The FODMAP diet is a diet that includes less of certain unabsorbable carbohydrates than most diets. The name of diet is an acronym of Fermentable Oligo-, Di-, Mono-saccharides And Polyols. All of these are carbohydrates that cannot be absorbed properly and that end up in the large intestine, where bacteria use them to generate energy through fermentation.

The purpose of the FODMAP diet is to limit the intake of foods that are the most likely causes of stomach issues. If you are prone to stomach issues, you should not automatically quit eating all cereals and dairy products, as this will place very strict limitations on your diet. The FODMAP diet is proven to help with the symptoms of irritable bowel syndrome.

The article is based on an interview with nutritionist Petteri Lindblad.

FODMAP diet – for whom and when?

FODMAP can provide a solution if you feel that your stomach issues place certain restrictions on your life. People with sensitive stomachs are often sensitive to the fermentation of carbohydrates in the body. The fermentation process generates gases, such as carbon dioxide, and water enters the intestinal system, causing an unpleasant sensation. In addition, the bowel movement of a person with a sensitive stomach may be abnormally frequent, which may increase the feeling of pain and unpleasantness.

When should the FODMAP diet be adopted?

The FODMAP diet should be tested for 4–6 weeks. If the symptoms do not seem to subside in this time frame, the cause of the stomach issues should be studied by a doctor. In the case of acute stomach pain or other inexplicable stomach issues, you should also visit a doctor.
It may not be necessary to observe the FODMAP diet for the rest of your life. The idea of the diet is to calm the irritated stomach and to slowly re-introduce the restricted food products back into your diet.

When should I visit a nutritionist?

You can test a partial FODMAP diet without consulting a nutritionist, but, as in the case of all special diets, you need to know what you are doing. Otherwise, it is possible to experience the symptoms of various deficiencies. For example, dairy products are the primary source of iodine for people in Finland, and removing dairy products from your diet altogether can increase the risk of iodine deficiency. Likewise, you should not diagnose yourself with coeliac disease. The stomach issues of several people are more likely caused by unabsorbable carbohydrates than gluten.

In order to plan a diet that is sure to be safe, a nutritionist should be consulted. Nutritionists can also provide you with tips on how certain foods not allowed in the diet can be replaced. This helps establish a more varied and enjoyable diet than one that simply leaves out certain foods.

Can stress cause stomach issues?

In addition to an inappropriate diet, stress and tiredness can also cause a variety of stomach issues. Because of this, a comprehensive evaluation of your lifestyle is in order. Stress can cause symptoms that resemble a temporary lactose intolerance that will subside when your life becomes more balanced. Likewise, if you experience stomach issues, you should also pay attention to getting enough sleep. Your stomach will benefit from regular sleeping and eating rhythms. Jet lag, night shifts and excessively large meals can make the stomach issues worse. Nutritionists can also help you with regular eating, proper meal sizes and a healthy relationship with food.

FODMAP diet – what to avoid and replace

• Avoid cereals that contain fructans, i.e. rye, barley and wheat. Replace them with oat, quinoa, rice, corn, buckwheat, millet and, if possible, spelt. Eat oat bread instead of rye bread.
• Avoid onions, artichokes, asparagus, beetroots, mushrooms and garlic. Replace them with tomato, cucumber, carrot, lettuce, rutabaga, potato and turnip. A lot of meals contain onion, so remember to check the list of ingredients of processed foods and ask the waiter if a food contains onion.
• Avoid dairy products, muesli and muesli bars that contain oligofructose and inulin.
• Avoid peas, beans, lentils, cabbages and textured vegetable protein (soybean meat). Broccoli, kale and brussels sprouts are allowed in reasonable quantities.
• Avoid apples, pears, apple and pear juice, mangos, watermelon, honey, plums, cherries, peaches and dried fruits. Replace them with citrus fruits, kiwis, bananas, grapes, passion fruit, raspberries, blueberries and strawberries.
• Do not eat or drink lots of ice cream or milk. An occasional glass of milk can be ok, and lactose-free milk does not usually cause issues. Fermented milk products such as yoghurt, viili (sour whole milk) and buttermilk as well as matured cheeses are also recommended. Oat drinks are a good alternative to milk.
• Avoid cashew and pistachio nuts and large amounts of hazelnuts and almonds. Replace them with other nuts and seeds.
• Avoid bubblegum, sugar-free pastilles and protein bars. Protein bars that are low in carbohydrates usually contain sugar alcohols, such as maltitol and xylitol, so it is important to study the list of ingredients of protein bars carefully.
• Alcohol may make stomach issues worse. You should at least enjoy alcohol in moderation.
• The sugar, carbonic acid and caffeine in sodas and energy drinks can make the symptoms worse. Black and green tea are not known to cause issues, but they should not be sweetened with honey.
• Reasonable amounts of coffee are generally ok, but this depends on the individual and needs to be tested.

Expert: nutritionist Petteri Lindblad.

Learn more about irritable bowel syndrome and other chronic intestinal issues:

Stomach pain – what can be the cause? How can it be examined?
Irritable Bowel Syndrome (IBS)
Chronic inflammatory bowel disease or IBD

Learn more about the importance of diet:

The link between obesity and fertility
Vitamin D
The effect of vitamin B12 on memory

Specialists and locations

Satu Aaltonen
Linda Viitasalo
Soile Ruottinen
FT, THM, Ravitsemusterapeutti
Sirpa Soini
Laillistettu ravitsemusterapeutti