If you suffer from IBS, avoiding certain foods could seriously ease your symptoms. Here's why the FODMAP diet may help you

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From bloating to cramps to constipation that alternates with diarrhoea, IBS  is the kind of health condition that you wouldn’t wish on your worst enemy. There’s no ‘cure’ or magic bullet to ease the symptoms, and the fact that it’s a chronic condition means that more often than not, you’re stuck with it for life, albeit on and off in terms of frequency and severity of relapses.

The NHS lists ‘diet and lifestyle management’ as one of the principal ways to reduce symptoms and improve your quality of life, but it can be difficult to stay on top of all of the potential triggers, namely, stress, caffeine intake, fat in your diet, general gut sensitivity and sadly, chocolate, to name but a few possible culprits. There is, however, one key change that you could make that has been known to improve, or even eliminate, symptoms for approximately 70 per cent of IBS sufferers according to experts at King’s College London; go low FODMAP. If you’re wondering what the frig a FODMAP is, read on…

What are FODMAPs?

Nutritional therapist Emma Olliff  reveals the meaning behind the acronym: “It stands for Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols.”

Quite the mouthful. Emma breaks it down further:

“Basically FODMAPs are a group of naturally occurring sugars that are not absorbed in the small intestine. Instead, they travel down to the large intestine where bacteria are present, which is normal and healthy. These bacteria use the unabsorbed sugars (FODMAPs) as a  food source. When the bacteria eat the FODMAPs, they ferment them, which releases gas that in some people leads to excessive flatulence, gassiness, abdominal distension and pain and may lead to constipation, diarrhoea or both.”

The theory of eliminating high FODMAP foods from the diet in order to ease IBS symptoms was first put to the test by Dr Sue Shepherd in 1999, and her PhD research has proved somewhat groundbreaking for many sufferers. A diet plan was subsequently developed by a team at Monash University in Melbourne, with FODMAP trained dietitians tailoring low FODMAP diets to patients’ individual health needs and lifestyles.

So successful was the low FODMAP approach, that it was adapted for UK patients in 2009 by research staff at King’s College London, and as nutritional therapist Gabriela Peacock  highlights, on our shores “it is typically managed through a clinician, be that a nutritionist or dietitian. Some hospital dietitians specialise in it.”

High and low FODMAPs

So where exactly are FODMAPs hiding? Unfortunately, in some seemingly pretty disparate places on initial consideration. High FODMAP foods include apples, baked beans, yoghurt and the much hailed health bomb, avocado. To go low FODMAP, you’ll need to make some serious shopping lists, as IBS sufferer and low FODMAP fan Ellie Clarke, 24, confirms:

“I’ve been battling severe IBS symptoms for the last five years, suffering from unpleasant bloating, unpredictable bowel movements (sorry!), and extreme fatigue.

“From my research, my experiences seemed to be symptomatic of a gluten and/or dairy intolerance, and therefore my first step was to cut out both entirely. Although this alleviated some of my symptoms, I was by no means feeling my usual energetic self and was still experiencing excruciating abdominal pain much of the time.

“At this point I felt very depleted. The doctors I had seen weren’t advising me on anything that I hadn’t already tried, and my symptoms seemed to be getting worse again.

“My mum told me about the FODMAP diet just over a year ago, after she had spent an evening with a IBS dietitian and FODMAP specialist who recommended I give it a try. From then on I became hugely engaged in the different ways of managing IBS and did a lot of my own research on the diet. The work by Monash University seemed to be really forward-thinking, and the results and case studies I read about sounded incredible. However to begin with, I really struggled with the notion of cutting out some of my favourite fruits and vegetables: avocado, chickpeas, apples, beans, lentils, beetroot… so it wasn’t until I was completely bed-bound and exhausted that I decided it was time to give it a try.

“For me, the most important part of embarking on the low FODMAP diet was changing my attitude. I had to think positively about all of the amazing, nutritious ingredients that I COULD eat that wouldn’t make me feel awful afterwards, rather than worrying about all those things I’d be missing out on. I strongly believe that this is key. Also, whilst I familiarised myself with the diet, I printed out a list of low FODMAP foods to take with me to the supermarket, ensuring that I only shopped from that list to avoid the risk of temptation! My weekly food shop and cupboard staples now look something like this:



Green beans

Broccoli (high FODMAP but fine for me in moderation)

Sweet potatoes (also high FODMAP but fine for me in moderation)

Red and yellow peppers






Fish fillets


Brown rice





Almond butter

Chia seeds

Buckwheat flour, to make bread, cookies, etc!

