The low FODMAP diet: A solution for IBS?

Carbohydrates are the body’s main source of energy. They are composed of carbon, oxygen and hydrogen, and are water-soluble, with the exception of fibre. They differ in size and complexity. 

Interviewed on the subject, Kathryn Adel, M.Sc, Dt.P, CSSD, Registered Dietitian at SOSCuisine.com and a specialist in sports and gastrointestinal nutrition, made a list of the main FODMAPs:

• Fructose: Found in many fruits, honey, agave syrup, molasses or high-fructose corn syrup (added to sweeten various processed foods)
• Lactose: Found in dairy products
• Fructans: Found in many foods, including wheat, rye, barley, garlic, onions, dried fruit and legumes
• Galactans: Found in large amounts in legumes and some soy foods
• Polyols: Sugar alcohols found in some fruits and vegetables and often used as sweeteners

During digestion, simple sugars (glucose and galactose) are absorbed into the bloodstream in the first few segments of the small intestine. Disaccharides (two simple sugars attached together) and other more complex sugars must be converted into simple sugars by digestive enzymes before they can be absorbed.  

This digestive process is extremely efficient, so there is usually very little sugar left after the food has passed through the small intestine.  

However, when sugars are poorly or incompletely digested during this process, they end up in the colon where they are subjected to the actions of the abundant bacteria found there. It is the intestinal flora that is responsible for the fermentation of sugars, and this phenomenon produces a lot of gas. 

In people who are sensitive or suffer from IBS, this gas can cause bloating, abdominal pain and even diarrhea.

Kathryn Adel explains that a low FODMAP diet is usually recommended after a diagnosis of irritable bowel syndrome. Medical expertise is required to rule out more serious conditions such as celiac disease, Crohn’s disease or cancer. 

The low FODMAP diet begins by eliminating FODMAD-rich foods, a process that lasts two to six weeks. “In less than 14 days, we can determine whether the diet is working,” says the dietitian. “The diet will be discontinued if no improvement is seen after two weeks.”

The second phase involves reintroducing specific foods to see which food families cause digestive disorders and at what threshold the symptoms appear. This testing phase allows us to isolate each FODMAPs family and identify those that are poorly digested.

Then, in the third phase, the patient can go back to eating almost as before, avoiding only the problematic foods.

“Usually, not all FODMAPs cause digestive problems. Identifying the most problematic ones and eliminating them are enough to improve the condition of patients,” says the specialist.

The dietitian believes that with professional care, the risks are almost non-existent. “Some people may find the reintroduction process long and difficult, others will experience some symptoms again, but in general, the relief obtained is very motivating.”

There are, however, a few dangers to following this diet without medical advice. “There is a risk of negatively affecting one’s intestinal flora or developing nutritional deficiencies if the diet is continued for too long. Some people are also going to have trouble performing the reintroduction tests themselves.”

Therefore, it is recommended to have a follow-up by a medical professional to maximize the chances of success of a low FODMAP diet. A website such as SOSCuisine.com is also an excellent source of help and information. Among other things, it can provide personalized menus for those following such a diet as well as support from specialized dietitian or self-service by an intelligent assistant to make reintroduction tests easier.