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 its 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 and effectiveness
- 6 See also
- 7 References
- 8 Further reading
- 9 External links
Pathophysiology of FGID
The basis of many functional gastrointestinal disorders (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
- oligosaccharides, including fructans and galacto-oligosaccharides;
- disaccharides, including lactose;
- monosaccharides, including fructose;
- polyols, including sorbitol, xylotol and mannitol.
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
Low-FODMAP diet suggested foods
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, corn, eggplant (aubergine), lettuce, leafy greens, pumpkin, potatoes, squash (butternut, winter), yams, tomatoes, zucchini (courgette)
Fruits: bananas, berries (not blackberries or boysenberries), cantaloupe, grapes, grapefruit, honeydew, kiwifruit, kumquat, lemon, lime, mandarin, orange, passion fruit, pawpaw, pineapple, rhubarb, tangerine, tomatoes
Protein: beef, chicken, canned tuna, eggs, egg whites, fish, lamb, pork, shellfish, turkey, cold cuts (all prepared without added FODMAP containing foods), nuts (not cashews or pistachios), 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 (including gluten-free grains, which are free of wheat, barley and rye) and products made with these (e.g. bagels, breads, crackers, noodles, pancakes, pastas, pretzels, waffles); corn flakes, cream of rice, grits, oats, quinoa, rice, tapioca, corn tortillas.
Beverage options: water, coffee and tea, low FODMAP fruit/vegetable juices (limit to ½ cup at a time)
Nutritional adequacy and effectiveness
There is some evidence that a low FODMAP diet helps treat irritable bowel syndrome, and it is becoming an established treatment method.
In common with other defined diets, the low FODMAP diet can be impractical to follow and risks imposing an undue financial burden and worsening malnutrition. There is no good evidence it is effective in treating inflammatory bowel disease: only two small studies have been done which had a poor design making their result susceptible to bias.
- Shepherd, Sue (20 March 2013). Low FODMAP Recipes. Melbourne Australia: Penguin. ISBN 9780143567561. Retrieved 20 Feb 2015.
- "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.
- Reducing fermentable carbohydrates the low FODMAP way (PDF). 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).
- Bayless; Theodore M. Bayless, Stephen B. Hanauer; Professor Theodore M Bayless (14 May 2014). Advanced Therapy of Inflammatory Bowel Disease: Ulcerative Colitis (Volume 1), 3e. PMPH-USA. pp. 250–. ISBN 978-1-60795-216-9.
- "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.
- [unreliable medical source?]https://stanfordhealthcare.org/content/dam/SHC/for-patients-component/programs-services/clinical-nutrition-services/docs/pdf-lowfodmapdiet.pdf
- Staudacher HM, Irving PM, Lomer MC, Whelan K (April 2014). "Mechanisms and efficacy of dietary FODMAP restriction in IBS". Nat Rev Gastroenterol Hepatol (Review) 11 (4): 256–66. doi:10.1038/nrgastro.2013.259. PMID 24445613.
The approach is gaining widespread acceptance through primary, secondary and tertiary centres as a treatment for IBS.
- Hou JK, Lee D, Lewis J (October 2014). "Diet and inflammatory bowel disease: review of patient-targeted recommendations". Clin. Gastroenterol. Hepatol. (Review) 12 (10): 1592–600. doi:10.1016/j.cgh.2013.09.063. PMID 24107394.
Even less evidence exists for the efficacy of the SCD, FODMAP, or Paleo diets. Furthermore, the practicality of maintaining these interventions over long periods of time is doubtful.
- Hou et al. (p. 1598) write: "At a practical level, adherence to defined diets may result in an unnecessary financial burden or reduction in overall caloric intake in patients who are already at risk for protein-calorie malnutrition".
- Fedewa A, Rao SS (2014). "Dietary fructose intolerance, fructan intolerance and FODMAPs". Current Gastroenterology Reports (Review) 16 (1): 370. doi:10.1007/s11894-013-0370-0. PMC 3934501. PMID 24357350.
- van der Waaij LA, Stevens J (2014). "[The low FODMAP diet as a therapy for irritable bowel syndrome]". Nederlands Tijdschrift Voor Geneeskunde (Review) (in Dutch; Flemish) 158: A7407. PMID 24823855.
- Barrett JS (2013). "Extending our knowledge of fermentable, short-chain carbohydrates for managing gastrointestinal symptoms". Nutrition in Clinical Practice : Official Publication of the American Society for Parenteral and Enteral Nutrition (Review) 28 (3): 300–6. doi:10.1177/0884533613485790. PMID 23614962.
- Description of Monash University Low FODMAP diet and lists of available resources
- Stanford University: The Low FODMAP Diet