I originally wrote this post in March 2016 for Nicer Foods who were one of the first ever low FODMAP product companies. Since that time Nicer Foods has been incorporated into FODY Foods and this useful article is no longer available. Therefore I have reproduced it here along with the previous forward of the article by Katelyn Collins RD who worked for Nicer Foods.
Foreword by Katelyn Collins
We are a big fan of Lee Martin, RD here at Nicer Foods! Lee is an expert in travelling while on the low FODMAP diet and we were lucky enough to contribute to his travel blog. He is also an expert in re-challenging FODMAPs and has written an incredibly helpful book on the topic. If you are moving into the re-challenge phase of the low FODMAP diet, we highly recommend that you get yourself a copy of the book and also take a look at Lee’s helpful tips below!
Authored by Lee Martin MSc RD
Re-challenging FODMAPs is an integral part of the low FODMAP diet and is when you test your tolerance levels to individual FODMAPs. This helps you work out which FODMAPs trigger your symptoms and at what portion sizes you can consume the individual FODMAPs before you start to experience an increase in symptoms. Re-challenging FODMAPs can be a confusing process if not approached correctly so bear these points in mind when you get started.
Continue to follow a low FODMAP diet
This might seems like an obvious one but the reintroduction phase will take about 10 weeks to complete and during this time it is important you continue to follow a low FODMAP restriction diet. When you are testing your tolerance levels to different FODMAPs you need to make sure the only thing that is different in your diet is the FODMAP that you are testing, even if you have successfully trialled certain FODMAPs.
Where to start re-challenging?
When deciding on which FODMAPs to re-challenge first there are no ‘rules’. Most people will want to re-challenge the foods they missed the most from following the low FODMAP restriction diet. Often the FODMAP fructans are chosen first as they include wheat bread, garlic and onion which are all popular foods, however this may not be the easiest FODMAP to start with. As fructans are found in a wide variety of foods you need to re-challenge several different foods, for example wheat based sources such as bread or pasta, or vegetable sources of fructans such as garlic and onion. For other FODMAPs you only need to do one re-challenge, for example for the FODMAP fructose you can use mango, or for the FODMAP sorbitol an avocado can be used. These FODMAPs are easier to re-challenge to start with to help you get used to the re-challenge process and discover what FODMAPs are your triggers.
How long does the re-challenging take?
Normally if you are re-challenging for 3 days and leaving a washout period for 3 days then this re-challenge process lasts almost a week. Therefore 10 re-challenges can easily become 10 weeks with a different re-challenge completed each week.
Here is an example of 10 common re-challenges for all the FODMAPs, all recommended in the book (Re-challenging and Reintroducing FODMAPs).
As you can see there are 5 re-challenges for fructans and one re-challenge for each of the remaining FODMAPs. In total there are 30 days of re-challenges plus 30 days for a washout period, therefore overall (theoretically) the re-challenges will take 60 days. This may take longer if life events get in the way or if you experience severe symptoms which take a while to dissipate. Or it may be shorter if you react to the FODMAPs after day 1 or 2 and cannot (or do not need) to complete all three portion size tests. You should be aware that there is misinformation on reintroduction phase available on the internet and I suggest you read this article to help understand what could be old and outdated.
Which meal do you choose to try for a FODMAP re-challenge?
Choosing when the best time or what the best meal is to attempt a FODMAP re-challenge will largely depend on the food, your personal preferences and how you would normally consume that food in your typical diet. If we take milk as an easy example, most people will consume larger quantities of milk with cereal or in a smoothie, which is usually at breakfast time. If this is typical for you then this is obviously a good time to re-challenge lactose with milk.
Certainly some of you may be a bit concerned about re-challenging a FODMAP in the morning and then going to work, in which case you may only want to try a food challenge at home in the evening at dinner to avoid a bad symptom experience or being ‘caught out’. Be cautious not to re-challenge too late in the evening before going to sleep however. The problem here might be that if you experience mild symptoms when you are asleep (unnoticed) and then have that FODMAP at lunch and experience symptoms later in the day it can confuse things.
Preparing meals for re-challenging: Will you choose the easy way or the hard way?
When it comes to the actual meal you need to decide how easy or hard you are going to make it for yourself to include the food you wish to re-challenge in the meal. There are many ways to do this but I will give you two examples starting with the easy one first.
Make it Easy:
Cook the same low FODMAP meal (one you know well and are happy it doesn’t affect symptoms) on each of the days you are re-challenging and cook the FODMAP containing food separately to have with the meal. Simply increase the portion size of the FODMAP containing food you are re-challenging each time. This can be a bit boring but it does help control the meal so the only thing that is changing is the amount of FODMAPs consumed.
The Hard way:
The harder, but more interesting and realistic way is to incorporate the FODMAP food you are going to re-challenge into different meals and snacks. For example if you are re-challenging avocado then you may have some avocado as part of a dip, spread some on wheat free toast or have some in a low FODMAP salad.
Be sensible and systematic in your approach
For the reintroduction phase to be a success you need to approach it in a systematic fashion and follow a reintroduction protocol. There are two main ways of reintroducing which are discussed in this post. In the Re-challenging and Reintroducing FODMAPs book a full protocol and flowchart is provided to take you through the reintroduction phase in a step by step way.
Word of caution: It can be very tempting to try a re-challenge when eating out at a restaurant, although this is not the best option. You are not in control of the portion sizes and even though the food you are re-challenging may look the right amount you cannot be sure. Think how much vegetables shrink on cooking for example. In addition any sauces or dressings may contain other high FODMAP ingredients.
Finally be aware of usual dietary advice for IBS
As well as following a strict low FODMAP diet you also need to be aware of usual dietary advice for IBS. Things to remember include making sure that during the reintroduction phase you do not increase the amount of caffeine or alcohol (or smoking) that you normally consume. It is also worth remembering not to have large meals or go a long time without eating. Stick to a regular meal pattern with normal portion sizes of foods to lessen the chances of this upsetting your gut. Testing a FODMAP on an empty stomach is more likely to trigger symptoms. For more information on recommended dietary (and other) advice for treating IBS have a read of the article linked here which provides a list of things you should be aware of.