Today we will turn our eye to phase 1 of the low FODMAP diet. And its possibly the most complicated phase at that – the elimination phase.

As I have mentioned before, I myself follow the low FODMAP diet. And honestly, when I was starting off the diet myself, I found that getting my head around this complicated first phase of the diet took a lot of studying, checking and double checking. To some extent, I found myself first just munching away on the foods that I knew were freely allowed, and then I gradually widened my horizons to foods that are allowed in specific quantities.

What is the low FODMAP elimination diet?

The low FODMAP diet is a diet that has been shown to reduce symptoms of irritable bowel syndrome for up to 86% of people with IBS. The diet works by avoiding certain foods that are easily fermented in the gut. Before trying the low FODMAP diet, it is worth trying easier and less risky diet changes first, which are often known as the first-line dietary strategies. I discussed these in my second video of this series.

The low FODMAP diet for IBS requires you to work your way through 3 different phases; The elimination phase, followed by the reintroduction phase and finishing with the maintenance phase.

Today, we will home in on the first and possibly most complicated phase of the diet: the elimination phase. We recommend that you follow this diet under the supervision of a registered dietitian, as it can be very tricky to get all the nutrients you need while you are working your way through the elimination phase.

How does the low FODMAP diet for IBS work?

The word FODMAP stands for the following: Fermentable, Oligosaccharides, Disaccharides, Monosaccharides And Polyols. During this first phase of the low FODMAP diet, you try to eat a diet that is low in these fermentable carbohydrates.

Each of these types of sugars, are easily broken down in the gut by bacteria, and the fermentation that can then take place in our guts can create gas, and can leave us feeling bloated, sore and constipated (or give you diarrhoea depending on the type of IBS that you have).

So the idea of the elimination phase of the low FODMAP diet for IBS is to avoid foods that contain high levels of these fermentable carbs.

How long do I need to avoid these high FODMAP foods for?

You do this for a set period of time, and you keep a close eye on your bowel habits and IBS-type symptoms. Usually this phase is trialled for 4-8 weeks. And it is important to know that people who have the type of IBS that causes more diarrhoea may see results faster than those who suffer more with constipation.

Either way, if your symptoms improve significantly during the trial period, then great, you are luckily someone who responds to the diet. At this stage, when your symptoms have improved enough, you can then enter the reintroduction phase of the diet where you bring each FODMAP group back into your diet carefully and try to figure out which exact group of carbs you respond to. However, if your symptoms do not improve enough during the elimination phase, you are possibly someone who’s IBS symptoms are not related to high FODMAP foods. At this stage you can either go back to eating as you did before, or you can try and stick to the diet for a few weeks longer. However, it is not recommended that you stay in the elimination phase of the low FODMAP diet for prolonged periods of time. This phase of the diet is very restrictive and can put you at risk of nutritional deficiencies. So everyone on the low FODMAP diet must eventually move on to reintroduction and maintenance phases, or back to their usual eating habits.

So what foods do I need to avoid when I follow the elimination phase of the low FODMAP diet?

Well in this video I will go through some of the more common high FODMAP foods to avoid. However, some foods will be allowed but in very small amounts. Its really down to avoiding portions of FODMAP containing foods that are likely to cause symptoms.

There are some apps that are very useful in helping you find out what portions of foods are considered low or high in FODMAPS. For example, the Monash low FODMAP app is regularly updated with their latest FODMAP test results. Further below I have also included some useful tables of foods to avoid and portions of foods that you can take while on the low FODMAP elimination diet. You can print these off and have them with you when going grocery shopping for example.

Firstly, I will go through the high FODMAP foods to avoid by food group. Afterwards, I will take a slightly closer look at exactly what foods you can find each of the 4 types of fermentable carbohydrate in.

Cereals on the low FODMAP diet:

During this phase of the diet, you will need to avoid all foods made from rye, wheat, barley, spelt and other grains such as amaranth, kamut and bourghal.

Generally, grain and carbohydrate foods made that are gluten free or are made from oats are low fodmap. This can include glutenfree bread and breakfast cereals. Rice, potatoes, quinoa, polenta and corn products also tend to be low FODMAP. Surprisingly, sourdough spelt bread is also low FODMAP as long as you take no more than 2 slices at a time. Sourdough bread has already been fermented to some extent, meaning there is less fermenting left to do once it reaches your gut!