Research update: What makes a good 3-step FODMAP diet?

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The Monash FODMAP Team, 12 August 2022

A 2022 review paper written by researchers from The Monash FODMAP team aims to explore ways to optimise the delivery of the FODMAP diet in gastroenterological practice from a dietetic perspective (1). We have summarised the review in a Q&A approach below for you!

The 3-step FODMAP diet - is it for every patient?

The traditional ‘3-step FODMAP diet’ approach involves restricting all FODMAP-containing foods, before reintroducing FODMAPs that are tolerable for the patient and personalising a FODMAP diet that can be followed for the long-term to achieve symptom control. 

However, an alternative FODMAP ‘gentle’ approach may be considered in some IBS patients instead. This approach involves restricting:

  • Foods that are highly concentrated in FODMAPs, and/or  
  • Foods high in specific FODMAPs, if they are suspected of triggering symptoms

Examples of IBS patients who may be suitable for the ‘gentle’ approach include, but are not limited to: 

  • Individuals with malnutrition
  • Individuals who found the traditional FODMAP diet too rigid to adhere
  • Children or elderly

What does the dietetic process involve in clinical practice?

The dietetic management of IBS often occurs in the out-patient setting. We have summarised in the table below the three key elements of nutrition consultation that are essential in working with the patient to achieve symptom control:


What are the risks that gastroenterologists should be aware of when implementing the low FODMAP diet?

Nutritional risk - Research has shown that patients who adhere strictly to the low FODMAP diet or followed the diet without the guidance of a healthcare professional had lower intakes of a range of micronutrients than those who adhered less strictly or are guided (2,3), respectively. It is recommended that high FODMAP foods should be substituted with nutritionally nourishing alternatives

Psychological risk - Preliminary evidence suggests a relationship between IBS and eating disorders. Eating disorders associated with IBS are thought to be associated with restrictive food choices. For example, one study found that 44% of individuals with avoidant/restrictive food intake disorder (ARFID) were prescribed a FODMAP diet by their gastroenterologist (4).

Patients with an active eating disorder diagnosis should not be placed on a FODMAP diet. Instead, non-diet approaches should be considered in this population. 

For patients who were not diagnosed with an eating disorder but are at risk or exhibiting disordered eating behaviours, the following approaches may be more appropriate:

  • A discussion of the pros and cons of a restrictive diet
  • Advice and recommendations on non-diet therapies
  • Consider a FODMAP gentle approach

What are some strategies that may be useful to increase adherence to the FODMAP diet?

The use of technology - Similar to published papers, FODMAP contents and information on printed information sheets are often (5-7):

  • Overly simplistic
  • Inappropriate to the personal backgrounds of patients
  • Highly different between sheets

These issues make compliance to a FODMAP diet challenging and confusing for clients.

On the other hand, the use of technology, such as the Monash FODMAP app, ensures that patients receive updated FODMAP information from a comprehensive database. They can also use the application according to their own clinical needs and cultural or social preferences.

The involvement of a multidisciplinary healthcare team (including a dietitian, of course!) - Studies found a higher proportion of patients with symptom improvement when IBS treatment is managed by a multidisciplinary healthcare team (compared to being managed by a gastroenterologist alone) (8). Another study found that the absence of a dietitian’s involvement resulted in low compliance to the diet (9). Members of a multidisciplinary healthcare team may include but are not limited to: Gastroenterologists, dietitians, physiotherapists, psychiatrists etc.    

What if a dietitian isn’t available?

Although evidence and clinical guidelines recommend delivering the FODMAP diet under the guidance of a dietitian, access to a dietitian is not always available, depending on the local healthcare system of the patient. Here are some recommended ways to overcome the absence of a dietitian when delivering the FODMAP diet:


Into the unknown 

What should we do if the FODMAP content of a food is unknown? We can either:

  • Assume the unknown food is okay to consume and only restrict foods with a known high FODMAP content. The unknown food will need to be restricted if symptoms do not improve adequately using this approach. or;
  • Restrict both high FODMAP foods and the unknown food, then re-introduce the unknown food back to the diet with a smaller than usual serving size (while monitoring for symptoms)

Monash University is always looking for cultural foods from around the world to test their FODMAP content. For patients coming from multicultural backgrounds, it may be useful to remind them that:

  • Protein-rich (e.g. plain meat/seafood and eggs) or high-fat foods (ghee, sesame oil) with little to no carbohydrate are low in FODMAP and may be used moderately in a low FODMAP diet
  • There are many Western foods with known FODMAP content that can be used in cuisines from around the world. Using Asian cuisine as an example, spring onion (green tops), bean shoots, curry leaves, soy milk (derived from soy protein), dragon fruit and starfruit are low FODMAP options that Asian IBS patients can continue to enjoy. 


  1. Sultan N, Varney J, Halmos E, Biesiekierski J, Yao C, Muir J et al. How to Implement the 3-Phase FODMAP Diet Into Gastroenterological Practice. Journal of Neurogastroenterology and Motility. 2022;28(3):343-356.

  2. Pourmand H, Keshteli AH, Saneei P, Daghaghzadeh H, Esmaillzadeh A, Adibi P. Adherence to a low FODMAP diet in relation to symptoms of irritable bowel syndrome in Iranian adults. Dig Dis Sci 2018;63:1261-1269.

  3. Ostgaard H, Hausken T, Gundersen D, El-Salhy M. Diet and effects of diet management on quality of life and symptoms in patients with irritable bowel syndrome. Mol Med Rep 2012;5:1382-1390.

  4. Harer KN, Jagielski CH, Riehl ME, Chey WD. 272-avoidant/restrictive food intake disorder among adult gastroenterology behavioral health patients: demographic and clinical characteristics. Gastroenterology 2019;156:S-53.

  5. San Mauro Martín I, Garicano Vilar E, López Oliva S, Sanz Rojo S. Existing differences between available lists of FODMAP containing foods. Rev Esp Enferm Dig Published Online First: 1 Feb 2022. doi: 10.17235/reed.2022.8463/2021.

  6. McMeans AR, King KL, Chumpitazi BP. Low FODMAP dietary food lists are often discordant. Am J Gastroenterol 2017;112:655-656.

  7. Trott N, Aziz I, Rej A, Surendran Sanders D. How patients with IBS use low FODMAP dietary information provided by general practitioners and gastroenterologists: a qualitative study. Nutrients 2019;11:1313.

  8. Basnayake C, Kamm MA, Stanley A, et al. 409 randomised trial of multi-disciplinary versus standard gastroenterologist care for functional gastrointestinal disorders. Gastroenterology 2020;158:S-77.

  9. Van Ouytsel P, Szalai A, Van Gossum A, Arvanitakis M, Louis H. Feasibility of a low FODMAPs diet without initial dietician intervention in the management of patients with irritable bowel syndrome: a prospective study. Acta Gastroenterol Belg 2021;84:593-600.

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