What is a Fermentable Oligo-, Di-, Mono-saccharides, and Polyols (FODMAP) diet?

From the Guidelines

A Fermentable Oligo-, Di-, Mono-saccharides, and Polyols (FODMAP) diet is a dietary approach that involves restricting the intake of certain types of carbohydrates that can be difficult for some people to digest, in order to manage symptoms of irritable bowel syndrome (IBS) 1.

Key Components of a FODMAP Diet

• The diet consists of three phases:
  • Restriction phase: lasts 4-6 weeks, where FODMAP intake is substantially reduced to determine if symptoms are linked to FODMAP intake 1.
  • Reintroduction phase: lasts 6-10 weeks, where FODMAPs are reintroduced one at a time to identify specific tolerances and intolerances 1.
  • Personalization phase: where the diet is individualized based on the patient's specific tolerances and intolerances 1.
• FODMAPs are short-chain fermentable carbohydrates found in various foods, including fruits, vegetables, dairy products, artificial sweeteners, and wheat 1.
• The diet is typically supervised by a trained dietitian to avoid nutritional deficiencies and overly restrictive eating habits 1.

Benefits and Considerations

• A low FODMAP diet has been shown to be effective in reducing symptoms of IBS, including abdominal pain and bloating 1.
• However, the diet can be complex and may require significant changes to a person's eating habits 1.
• It is essential to work with a healthcare professional or registered dietitian to ensure a well-planned and balanced diet 1.
• Some studies suggest that a low FODMAP diet may also have benefits for anxiety and depression in patients with IBS, but more research is needed to confirm this 1.

From the Research

Definition of FODMAP Diet

• The FODMAP diet is a dietary approach that involves reducing the intake of fermentable oligo-, di-, mono-saccharides, and polyols (FODMAPs) to manage symptoms of irritable bowel syndrome (IBS) 2, 3, 4, 5, 6.
• FODMAPs are a group of highly fermentable but poorly absorbed short-chain carbohydrates and polyols that can exacerbate intestinal symptoms by increasing small intestinal water volume, colonic gas production, and intestinal motility 6.

Mechanisms of FODMAP Diet

• The low FODMAP diet works by reducing the amount of FODMAPs in the diet, which can help to reduce symptoms of IBS such as bloating, abdominal pain, and changes in bowel habits 2, 3, 4, 5.
• The mechanisms of the low FODMAP diet are not fully understood, but it is thought to involve the reduction of luminal distension induced by gas and water, as well as the modulation of visceral hypersensitivity, increases in intestinal permeability, and the induction of microbiota changes 2.

Effectiveness of FODMAP Diet

• Studies have shown that the low FODMAP diet can be effective in reducing symptoms of IBS, particularly bloating and diarrhea 3, 4, 5.
• A meta-analysis of clinical studies found that the low FODMAP diet was superior to a standard IBS diet in improving symptoms of IBS 4.
• A randomized controlled trial found that the low FODMAP diet reduced overall gastrointestinal symptom scores, stool frequency, and consistency compared to a general dietary advice group 3.

Limitations and Risks of FODMAP Diet

• The low FODMAP diet can be restrictive and may lead to a reduced intake of certain nutrients, such as fiber, calcium, iron, zinc, folate, B and D vitamins, and natural antioxidants 6.
• The quality of the evidence for the low FODMAP diet is lower than optimal due to methodological flaws, such as lack of a proper control group and/or lack of blinding 6.
• The long-term effects of the low FODMAP diet are not well understood, and there is a need for further research to determine its safety and efficacy 2, 6.