Health & Fitness

Digestive issues? Try the FODMAP diet

GALACTANS are found in the sugar galactose, which occurs in foods like broccoli, lentils and chickpeas.
GALACTANS are found in the sugar galactose, which occurs in foods like broccoli, lentils and chickpeas. MCT

The gluten-free diet has become the diet du jour over the last several years. While a gluten-free diet is a must for those who have been diagnosed with gluten sensitivity or celiac disease, many other people are opting to go gluten-free as well, saying that the diet helps with their digestive problems, eczema, chronic fatigue, ADHD, autism, depression and more.

But there’s now a new diet in town that’s also being touted for alleviating digestive distress — the FODMAP.

The acronym FODMAP “Fermentable, Oligo-, Di- and Mono-saccharides and Polyols,” is used to describe a group of fermentable short-chain carbohydrates. These carbohydrates are poorly absorbed in the small intestine and quickly fermented by bacteria in the gut. The bacteria then produce gas, which can cause stomach discomfort. FODMAPS can act as sponges to draw in and hold excess fluid in the large intestines. Together with the gas this can also cause bloating, diarrhea or constipation.

FODMAPS are found in everyday foods. Some individuals may tolerate small amounts, but symptoms can develop if they consume quantities that exceed their threshold — and everyone’s threshold is unique.

The FODMAP diet has been found to be helpful for those living with irritable bowel syndrome (IBS), chronic abdominal pain, gas, bloating, diarrhea or constipation. For many, adhering to this diet may greatly help their quality of life.

It begins with an elimination diet lasting 2-6 weeks, where FODMAP foods are completely avoided for a period of time and then are slowly added back in. The low FODMAP is a learning diet rather than a diet that you stay on forever.

This approach helps determine a threshold for the amount of FODMAPs an individual can tolerate at one time. FODMAP foods are divided into categories below:


Lactose is the sugar found in cow, sheep and goat milk. Lactose intolerance is caused by a reduction or absence of the lactase enzyme that breaks down these sugars.


Fructose, which is known as fruit sugar, is found in honey, high-fructose corn syrup, agave, and sucrose (table sugar). Fructose-containing foods with a 1:1 ratio of fructose to glucose are generally well-tolerated on the FODMAP diet. However, foods with excess fructose compared to glucose — such as apples, boysenberries, figs, watermelon, asparagus, artichoke, sugar snap peas, pears and mangoes — can often trigger abdominal symptoms in those with sensitivities.


Fructans are oligosaccharides made of fructose molecule chains that cannot be absorbed. Most people’s fructan intake comes from wheat, barley and rye.


Galactans are the oligosaccharides found in the sugar galactose. Galactans can contribute to gas and GI distress. Dietary sources of galactans include lentils, chickpeas, kidney beans, black-eyed peas, broccoli, cabbage, brussels sprouts and soy-based products.


Polyols are also known as sugar alcohols. They are found naturally in some fruits and vegetables and added as sweeteners to sugar-free gums, mints, cough drops and medications. Sorbitol and xylitol are some of the most common.

Learn more

For a quick reference to high- and low-FODMAP foods refer to the “FODMAPs Checklist” table at

The Low FODMAP diet has two phases. The first phase is where all high FODMAP foods are restricted. This phase generally lasts 2 to 6 weeks. The second phase is where the diet is liberalized to suit each individual’s thresholds.

It can be extremely helpful to work with a registered dietitian to help you design your dietary plan as it can be extremely challenging to establish your body’s thresholds. But once these have been established, this diet can have incredible lifelong results for those with IBS and other gastrointestinal distress. Be sure to consult with your doctor to rule out more serious intestinal conditions.

SeAnne Safaii-Waite, Ph.D., R.D., L.D., is an assistant professor at the University of Idaho Dietetics Program and past president of the Idaho Academy of Nutrition and Dietetics.