FODMAPs are short chain carbohydrates (oligosaccharides), disaccharides, monosaccharides and related alcohols that are poorly absorbed in the small intestine. These include short chain (oligo-) saccharide polymers of fructose (fructans) and galactose (galactans), disaccharides (lactose), monosaccharides (fructose), and sugar alcohols (polyols) such as sorbitol, mannitol, xylitol and maltitol.
The term FODMAP is an acronym, deriving from "Fermentable, Oligo-, Di-, Mono-saccharides And Polyols." These carbohydrates are commonly found in the modern western diet. The restriction of these FODMAPs from the diet has been found to have a beneficial effect for sufferers of irritable bowel syndrome and other functional gastrointestinal disorders (FGID). The low FODMAP diet was developed at Monash University in Melbourne by Peter Gibson and Susan Shepherd. Since the development the diet has been studied for its efficacy for individuals with FGID and is now considered beneficial to be commonly recommended for individuals with FGID.
- 1 Pathophysiology of FGID
- 2 FODMAP absorption
- 3 FODMAP sources in the diet
- 4 Low-FODMAP diet suggested foods
- 5 Nutritional adequacy of a low-FODMAP diet
- 6 Other diets used to treat IBS and FGID
- 7 See also
- 8 References
- 9 External links
Pathophysiology of FGID
The basis of many FGIDs is distension of the intestinal lumen. Such luminal distension may induce pain, a sensation of bloating, abdominal distension and motility disorders. Therapeutic approaches seek to reduce factors that lead to distension, particularly of the distal small and proximal large intestine. Food substances that can induce distension are those that are poorly absorbed in the proximal small intestine, osmotically active, and fermented by intestinal bacteria with hydrogen (as opposed to methane) production. The small molecule FODMAPs exhibit these characteristics.
Poor absorption of most FODMAP carbohydrates is common to everyone. Any FODMAPs that are not absorbed in the small intestine pass into the large intestine, where bacteria ferment them. The resultant production of gas potentially results in bloating and flatulence. Most individuals do not suffer significant symptoms but some may suffer the symptoms of IBS. Restriction of FODMAP intake in the latter group has been found to result in improvement of symptoms.
Fructose malabsorption and lactose intolerance may produce IBS symptoms through the same mechanism but, unlike with other FODMAPs, poor absorption is found only in a minority of people. Many who benefit from a low FODMAP diet need not restrict fructose or lactose. It is possible to identify these two conditions with hydrogen and methane breath testing and thus eliminate the necessity for dietary compliance if possible.
FODMAP sources in the diet
The significance of sources of FODMAPs varies through differences in dietary groups such as geography, ethnicity and other factors.
Fructans, Galactans and Polyols (mandatory restriction)
Sources of fructans
Sources of fructans include wheat (though spelt contains comparatively low amounts), rye, barley, onion, garlic, Jerusalem and globe artichoke, asparagus, beetroot, chicory, dandelion leaves, leek, radicchio, the white part of spring onion, broccoli, brussels sprouts, cabbage, fennel, chocolate and prebiotics such as fructooligosaccharides (FOS), oligofructose and inulin.
Sources of galactans
Sources of polyols
Polyols are found naturally in some fruit (particularly stone fruits), including apples, apricots, avocados, blackberries, cherries, lychees, nectarines, peaches, pears, plums, prunes, watermelon and some vegetables, including cauliflower, mushrooms and mange-tout peas. They are also used as bulk sweeteners and include isomalt, maltitol, mannitol, sorbitol and xylitol.
Fructose and lactose (discretionary restriction)
Sources of fructose
Sources of lactose
When considering a diet that involves avoiding a long list of foods, it is beneficial to look at foods that are acceptable on the diet. Below are low-FODMAP foods typically tolerated categorized by food group.
