Low-FODMAP diet for Irritable Bowel Syndrome
The low-FODMAP diet is used for chronic gastrointestinal complaints. A low-FODMAP diet is recommended in particular if you have Irritable Bowel Syndrome, abbreviated as IBS. In that case, you have chronic gastrointestinal complaints whose cause is unknown. The term FODMAP diet is often used, but in fact it is a low-FODMAP diet in which specific nutrients are omitted. FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols. The meaning of these terms is explained later on this page.
What is Irritable Bowel Syndrome (IBS)?
IBS is a specific pattern of symptoms. In principle, an IBS diagnosis is made on the basis of the following symptoms: cramps, abdominal pain, bloating, gas, diarrhoea or constipation when these symptoms have been present for more than 3 months. The term IBS applies to symptoms that are not associated with a disease. The diagnosis is often made on the basis of the symptoms mentioned above and a special diet is prescribed without an extensive stool test having been carried out.
Diagnosing IBS
For typical IBS symptoms, we recommend having the stool tested to rule out an underlying disease. Research has shown that 30% of people diagnosed with IBS had an underlying organic cause, such as gluten intolerance, colitis or infection with bacteria or intestinal parasites. In some cases, there was a stomach ulcer, an inflamed oesophagus, chronic liver disease, gallstones and, in a number of cases, even bowel cancer or coeliac disease.
Development of the FODMAP diet
Joanne Slavin was the first to describe the use of the low-FODMAP diet in clinical practice in Beyond Belly Pain; 30 people with IBS followed the FODMAP diet for 3 weeks. The findings were compared with those of 8 healthy people. Gibson and Susan Shepherd from Melbourne published the article ‘Fructose malabsorption and symptoms of irritable bowel syndrome: guidelines for effective dietary management’ in 2006. In 2013, ‘The Complete Low-FODMAP Diet: A Revolutionary Plan for Managing IBS and Other Digestive Disorders’ was published under their names.
What does a low-FODMAP diet involve?
The Australian Barrett wrote in the journal Nutrition Clinical Practice that eliminating FODMAPs is accepted as an effective strategy for managing the symptoms of Irritable Bowel Syndrome. This researcher states that both sugars and starch are not absorbed properly in the small intestine and therefore reach the large intestine, where they form gases. In 86% of people with IBS symptoms, this diet is associated with a reduction in bloating, flatulence and abdominal pain. Bowel movements also improve, meaning that people have less diarrhoea or constipation.
What does FODMAP stand for?
In broad terms, the low-FODMAP diet involves avoiding fermented products, all sugars and, to a large extent, starchy foods. These products can cause symptoms through gas formation.
The abbreviation FODMAPs stands for:
- F = Fermentation. Fermented products can cause an increase in intestinal gas.
- O = Oligosaccharides, meaning long chains of sugars, including fibres and the starch in grains.
- D = Disaccharides, sugars containing two molecules, sucrose (table sugar) and lactose (milk sugar).
- M = Monosaccharides, single sugar molecules (glucose or fructose), often added to drinks.
- P = Polyols. Artificial sweeteners.
- The different types of sugars are avoided
The sugars to avoid on a low-FODMAP diet are:
- 1. Mono. Simple sugars. Fruit juices, apples, pears, mangoes, cherries, watermelon and honey are rich in fructose. This is often tolerated.
- 2. Disaccharides. Double sugars such as table sugar and lactose (milk sugar). In many people with gastrointestinal complaints, symptoms decrease when sugar and milk are eliminated.
- 3a. Oligosaccharides are long chains that are present in garlic, leeks, onions, legumes, lentils and chickpeas; it is often better to omit them. This group also includes carrots, Jerusalem artichokes, peaches, watermelon, Brussels sprouts and fennel. These are not prohibited, however.
- 3b. Fructo-oligosaccharides consist of fructose chains and are present in certain vegetables, for example Jerusalem artichokes, which can indeed cause flatulence.
- 4. Polyols are artificially produced sugars such as xylitol, sorbitol, lactitol, isomalt, maltitol and polyglycitol syrup. These sugars contain few calories. Polyols occur naturally in apples, pears, cherries, plums, avocado and mushrooms. When you omit sugar, it may actually be beneficial to use xylitol instead.
- 5. Fermentation. There is a difference between fermented products and fermentation that takes place in the intestine. Sauerkraut and kefir are actually products that contain beneficial bacteria.
Fructose and fructans
Fructose, also called fruit sugar, is a single molecule, just like glucose. Fructans are chains of fructose with a sucrose molecule. Fructans are found in vegetables such as Jerusalem artichokes, artichokes, asparagus, peas, all types of cabbage, leeks, garlic, onions and chicory. People with IBS are said to absorb fructose poorly in the small intestine, causing the fructose level in the large intestine to rise. Gut bacteria ferment fructose, which produces gases. It is therefore recommended to avoid fructans. Wheat also contains more fructans than spelt, which is why spelt bread is recommended.
