Wednesday, 14 October 2015

Low FODMAP diet provides both short- and long-term relief of gut symptoms

By Dr Jane Varney

Good news for people following a low FODMAP diet! A recent study conducted by researchers at Kings College London measured the long-term effectiveness of a low FODMAP diet. The study followed 100 participants with IBS from baseline (pre-FODMAP restriction), through the elimination and rechallenge phases and for 1 year thereafter. Participants reported their gastrointestinal symptoms at baseline (before FODMAP restriction), at 4-8 weeks (after FODMAP restriction) and at 1 year (following a rechallenge phase). Dietitians taught participants how to implement the elimination and rechallenge phases, but participants made their own food selections (meals were not provided in this study).

Sixty-two percent of participants reported satisfactory relief of symptoms after the initial elimination phase and the majority of these participants (71%) continued to experience satisfactory symptom relief at 1 year. Almost all of the participants who responded to the diet at 1 year continued to avoid high FODMAP foods at least half of the time.

So what are the take home messages from this study? Reassuringly, the study shows that a low FODMAP diet improves IBS symptoms in both the short, and long-term. The study also suggests that some degree of FODMAP restriction may be necessary to maintain adequate symptom control in the long-term. It is here that we issue a note of caution. Given the adverse changes in gut microbial populations associated with long-term adherence to a low FODMAP diet, we always encourage people to enter a re-challenge phase and under the guidance of a dietitian, find an acceptable balance between the occasional inclusion of moderate and high FODMAP foods (naturally rich in healthy prebiotics) and adequate symptom control.  In the long-term, we advocate people follow the least restrictive diet necessary. Further research into the rechallenge and long-term maintenance phases of the diet is warranted.

Martin, L., van Vuuren, C., Seamark, L. (2015) Long term effectiveness of short chain Fermentable carbohydrate (FODMAP) restriction in patients with irritable bowel syndrome. Gut, 64: A51-A52.


  1. What about a long-term elimination diet? I know a lot of people just stick to the strict phase of the diet and never get on with rechallenging.

    Maria Skau from Norway.

    1. I can really see why! If you have suffered and do suffer from this wretched condition, you are likely to want to maintain the relief. People say it is so restrictive, but I was only eating chicken, rice and eggs as my mainstay so this list of possible foods is wide to me.

  2. Hi. I have a comment on the statement "Given the adverse changes in gut microbial populations associated with long-term adherence to a low FODMAP diet..." The study that is listed as a reference does not draw any conclusions regarding adverse effects on gut microbiota. There is a study that reveals changes, both on numbers (decreased) and in diversity (increased) (Halmos et al. Gut 2014) but as far as I know, the jury is still out on what this actually means? Do you have some "inside information", or are you maybe jumping to conclusions here?