This diet is carried out in three phases:
- Elimination phase – is based on the strict elimination of products with a high FODMAP content, usually for 4 to 6 (maximum 8) weeks. During this time, it’s important to observe the occurrence of symptoms and seek a link to specific foods.
- Reintroduction phase – if symptoms are effectively alleviated, a second, less restrictive phase should be initiated depending on the body’s tolerance. Products containing FODMAPs should be gradually reintroduced while observing the symptoms. This phase lasts several weeks or even longer as the reintroduction of products is slow.
- Maintenance/personalisation phase – the aim is to continue the consumption of products that are well tolerated and limit the foods that cause symptoms. Since the tolerance to different FODMAPs may vary over time, patients may try to reintroduce foods that currently trigger symptoms after several months [1, 2].
Such approach minimizes unnecessary dietary restrictions and ensures that the diet is maximally varied while maintaining adequate symptom control [1, 2].
Mechanisms of action of low-FODMAP diet
It’s believed that the main mechanism of action of low-FODMAP diet is the reduction of absorption of osmotically active short-chain carbohydrates in the small intestine, which results in the reduction of water content in the intestine and, consequently, decreased intestinal fermentation and gas production. Recent studies have demonstrated that compared to standard diet, the low-FODMAP diet reduces serum levels of proinflammatory interleukins: IL-6 and IL-8, faecal bacteria (Actinobacteria, Bifidobacterium and Faecalibacterium prausnitzii), short-chain fatty acids (SCFA) and butyric acid .
However, the low-FODMAP diet may cause significant changes in intestinal microbiota. Several studies have reported a change in bacterial profile of patients’ faeces. After 4 weeks of low-FODMAP diet the number of bifidobacteria was significantly reduced in patients with IBS. Moreover, a general decrease in the number of bacteria in the intestinal lumen was observed [1, 3, 5, 6]. For this reason, it’s necessary to be cautious about long-term limitation of FODMAP intake. It’s recommended to limit FODMAP until appropriate symptom control is achieved in patients with IBS. In addition, individuals with no symptoms shouldn’t go on low-FODMAP diet.
In addition, long-term elimination of products high in FODMAPs isn’t recommended due to lack of sufficient data on long-term use of the low-FODMAP diet. It’s likely to lead to nutritional deficiencies and, subsequently, to health consequences (especially when used without the supervision of a dietitian) [1-7].
It has been demonstrated that probiotic supplementation reduces the loss of intestinal microbiota and increases the body tolerance to products high in FODMAPs [6, 7].
Products high in FODMAPs and their low-FODMAP alternatives 
|FODMAP type||High-FODMAP products||Low-FODMAP products|
|Oligosaccharides (fructans / galactooligosaccharides)||Vegetables: artichokes, asparagus, beets, brussels sprouts, broccoli, cabbage, fennel, garlic, leeks, okra, onions, peas, shallots Fruits: watermelon, apple, white peaches, persimmon Wheat and rye when eaten in large amounts (e.g. bread, pasta, couscous, cookies, crackers, biscuits)Legumes: chickpeas, lentils, kidney beans, baked beans, soy beans||Bamboo shoots, bell peppers, bok choy, carrots, celery, chard, chayote, chives, choy sum, corn, eggplant, green beans, lettuce, parsnips, pumpkins, spring onions (green part only), tomatoes; onion and garlic substitutes: garlic-infused oilBananas, blueberries, cantaloupes, carambola, durian, grapefruit, grapes, honeydew melon, kiwi, lemons, limes, mandarin, oranges, passion fruit, pawpaw, raspberries, strawberries, tangelosGluten-free and spelt bread and cereal products Canned chickpeas|
|Disaccharides (lactose)||Milk (cow, goat, sheep), yogurt, soft cheeses, ice cream||Lactose-free milk and yogurt, rice milk, hard cheeses, butter, ice cream substitutes such as gelato and sorbet|
|Monosaccharides (fructose)||Fruits: apples, Asian pears, pears, clingstone peaches, mango, sugar snap peas, watermelon, canned fruit in natural juice; large total fructose dose: concentrated fruit sources; large servings of fruit, dried fruit, fruit juiceHoneySweeteners: fructose, high fructose corn syrup (HFCS)||As listed above Maple syrup, golden syrupSweeteners: any except polyols|
|Polyols||Vegetables: avocados, cauliflower, mushrooms, snow peas, sweet cornFruits: apples, apricots, Asian pears, cherries, longon, lychee, nectarines, peaches, pears, plums, prunes, watermelonSweeteners: isomalt, maltitol, mannitol, sorbitol, xylitol||As listed above As listed above Sucrose, glucose|
FREE MEAL PLAN FOR DOWNLOAD:
Ideal for a woman aged 39 years, 62.9 kg body weight and 172 cm tall, performing hourly strength training 3x a week. In this case the aim is to maintain the current body weight.
The effectiveness of low-FODMAP diet, and thus the alleviation of IBS symptoms, depends on its adherence. It’s difficult to follow such diet on your own, so don’t hesitate to seek our help!
3. Nanayakkara WS, Skidmore PML, O’Brien L, Wilkinson TJ, Gearry RB. Efficacy of the low FODMAP diet for treating irritable bowel syndrome: the evidence to date. Clinical and Experimental Gastroenterology. 2016; 9: 131-142.
6. Rao SSC, Yu S, Fedewa A. Systematic review: dietary fibre and FODMAP-restricted diet in the management of constipation and irritable bowel syndrome. Alimentary Pharmacology and Therapeutics. 2015; 41: 1256-1270.