Advice for a restricted FODMAP diet
| Grains you can eat | Grains you cannot eat |
|---|---|
| Gluten-free and teff-free bread Bread made from spelt flour Gluten-free and teff-free crackers Gluten-free and teff-free croissants Oatmeal Gluten-free and teff-free crispbread Corn cakes ‘cornflakes’ | Wheat bread Rye Multigrain and barley Croissants, ciabatta Focaccia, naan bread Crispbread Muesli made from wheat, multigrain and fruit |
| Buckwheat Cassava (tapioca) Oats – quinoa Maize – polenta Spelt | Barley Rye Wheat Triticale Wheat semolina |
| All types of rice, e.g. Basmati, Pandan, risotto rice White rice – brown rice | Bulgur Couscous Multigrain rice |
| Gluten-free pasta Pure spelt pasta Rice vermicelli | Wheat pasta Gnocchi |
| Potatoes | Sweet potatoes |
You cannot eat:
- Sugar (contains 50% glucose, 50% fructose)
- Sweet potatoes
- Wheat products
- Other grains containing gluten, rye or barley
You can use:
- Spelt, which contains gluten
- Oatmeal
- Rice
- Maize
- Buckwheat
- Potatoes
Grains have a very high starch content:
| Per 100 grams | Starch glucose grams | Protein grams |
|---|---|---|
| Rice cake | 89 | 4 |
| Rice crispies | 88 | 6 |
| Cornflakes | 85 | 8 |
| Cassava flour | 80 | 2 |
| Uncooked rice | 78 | 6 |
| Uncooked oatmeal | 62 | 13 |
| Gluten-free bread | 54 | 6 |
| Sweet potato | 32 | 3 |
| Potato | 22 | 3 |
| Banana | 22 | 1 |
Discussion points about the low-FODMAP diet
Below are a number of comments about the proposed low-FODMAP diet.
- For IBS, the advice is to avoid sugar, and therefore glucose as well. Because grains can still be used, this provides contradictory information. Grains such as wheat, rice and oats and seeds such as buckwheat and quinoa contain a lot of starch. Starch consists entirely of glucose molecules. 100 grams of oatmeal contains 65 grams of starch. Rice cakes recommended in the FODMAP diet have a glucose content of 89%. Gluten-free bread also has a high starch content.
- Bread made from organically grown grains may be better tolerated. Ordinary bread from the bakery and supermarket will often contain flavourings. Grain products may also contain pesticide residues.
- Gluten. It is recommended to use gluten-free products. The low-FODMAP diet therefore also recommends eating gluten-free bread. Wheat, rye and barley are avoided, but spelt is recommended; this is confusing because spelt contains gluten.
- Wheat. It is recommended to avoid wheat. In fact, however, it is mainly people with a wheat allergy who experience symptoms when eating wheat bread. They benefit from eating spelt bread. Another reason for using spelt is that it does not contain fructan.
- Fructans are avoided. Fructans are fructose chains; when they are not digested properly, this is called fructose intolerance or fructose malabsorption. This is a specific syndrome that can be investigated. Fructans are found mainly in vegetables and fruit, and also in wheat.
- Yeast. Omitting bread that contains yeast can quickly lead to an improvement in gastrointestinal complaints, especially in people who are sensitive to yeasts or when the intestine contains yeast or Candida.
- An additional disadvantage of eating bread is the topping. Margarine, cheese and spreads such as nut spread, chocolate spread and jam are not beneficial for the intestinal environment.
- Fermented products. It is advised to avoid fermentable foods. Nielsen studied the effect of fermented sauerkraut containing Lactobacillus. These are bacteria that are beneficial for IBS symptoms. Sourdough bread is often better tolerated than bread made with baker’s yeast. People have eaten sourdough bread for thousands of years. Fermented products are not the same as products that ferment in the intestine. Foods that produce gas can be avoided.
- Finally, we emphasise that a lot of bread and other grain products are eaten in the Netherlands, including at lunch, whereas people in other countries more often eat a hot meal. If you eat grains for breakfast and lunch every day and also eat pasta or pizza in the evening, there is not enough variety. The advice is to omit grains temporarily and follow the rotation diet. You then choose different proteins, fats and vegetables every day.
Conclusion about the FODMAP diet
The low-FODMAP diet contains useful elements, but it is not advisable to start it without first having laboratory tests carried out. It is important to establish a diagnosis first in order to determine whether there is an underlying condition. What can be investigated?
- Gut flora analyses and determination of the numbers of Candida cells
- Parasites: after treatment for parasites, the symptoms will often disappear
- Testing for inflammatory reactions and histamine intolerance
- When gluten is not tolerated well, it is important to investigate whether gluten intolerance can be ruled out. It is not useful to eat gluten-free bread if you do not have coeliac disease; this bread also has a high starch content
For gastrointestinal complaints, the advice is to omit all grains or limit them considerably. Eat plenty of vegetables to promote the growth of beneficial gut bacteria. You can find out which foods cause symptoms by following the elimination and rotation diet.
