The Low FODMAP Diet

Why Choose the Low FODMAP Diet?

IBS affects approximately 10–15% of people worldwide, triggering symptoms such as abdominal pain, bloating, excessive gas, and irregular bowel habits. 1 The low FODMAP diet is a rigorously studied dietary treatment and is supported by randomized controlled trials and meta‑analyses demonstrating its effectiveness over standard dietary advice 2 3

Designed as a short‑term diagnostic tool, the diet helps you identify which fermentable carbohydrates (FODMAPs) trigger your symptoms. By systematically reducing and then reintroducing these carbohydrates, with the guidance of a trained dietitian, you gain valuable insight into your personal food triggers 2 4.

Clinical studies show approximately 50–80% of people with IBS experience significant symptom relief following a low FODMAP diet 5 , with some real‑world and meta‑analytic data suggesting even higher responses during personalized reintroduction phases 3 6

What Are FODMAPs? A Simple Explanation

FODMAPs is an acronym for a group of short-chain carbohydrates that can trigger symptoms like pain, bloating, gas and altered bowels.

Here’s a closer look:

Fermentable
By bacteria in the large bowel
This refers to how certain carbohydrates are broken down—or fermented—by bacteria in your large intestine. This fermentation process produces gas, which can lead to bloating, pain, and discomfort in people with sensitive guts.
Oligosaccharides
Fructans and Galacto-oligosaccharides
Found in foods like wheat, rye, onions, and garlic, oligosaccharides are carbohydrates that aren’t fully absorbed in the small intestine. Instead, they travel to the large intestine where they ferment and can cause IBS symptoms.
Disaccharides
By bacteria in the large bowel
Lactose is the sugar found in milk and other dairy products. People who don’t produce enough of the enzyme lactase struggle to digest lactose, which can lead to gas, cramping, and diarrhoea.
Monosaccharides
Fructose (in excess of glucose)
Fructose is a natural sugar found in fruits, honey, and some sweeteners. When there’s more fructose than glucose in a food, it can be poorly absorbed—leading to fermentation in the gut.
And
(&)
This might seem like a filler word, but it’s part of the acronym that brings all the FODMAP groups together! Each type of carbohydrate plays a unique role in digestive sensitivity.
Polyols
eg. Sorbitol, Mannitol, Maltitol, Xylitol
These are sugar alcohols found naturally in some fruits and vegetables, and often used as artificial sweeteners. Polyols are slowly absorbed in the gut and can cause bloating, gas, and loose stools in sensitive individuals.

How Do FODMAPs Trigger Symptoms?

FODMAPs are specific types of short-chain carbohydrates naturally found in many common foods. They are often poorly absorbed in the small intestine so, they pass into the large bowel where gut bacteria rapidly ferment them and produce gas as a by-product.

FODMAPs also have an osmotic effect, meaning they attract water. This gas and fluid can trigger symptoms such as bloating, pain, and changes in bowel habits. People with IBS often experience visceral hypersensitivity, an increased sensitivity of the gut nerves, which makes them more likely to feel discomfort from these normal digestive processes 7 8

The low FODMAP diet isn’t about cutting foods out forever. It is a structured diet best followed in three distinct phases, under the guidance of a trained dietitian or physician to ensure nutritional adequacy and success 2 9

All high FODMAP foods are restricted for a short period, usually for 2 to 6 weeks to reduce digestive symptoms. This phase is only meant to be temporary and should be guided by a qualified dietitian to ensure nutritional adequacy 10

  • Identify and temporarily limit foods high in FODMAPs.
  • Establish a clear baseline of symptom improvement before moving on to Phase 2.

If adequate symptom improvement is achieved during Phase 1, individual FODMAP groups are reintroduced in a systematic way to identify which specific types trigger symptoms and at what amounts 10 7

  • Monitor and record symptoms
  • Identify tolerance levels for different FODMAP groups
  • Gather personalised data

Once all challenges are completed in Phase 2, a long-term, personalised, balanced diet is developed. Not all FODMAPs trigger symptoms for every individual; the goal is to identify personal triggers, not to avoid all FODMAPs forever. This phase reintroduces as many tolerated foods as possible while avoiding known triggers, supporting both gut comfort and nutritional variety, and improving quality of life 10 7

Working with a dietitian is essential to ensure the process is accurate, effective, and nutritionally balanced.

