Should you stay on a low FODMAP diet permanently?


Interest in the low FODMAP diet has grown markedly in the last year and the diet is becoming popular with people from around the world who have been diagnosed with irritable bowel syndrome (IBS). Overall, this is a very good thing because it means that there are clear actions IBS sufferers (or even those who just suspect they may be sufferers) can take to improve their symptoms.

As a result, many who suffer bloating and discomfort, or other symptoms they personally attribute to their current diet, may choose to take up the diet long term without consulting an experienced dietitian or doctor. This may be an increasing trend into the future, for better or worse, as information about FODMAPs is made more readily available and it becomes easy to go onto the diet without consultation. In fact, we may see many people experiment with the diet simply as a result of conversations with friends, or through the increasing availability of low-FODMAP foods at the supermarket, in a similar way that gluten-free products have become a casual inclusion into many shoppers’ weekly purchases because those foods are sometimes perceived as a healthier alternative. IBS sufferers may also fear that their symptoms might return if they eat high FODMAP foods, and so the low FODMAP diet becomes a long term habit for them.

In contrast, Monash University researchers currently recommend that a low FODMAP diet be followed strictly for just two to six weeks until symptoms disappear, and not followed as a permanent diet for life. After that time, cautious reintroductions are encouraged as you learn your level of tolerance to individual high FODMAP foods.

How should high-FODMAP foods be re-introduced?

Your goal here is to see if any moderate-to-high FODMAP foods can be tolerated and for you to continue to have good symptom control. The process of reintroducing these foods will depend on the individual, your symptoms and their severity, and what your usual diet was. Some people may only be able to reintroduce a couple of foods and eat small quantities of those, while others may be able to tolerate many types of high FODMAP foods and eat them regularly.
The process is about finding a balance between continued good symptom control and reintroduction of some higher FODMAP foods. It may be beneficial to speak with a dietitian who specializes in the area during the reintroduction process, as they will be able to help you adjust the process to suit your needs and your symptom types, especially if you are trying to reintroduce foods for the first time or have been intolerant with them when previously reintroduced.

Why not go low-FODMAP full time?

Reintroduction of high FODMAP foods is important to your health for a number of reasons. Firstly, it ensures you have a varied diet, with a wide range of nutrient-rich foods. Secondly, research has shown that FODMAPs (especially fructans and GOS) are prebiotics – in other words, they are a food source for bacteria, encouraging the growth of good bacteria with potential health benefits.

A couple of research studies (from King’s College London and Monash University), started to examine possible changes to patients’ gut microbiota after being on the low FODMAP diet.  Both studies confirmed that individuals who persist with the low FODMAP diet do develop changes in their gut microbiota with some good bacteria populations declining. What this means for your gut health is not fully understood yet, so we’ll keep you posted as the research continues. What we do know is that IBS sufferers want to lower FODMAP intake in the short term to improve their symptoms because those foods are fermented and produce gas resulting in bloating and discomfort, however they probably need them in the diet in the long term to maintain the right balance of gut bacteria.

If you are on the low FODMAP diet, try and reintroduce some high FODMAP foods, if you are able to tolerate them. Everyone is different and you will need to work out your own tolerances. It is certainly worth trying and the researchers have found that many people end up with much less restrictive diets and only a few key foods they need to avoid.

Which high FODMAP foods are good to reintroduce first?

Canned legumes such as chickpeas or four bean mix contain low levels of prebiotic galacto-oligosaccharides – low enough that they shouldn’t produce significant symptoms, but high enough to slowly increase your prebiotic intake and encourage good bacterial growth. As an alternative pick one of your favourite foods that you’ve had to exclude whilst on the diet and try consuming a small amount first, building up over time.

If you are hesitant or unsure about how to proceed, we suggest you seek the advice of an experienced dietitian to assist you through the reintroduction process.

Will you completely stop the low FODMAP diet at some point?

Most people won’t end up eating exactly as they did before starting the low FODMAP diet, and are more likely to be on their own individual version of the diet, that includes many low and some high FODMAP foods. Flexibility is the key here and you may find that your tolerances and triggers change over time. This is an ongoing process of learning about your symptoms and what foods trigger them. Be patient with yourself as it is unlikely to be a perfect journey to intestinal health.