FODMAP diet: what is it, what is it for and how is it done?

The FODMAP diet consists of reducing short-chain carbohydrates and fermentable polyols, a type of alcohol, for a short period of time in subjects with specific affectations. This diet has been found effective for patients with intestinal disorders such as irritable bowel syndrome.

The process will consist of eliminating all the foods rich in the aforementioned components, which are a long list among which we find fruits, vegetables or cereals, to later introduce them little by little to know which ones are the ones that cause damage and we must eliminate .

This process consists of different phases and has to be carried out under the recommendation and medical supervision since the loss of nutrients due to the elimination of a large amount of food is high and if it is not done properly and is maintained indefinitely over time it can damage the gut microbiota. In this article You will know what the FODMAP diet is, what foods should be avoided and which ones can be consumed, what it is for and how the process should be carried out.

What is a low FODMAP diet?

As we can appreciate, FODMAP is an acronym that comes from Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols, the name of this diet had its origin in the University of Musha in Australia.

The components referred to are different carbohydrates that show short chain and polyols, which in neither case are completely digested in the small intestine, causing them to reach the colon. In this way, when they reach the large intestine, they are deposited and are food for the intestinal microbiota, which is a group of bacteria found in the intestine.

The action carried out by these bacteria will produce fermentation and release of gases that cause stomach or intestinal symptoms such as abdominal pain, stomach bloating, diarrhea or constipation and the aforementioned gases. Thus, this diet will consist of avoiding all foods that have the components, short-chain carbohydrates and polyols, mentioned above, in order to avoid discomfort in the subject or unpleasant symptoms. It is for this reason that it will also be known as a low-FODMAP diet..

What foods should we avoid?

Once we know which components are those that are not well digested in the intestine, we must know where these components are to be able to avoid those foods. Thus, We will mainly find them in sugars, starches and fiber, which, as we have already pointed out, are components of food that are not well absorbed in the small intestine, cause water absorption and end up fermenting in the colon.

It has been proven that the foods that contain these carbohydrates are different, within the fermentable ones would be the foods that contain fructans that would be, for example, onion, garlic, wheat and leek and in reference to monosaccharides they are a type of sugars such as galactose that we find in legumes and fructose that make up fruits and honey.

Disaccharides are the union of two monosaccharides, such as glucose plus fructose that gives rise to sucrose, which is found in sugar cane, and glucose plus lactase that produce lactose, which is the sugar found in milk; the galacto-oligosaccharides that they are prebiotic fibers that are not digested and end up fermenting in the colonThese are part of foods such as dairy products, nuts, some seeds, soybeans and legumes, and fructooligosaccharides are found in foods of plant origin, such as watermelon, artichokes and broccoli.

Finally, the polyol that, as its termination indicates, is a type of alcohol, in this case sweet, can be found in cereals, in avocados, in some fruits that have seeds, such as pears, plums or apples. In this way, we see that monosaccharides are sugars that if you combine them together give rise to disaccharides and these in turn can form oligosaccharides or polysaccharides, which in these cases change their characteristics and give rise to starches and fibers.

After naming all the foods that contain these components, let's go on to mention some of those that we can eat to make this diet easier. Yes, you can consume cereals such as rice, oats, quinoa or corn; fruits such as mandarin, kiwi or banana; vegetables or greens such as pumpkin, spinach or carrot; fish of all kinds, raw meat and eggs; dairy products that do not contain lactose such as aged cheeses and vegetable drinks and dried fruits such as peanuts and walnuts.

A point that is considered necessary to make is in reference to the differences between this type of diet and the gluten-free diet. These two procedures are not the same and are not directed to the same people in the case of the gluten-free diet that consists of eliminating foods with wheat, barley and rye, it is recommended to patients with a diagnosis of celiac disease, performing this diet in a indefinite throughout life, since it has been seen that serious risks such as tumors in the digestive system can appear.

On the other hand, as we already know, the low-FODMAP diet is mainly indicated for subjects with irritable bowel syndrome, taking place during a specific and limited period since the food restriction is higher.

What is the FODMAP diet for?

It has been seen that foods that contain FODMAP are not bad and for the majority of the population they are beneficial as they help increase healthy bacteria in the intestine. It is for this reason that before starting this diet you should consult a doctor or a nutritionist to evaluate your condition.

Thus, even if there are some of the symptoms already mentioned, such as a swollen abdomen, diarrhea or some other type of stomach pain, the solution will not always be to reduce carbohydrates, before we must assess if there is a pathology that generates them and what it is.

The pathologies that have obtained good results in different investigations using this diet are irritable bowel syndrome or diseases with intestinal inflammation such as ulcerative colitis or Crohn's disease.. The first being irritable bowel syndrome, the one with the most studies. In these patients it has been observed that the diet rich in FODMAP is not well absorbed in the small intestine, producing an excess of water and gas that will eventually produce the typical symptoms of this syndrome such as diarrhea or abdominal pain and bloating.

Despite the benefit that this diet generates in some cases, as we have always said, we must do it on medical advice, since with it we eliminate a large amount of foods that are rich in nutrients, for this reason a control must be carried out so that the subject continues to have an adequate diet.

How will this diet be carried out?

It will be very important, so that there are no adverse effects, that this diet is carried out in an adequate and controlled way. Its purpose is not to eliminate foods rich in FODMAP, but to see which ones produce negative consequences or symptoms in patients with irritable bowel syndrome.

So that, this diet consists of three steps. The first, obviously, consists of eliminating the aforementioned foods that contain FODMAP, this phase will last between 6 to 8 weeks although it is noted that after 2-3 weeks it can be seen if there is improvement in any symptoms. If after the set time we see that the patient remains the same, we must end the diet and propose another treatment, such as a change in lifestyle or try some medication. If improvement is observed, we will proceed to phase two.

The second procedure, also called reintroduction, consists of re-introducing the foods that we had eliminated in the previous phase, this incorporation will be done progressively and in small quantities, we will begin to make the introduction by food groups, that is, as We saw earlier that they were divided each according to what they were made of. In this way we can observe what reactions they produce and what are the foods that really affect each patient, since they will not be the same for all.

Finally, the last phase It will consist of personalizing the diet to each subject, once we have observed which are the specific foods that generate symptoms, they will be the only ones we eliminate trying to ensure that the amount of food that stops consuming is the minimum, since a large part of these are rich in nutrients such as fruits and vegetables and they are essential for our intestinal microbiota to be strong and healthy.

In this way, as we mentioned before, it will be essential that this diet is controlled by a doctor or a nutritionist, who monitors that the subject continues to consume the necessary nutrients, that it is carried out for a short period of time and only those subjects who present some type of intestinal alteration, since it has been seen that if it is not done properly, there may be a lack of nutrients such as vitamins, iron and calcium, generating long-term adverse effects on the microbiota, reducing the number of healthy bacteria .

In the same way, although it has been observed that in the aforementioned patients with irritable bowel it can benefit them, these effects of reducing symptoms have only been studied for periods of 6 months, that is, no reliable data or results in longer-term follow-up.