  • Reintroduce all well-tolerated foods back into your diet.
  • Limit or avoid only the FODMAP groups and portions that trigger symptoms.
  • Maintain good gut health with a diverse, balanced diet.
  • Continue symptom monitoring and adjust as needed over time.
Fodmap green background shapes

Have IBS? Find a FODMAP-trained Dietitian on our App.

With so much information, and misinformation online, it’s easy to get confused about what the low FODMAP diet actually involves. Misunderstandings can lead people to follow the diet incorrectly, avoid foods unnecessarily, or think it’s a one-size-fits-all gut health plan. We’re here to clear up some of the most common myths, explain what the diet is (and isn’t), and help you approach it with accurate, evidence-based guidance.

Q. Can I stay on the low FODMAP diet permanently?

The elimination phase (phase 1) should not be permanent. The low FODMAP diet is a diagnostic tool and is not nutritionally complete long term. Prolonged restriction may increase risk of nutrient deficiencies and negatively impact gut microbiota. The goal is to identify your triggers and reintroduce tolerated foods. Then, in phase 3, under the guidance of a dietitian you can find how to follow a lifelong personalized plan to manage your triggers whilst still achieving nutritional adequacy 5

Q. Is the low FODMAP diet suitable if I don’t have an IBS diagnosis?

The diet is intended for individuals with a confirmed IBS diagnosis. Since symptoms overlap with other conditions, consulting a healthcare professional before starting is essential as restricting FODMAPs may be unnecessary and could limit beneficial foods in your diet 2

Q. Are high FODMAP foods ‘bad’ for you?

No. FODMAPs are not inherently harmful. In fact, FODMAPs can be beneficial to health by feeding the good bacteria in our gut. For people with IBS however, they may also trigger symptoms. The low FODMAP diet is about symptom management, not cutting out “bad” foods 6.

Q. Can I follow the low FODMAP diet without professional support?

It’s best to work with a qualified dietitian or physician who can guide you through the phases safely and ensure you maintain balanced nutrition throughout the process. You can search for FODMAP trained healthcare professionals inside our app 2 10

Q. Is the low FODMAP diet the same as a gluten-free diet?

No. The low FODMAP diet targets specific fermentable carbohydrates, while gluten-free diets eliminate gluten, a protein in wheat and related grains. They serve different purposes, though some foods overlap.

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References

  1. Chey WD, Kurlander J, Eswaran S. Irritable bowel syndrome: a clinical review. JAMA. 2015;313(9):949–58. doi:10.1001/jama.2015.0954
  2. Eswaran S, Dolan RD, Chey WD. The role of diet in the management of irritable bowel syndrome. Am J Gastroenterol. 2017;112(7):1134–42. doi:10.1038/ajg.2017.108
  3. Marsh A, Eslick EM, Eslick GD. Does a diet low in FODMAPs reduce symptoms associated with functional gastrointestinal disorders? A comprehensive systematic review and meta-analysis. Eur J Nutr. 2016;55(3):897–906. doi:10.1007/s00394-015-0892-6
  4. McKenzie YA, Bowyer RK, Leach H, Gulia P, Horobin J, O’Sullivan NA, et al. British Dietetic Association systematic review and evidence-based practice guidelines for the dietary management of irritable bowel syndrome in adults (2016 update). J Hum Nutr Diet. 2016;29(5):549–75. doi:10.1111/jhn.12385
  5. Staudacher HM, Whelan K. The low FODMAP diet: recent advances in understanding its mechanisms and efficacy in IBS. Gut. 2017;66(8):1517–27. doi:10.1136/gutjnl-2017-313750
  6. Halmos EP, Power VA, Shepherd SJ, Gibson PR, Muir JG. A diet low in FODMAPs reduces symptoms of irritable bowel syndrome. Gastroenterology. 2014;146(1):67–75.e5. doi:10.1053/j.gastro.2013.09.046
  7. Barrett JS. How to institute the low FODMAP diet. J Gastroenterol Hepatol. 2017;32(S1):8–10. doi:10.1111/jgh.13686
  8. Monash University. The low FODMAP diet [Internet]. Melbourne: Monash University; c2023 [cited 2025 Aug 25]. Available from: https://www.monashfodmap.com
  9. AboutIBS.org. Low FODMAP diet guidelines [Internet]. Alexandria (VA): International Foundation for Gastrointestinal Disorders; c2023 [cited 2025 Aug 25]. Available from: https://aboutibs.org/treatment/ibs-diet/low-fodmap-diet/
  10. ref:2

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