Vegetables: bamboo shoots, bell peppers, bok choy, cucumbers, carrots, celery, corn, eggplant (aubergine), lettuce, leafy greens, pumpkin, potatoes, squash (butternut, winter), yams, tomatoes, zucchini (courgette)
Fruits: bananas, berries, cantaloupe, grapes, grapefruit, honeydew, kiwi, kumquat, lemon, lime, mandarin, orange, passion fruit, pineapple, rhubarb, tangerine
Protein: beef, chicken, canned tuna, eggs, egg whites, fish, lamb, pork, shellfish, turkey, cold cuts (all prepared without added FODMAP containing foods), nuts, nut butters, seeds
Dairy and non-dairy alternatives: lactose-free dairy, small amounts of: cream cheese, half and half, hard cheeses (cheddar, colby, parmesan, swiss), mozzarella, sherbet, almond milk, rice milk, rice milk ice cream
Grains: wheat-free grains/wheat-free flours (gluten-free grains are free of wheat, barley and rye): bagels, breads, hot/cold cereals (corn flakes, cream of rice, grits, oats, etc.), crackers, noodles, pastas, quinoa, pancakes, pretzels, rice, tapioca, tortillas, waffles
Beverage options: water, coffee and tea (individuals with IBS may also want to limit caffeine), low FODMAP fruit/vegetable juices (limit to ½ cup at a time)
Nutritional adequacy of a low-FODMAP diet
Although there is an extensive list of restrictions to the diet, it can be adhered to for a sustained period with good nutrition maintained. Though many fruits and vegetables must be restricted, many others are suitable for the diet. Wheat-free options are now widely available due to the increase in availability of gluten-free diet alternatives; this makes consumption of adequate carbohydrates and other nutrients more easily attainable. Dietary concerns may arise when individuals dislike the low-FODMAPs alternatives. With so many food restrictions a registered dietitian’s assistance is recommended to help with adherence to the diet and prevent nutritional deficiency. There is also concern with potential gastrointestinal microbiota changes.
Other diets used to treat IBS and FGID
- "FODMAPs". King's College, London. Diabetes & Nutritional Sciences, Research Projects. Retrieved 18 March 2012.
- Gibson, PR; Peter R Gibson and Susan J Shepherd (2010). "Evidence-based dietary management of functional gastrointestinal symptoms: The FODMAP approach". Journal of Gastroenterology and Hepatology 25 (2): 252–258. doi:10.1111/j.1440-1746.2009.06149.x. PMID 20136989.
- Gibson PR, Shepherd SJ (2010). "Evidence-based dietary management of functional gastrointestinal symptoms: The FODMAP approach". Journal of Gastroenterology and Hepatology 25 (10): 252–258. doi:10.1111/j.1440-1746.2009.06149.x.PMID 20136989.
- Reducing fermentable carbohydrates the low FODMAP way. London: Department of Gastroenterology and Department of Nutrition & Dietetics, Guy's and St Thomas' NHS Foundation Trust, and Nutritional Sciences Division, King's College, London. 2011. pp. 2–5 (sample pages).
- "Frequently asked questions in the area of diet and IBS". Med.monash.edu. 2013-08-30. Retrieved 2014-05-26.
- "Low FODMAP Diet". Shepherd Works. Retrieved 2013-07-08.
- "The Monash University Low FODMAP diet". Med.monash.edu. 2012-12-18. Retrieved 2014-05-26.
- Tuck CJ1, Muir JG, Barrett JS, Gibson PR. Expert Rev Gastroenterol Hepatol. "Fermentable oligosaccharides, disaccharides, monosaccharides and polyols: role in irritable bowel syndrome." 2014 May 15:1–16.
- Description of Monash University Low FODMAP diet and lists of available resources
- Stanford University: The Low FODMAP Diet
- Breathtaking diet offers hope for those who can’t stomach fructose, July 8, 2012, Natalie Craig, The Age.
- FODMAP: The FODMAP Friendly Certification Program and other FODMAP Resources, News & Information
- Low FODMAP Recipes, book published by Penguin Australia