, white sugar, maple syrup

Sample low-FODMAP menu

Breakfast: oatmeal with blueberries, walnuts, brown sugar, and almond milk; scrambled egg
Lunch: soft corn tortillas with cheese, chicken, chopped tomatoes, and lettuce
Dinner: grilled pork chop, baked potato, tossed green salad with olive oil vinaigrette
Snacks: rice crackers with peanut butter; string cheese with a small orange

If you do not notice an improvement during the restriction phase, FODMAPs probably aren’t a factor in your symptoms. If there's a noticeable improvement, you are ready to move on to the reintroduction phase.

2. Reintroduction

In this phase, you will systematically reintroduce foods from each FODMAP category, while keeping the rest of your diet low in FODMAPs. Your dietitian can help you choose the right foods and quantities to reintroduce and assess your symptoms. Typically, you will start with a small portion of the food, increasing the amount over the course of three days. You would then return to your baseline low-FODMAP diet before reintroducing another food.

Some types of FODMAPs might not produce any IBS symptoms, whereas others might make you miserable. You may be able to tolerate a small portion of a food, but not a larger amount. Keep a food log with notes about how well you respond. This will help you move on to the next stage of the diet.

3. Personalization

Once you have learned which foods trigger your symptoms, you then make a plan to monitor your intake. Most people can tolerate small amounts of foods that otherwise cause them symptoms when eaten in greater amounts. MyNetDiary has a Daily Notes section to record your symptoms.

If you avoid certain foods due to FODMAP intolerance, tracking with MyNetDiary will allow you to monitor crucial nutrients such as calcium and fiber.

Don’t give up. IBS symptoms and food tolerance often change over time. Rechallenge foods from time to time to see if they are still problematic. You may be pleasantly surprised that you can expand your intake of high-FODMAP foods.

FODMAPs and weight loss

A low-FODMAP diet is not meant to be a weight-loss plan. However, dieters without IBS may experience unexpected digestive problems if they start eating large amounts of certain high-FODMAP foods. For example, sugar-free gum, candies, and ice creams are often high in sugar alcohols such as sorbitol. The sugar alcohol content will be listed on the Nutrition Facts label. Fiber-fortified foods, such as protein bars, cereals, and protein drinks, often have added FODMAPs in the form of inulin, chicory, or fructooligosaccharides (FOS). These FODMAPs are common triggers of gas and bloating.