Reintroducing FODMAPs

(Updated 2017) by Lee Martin MSc RD

A new book on the reintroduction phase of the low FODMAP dietPlease note not all the information in this post (from 2013) is based on the latest research information and clinical practice advice regarding the reintroduction phase of the low FODMAP diet. The article has been left here for reference however after reading it you can read a more recent post entitled Reintroducing foods on the low FODMAP diet, Watch out for misinformation

The good news however is that the first ever book dedicated to reintroducing FODMAPs is now available to purchase on Amazon. The book is entitled ‘Re-challenging and Reintroducing FODMAPs – A self-help guide to the entire reintroduction phase of the low FODMAP diet‘. For more details visit the website

Reintroducing FODMAPs

Having now completed the low FODMAP diet for the full 8 weeks (time does really fly!) the next phase was to reintroduce the foods high in FODMAPs back into our diet.  Following the low FODMAP diet had become part of our daily eating routine, and after 4 weeks it quickly became fairly easy to follow with not much thought needed regarding appropriate choices required.  However, the diet is not designed to be forever, rather it is designed to reduce the overall load of FODMAPS in the diet to reduce  severity of symptoms – and then to re-introduce to your personal tolerance levels. This became tricky for us, given that we do not have a clinical diagnoses of IBS and were not looking for a significant reduction of symptoms. We did however find a change in symptoms from following a low FODMAP diet and as such were very interested to identify the exact problem FODMAP foods which increased symptoms when we reintroduced them.

 Some tips about how FODMAP reintroduction’s can practically be done

Fisrt you need to keep the low FODMAP diet rolling along in the background whilst reintroducing the right amount of test FODMAP food.  We found it can be difficult to incorporate this into meal planning, especially as you are meant to test a particular FODMAP food three days in a row.

One option is to just cook the same low FODMAP meal three days in a row and increase the dose of the test food (if your not getting any symptoms of course).  We decided to do it the harder, but more interesting way and incorporate the test foods into meals & snacks and an example of how we tested a high FODMAP food is shown below.

Example FODMAP Challenge

Test Food: Mushrooms
Test FODMAP: Polyols
Test Amount Day One: 40g (roughly 4-5 mushrooms depending on size)
Test Meal Day One: We had a meal at a chain restaurant and the chicken dish I ordered came with, what I’m going to guess, is about 40 grams of mushrooms or maybe just slightly less. Which worked out perfectly for my test on Day One!

Test Amount Day Two: 80g
Test Meal day Two: Gluten free pasta with homemade pesto & mushrooms

Test Amount Day Three: 120g (usually half a pack of supermarket bought mushrooms)
Test Meal Day Three: Garlic (infused oil) & parsley mushrooms on gluten free toast

Reintroducing FODMAPsI chose mushrooms because 1. I love them, 2. I missed them & 3. They fit into loads of meals I would usually cook 🙂 like this Polenta & Mushroom dish I cooked yesterday. Indeed I could also have used this meal as a suitable low FODMAP meal with a test food (mushroom) to challenge.

Some tests are definitely easier than others however; for example when you test fructans (such as wheat, onion, broccoli) which are found in many foods you will be glad there are some foods containing fructans that can be had as a snack rather than needing to incorporate them into a full meal. Bringing fructans back into the diet by trying 2 slices of bread was easy and enjoyable, and provided the first opportunity to enjoy some delicious fresh bread! There are many different foods which contain fructans, and so you should always test a few different ones (or more if you want), especially if you feel fructans are a particular problem for you.

Reintroducing FODMAPs
Mashed broad beans & parmesan cheese on toast! The benefits of reintroducing FODMAPs!

There are no rules to what foods you choose when it comes to the re-introduction phase, but it is likely more support may be required. At this point we would recommend for anyone following the diet to speak to your healthcare professional for more assistance and some pointers of where best to start.  Make sure you do complete the re-introduction phase fully so that you can incorporate as much variety of low FODMAP and high FODMAP containing foods into your diet. A wide variety is key to your digestive health and you may even find benefits once they are reintroduced. It is understandable why some people are reluctant to complete this phase fully especially if their symptoms have been significantly reduced by the diet and the thought of getting those symptoms back are quite scary.

IBS symptoms experienced from the reintroduction of high FODMAP foods may in some cases seem worse than before the low FODMAP diet was started

It is worth noting that the symptoms experienced from the reintroducing of high FODMAP foods may in some cases seem worse than before the low FODMAP diet was started. This may be due to slight changes in your tolerance levels to FODMAPs due to not having these foods in your diet for 4 weeks or more as well as changes to your gut microbiota.  Foods high in FODMAPs are also prebiotics, meaning they provide food for the good bacteria in your gut, which is a good thing and is an important part of a balanced healthy diet.  By not consuming foods containing these prebiotics you may affect the natural flora in your gut which could lead to more gastrointestinal and other problems in the future.  This is a very interesting topic which is being researched as part of the whole FODMAP evidence base. The main aim is to ensure you keep yourself and your gut healthy for the long-term.

