Low FODMAP Diets

Why bother?

The Low FODMAP Diet has been scientifically proven to reduce and even eliminate the symptoms of Irritable Bowel Syndrome (IBS) in over 75% of people who try it. (Wait! What are FODMAPs?) The Low FODMAP Diet can be challenging, but totally worthwhile sticking to. Below we go into detail about the three phases of the diet and we’ve included some top tips along the way to help you succeed.

As with any diet, but particularly due to the large amount of foods you will be eliminating to start with on this one, I cannot express enough how much I recommend you to seek advice and guidance from a registered and FODMAP trained dietician. The diet can be difficult to follow, and whilst you are thinking of what meals you could make and scanning food labels for ingredients, you don’t want to be worrying about whether you are getting enough fibre or nutrients etc. Ask your dietitian to help you create a balanced diet and meal plans – it’ll be worth it!

The three stages of a Low FODMAP Diet

The Elimination phase is by far the hardest to conquer but at least it’s out of the way first. The elimination phase should last for around 6 weeks and this is where you remove ALL moderate and high FODMAP foods from your diet. Most people start to see a significant improvement in their symptoms after a week or two of being FODMAP Free! You should be in the Elimination stage for around 4-6 weeks depending on how good your symptoms are.

One of the hardest parts of this stage for me wasn’t the will power to resist high FODMAP foods (the need to get rid of these symptoms far outweighed the desire for any high FODMAP foods!), it was learning and remembering which foods were safe! For this, I found the Monash app really helpful and I still use it regularly.

Top Tip!

Remember to check serving sizes – whilst some foods can be moderate or high in FODMAP’s, you might find there is a smaller serving size which is safe, meaning you don’t have to eliminate that food altogether. An example of this is Beetroot – on the Monash App, Beetroot is High in FODMAPs (Oligos in this case) at 40g, but Low in FODMAPs at 20g.

Top Tip!

Don’t start the elimination phase at a time when it will clash with something that will make the diet super hard to follow – like Christmas or your summer holiday. Once you are through the first few weeks of the diet, it will become easier and eventually become second nature to you. However, if you start the diet two weeks before Christmas, you won’t have had time to build up your routine and your will power to resist high FODMAP foods.
This stage is all about testing your body, to see which FODMAPs it can tolerate and at what quantities. Most people are able to reintroduce a selection of foods back into their diet and will single out the particular triggers which they will continue to avoid.

It is vitally important you go through this stage, to ensure you can reintroduce as many foods as your body will allow – which will give you a much more balanced diet, as well as make the diet easier to follow (particularly when eating out as you will eventually have a much smaller list of foods to avoid) and so it will give you more variety too!

So, how to go about the reintroduction phase?

There is lots of advice and many ways to go about doing this, but I will explain my version and you can discuss this with your dietitian to see if they agree and can help you with this.

  • Continue with the elimination diet as you have been doing for the past 4-6weeks.
  • Then every Wednesday introduce one new food and have a high FODMAP serve of that food for three consecutive days (Wednesday, Thursday and Friday).
  • For the following four days exclude the high FODMAP food from your diet again and monitor your symptoms. Depending on how you felt and the severity of any symptoms, you can determine if it was a successful reintroduction or not.
  • You are then at another Wednesday, by which time any symptoms from the previous test should have cleared allowing you to start the next reintroduction test.

Some foods, I would be fine with and have no flare up at all, whilst others I might react very quickly to or within the three days of testing it. If so I would stop consuming the food and carry on with my diet as it had been. Then by the following Wednesday my symptoms would have cleared and I would start the next reintroduction test.

Top Tip!

If you react badly to a food, make sure you try to reintroduce it again at a later date and try with a smaller serving size to start. Just because it didn’t go well the first time, doesn’t mean that’s it – remember other factors play a part in our symptoms too like stress or lack of sleep. So it might not have been all down to that one food.

Top Tip!

For the first four reintroduction tests, I would choose a food which is high in just one of the four categories, so for example:

Honey – high in Fructose
Cow’s milk – high in Lactose
Garlic – high in Oligos
Sweet potato – high in Polyols

Whilst it’s not quite as clear cut as this, if my Lactose and Oligos tests were successful, I would continue the reintroduction with a selection of foods high in Lactose and Polyols to see if they would be as successful. After I had managed to reintroduce some foods, I would then turn to the groups which weren’t so successful – Fructose and Oligos in my case. I haven’t managed to reintroduce garlic or onion to my diet, however there are other foods moderate in Oligos which I have found to be ok, for example beetroot.

The same goes for Fructose – I still can’t tolerate apples, but I can tolerate some mango. Everybody is different, so you need to go through the reintroduction process to find your tolerance levels to foods.

Some people call this the Maintenance phase – but I think Maintenance sounds negative and hard work, so I like Continuation as you are continuing the success of the Low FODMAP Diet!

So, the continuation phase is just that – continue with the diet and include the foods you have successfully reintroduced. Now you know the foods you will be continuing to eat, your dietitian will be able to help you with meal plans and advise on any supplements to ensure you are getting a good balance of protein, fibre, fats, vitamins and minerals every day, to lead a healthy lifestyle.

Resources to help with a Low FODMAP Diet

To follow this diet through all stages there are a few things I have found helpful which I have included in this blog post:
Top 5 resources for those suffering with IBS (in UK)


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