Further articles on how to challenge FODMAPs and navigating the Reintroduction Phase of the low FODMAP diet

Top Tips to get you started when Re-Challenging FODMAPs

Re-Challenging and Reintroducing FODMAPs: The How, When, and Why

Testing FODMAPs: How does the reintroduction phase work?

Week 4 – Reintroducing FODMAPs

5 Common Mistakes When Reintroducing FODMAPs


Re-introduction of FODMAPs: is there an easier way?

Re-Introducing Onion & Garlic

Are You Ready To Reintroduce High FODMAP Foods?

My FODMAP Journey – Weeks 5 & 6

FODMAP Reintroduction Plan and Challenge Phase: Your Guide and FAQ

Reintroducing Fodmap foods

The difficulties in accessing current and reliable information on Reintroducing FODMAPs

Podcast Episode #20 Lee Martin RD Explains The Re-challenge and Reintroduction Phase Of The Low FODMAP Diet

Good news! The first ever book dedicated to reintroducing FODMAPs is now available to purchase on Amazon. The book is titled ‘Re-challenging and Reintroducing FODMAPs – A self-help guide to the entire reintroduction phase of the low FODMAP diet’. Click on the logo for more details.


Want more information on the low FODMAP diet and IBS? Click here or for low FODMAP recipes click here.

We recently travelled around the world and blogged about following a modified low FODMAP diet. See more on our FODMAP travel section.

Skype consultations half price We offer reduced rates for Skype consultations anywhere in the world. For more information and for contacting R&M Dietetic you can enquire here or email

24 thoughts on “Reintroducing FODMAPs

  1. Interesting post. I’d like to know more about prebiotics, as I only eat the basic low fodmap diet. All the reintroduced food groups gave me problems.

    1. What this interesting piece of research shows is that the low FODMAP diet can reduce the amount of bifidobacteria in the gut perhaps due to the lack of prebiotics feeding these bacteria. Bifidobacteria has been shown to have an important role in immune function and digestive symptoms in IBS therefore the theory is by continually having a low FODMAP diet and therefore having a lower amount of bifidobacteria you may be increasing your risk of further digestive problems or other future health issues. This is a general assumption and the reality, as with all research, is that each individual will be different. Also remember this piece of research was only for a few weeks and the long term effects have yet to be determined as have any detrimental effects long term from following the low FODMAP diet e.g. although in the 4 weeks in the study the amount of bifidobacteria decreased did this continue long term? did the bifidobacteria rebalance itself even if a low FODMAP diet was continued? did the levels of bifidobacteria increase when the re-introduction phase and normal diet were completed?
      More research is obviously needed and until we have all the answers the initial aim of the FODMAP approach should be remembered which is: to follow a low FODMAP diet to reduce severity of symptoms and then re-introduce to personal tolerance and consume as varied a diet as possible.
      If you haven’t achieved this goal it might be worth you going to see a dietitian to see what individualised advice they can give around what options are available to you.

      1. I’ve also been eating raw unpasteurized sauerkraut which I’ve heard is a FODMAPS friendly way to boost good gut bacteria?

    1. Hi Mike,
      The chances are a prebiotic supplement will be high in FODMAPs but this doesn’t necessarily mean it will increase symptoms. Some prebiotics, for example, Bimuno have been shown to help improve IBS symptoms when taken at the correct dose. At the moment there is not enough evidence to recommend a specific type of prebiotic so its trial and error for anyone who wants to try. It is definitely an interesting research theme for the future…….

  2. I am a RD as well and have IBS. The low FODMAP diet has alleviated my symptoms and I feel wonderful. The re intro phase is confusing to me since there are a few conflicting manners to re-intro the food groups. I agree that testing 1 food at a time seems the most sensible vs several different food from the same group in 1 day. However, it seems like this would take so long to get through each group. I am still contemplating what approach to use with my future clients.

    1. Hi Vanessa,
      Sorry I missed this comment it went into my spam! At the moment there is no universally agreed approach to reintroducing FODMAPs. My book discusses the two options most widely used and practised by the majority of dietitians in Europe and Australia. Usually the re-challenging part takes 10 weeks and this will help people to understand what individual FODMAPs and what portion size of these FODMAPs they can tolerate. This allows relaxation of the low FODMAP restriction diet and reintroducing FODMAPs back into the diet. To completely reintroduce FODMAPs and understand how the combination of FODMAPs triggers your symptoms is an ongoing process.

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