Sweetener – 100 per cent pure maple syrup

Rude Health almond milk

Will a low FODMAP diet treat IBS?

Before rushing to the shops with Ellie’s list, however, it’s important to acknowledge that a low FODMAP diet doesn’t necessarily look the same for everyone, nor can it work miracles for the masses, as Emma underlines:

“I have found this diet to be useful for some of my IBS patients. It is not appropriate for all IBS patients, however. IBS is basically a term used by doctors to diagnose patients that have a collection of digestive issues that cannot be attributed to another disease. So if someone has IBS due to FODMAP sensitivity, then this is a great diet for them to follow. If they have IBS due to another trigger, then this may not be the best approach.

“Because this diet isn't necessarily going to improve everyone's IBS symptoms, and because this is quite a tricky diet to follow, I would recommend that my client takes a hydrogen breath test to determine whether this diet is suitable. The test works on the basis that bacteria in the large intestine produces hydrogen by fermenting carbohydrates.

"Some of the gas produced will be passed out as flatulence, but most will be transferred across the lining of the large intestine. The gases then dissolve into the blood and the blood carries it to the lungs where it will be breathed out, and for the purpose of this test, measured.”

A hydrogen breath test is of course very enlightening, but other tests are also recommended to rule out digestive conditions other than IBS, as Gabriela emphasises:

“It is sensible to have a range of tests before embarking on any kind of low FODMAP diet. A doctor can also eliminate other serious medical conditions such as coeliac, IBD or Crohn's disease.”

How to try a low FODMAP diet

While going it alone on a low FODMAP diet is indeed possible (Emma advises arming yourself with a cookbook authored by Dr Shepherd  and a more general collection of gut soothing recipes ), professional supervision is strongly suggested by experts in the FODMAP field. Gabriela explains why professional guidance is especially key when transitioning to a low FODMAP diet:

“Getting started can be daunting. Some people experience constipation, so might need to increase low FODMAP fibre-rich foods. You will also need to keep a food diary which can be a struggle for some people.

“In addition, portion size is an important consideration in the manifestation of IBS symptoms. It’s also worth bearing in mind that many pre-made products and sauces contain high FODMAP ingredients. For example, you need to avoid products made with high FODMAP fruits and vegetables (particularly onions and garlic), high fructose corn syrup (HFCS), inulin, honey and wheat. It is advisable to start reading labels!”

In case that makes you feel as though you don’t want to touch the low FODMAP diet with a bargepole, it’s vital to appreciate that low FODMAP isn’t for life. As Gabriela clarifies, you should be removing high FODMAP foods from your diet only for a controlled amount of time:

“The elimination phase is two to six weeks. Due to the complexity of the low FODMAP diet, a two week elimination period is often not long enough, as it can take longer than two weeks before you stop accidentally consuming high FODMAP foods. In reality it is likely that you will stay in the elimination phase of the diet for two to six weeks before starting the reintroduction phase. Once your symptoms are under control you can then start the reintroduction phase with the guidance of your dietitian or nutritionist.

“Each individual is unique, and we all have different factors contributing to our digestive health. Each IBS sufferer has different symptoms and triggers, so each reintroduction phase will pan out differently. However, research shows that patients with IBS who consumed a low FODMAP diet experienced a significant improvement in symptoms and changes in their microbiome, suggesting that immune signalling and alterations in the microbiota could be important markers for some IBS sufferers.”

Keep it short-term

Staying on a strict low FODMAP diet long term, however, could harm rather than help our microbiomes, as King’s College Professor of Epidemiology and lead investigator of the British Gut Project Tim Spector warns in  The Diet Myth :

“The diet cuts out many foods including wheat, legumes, pulses, and some fruits and vegetables. It can result in a dramatic improvement in symptoms in some IBS sufferers, but the results are hard to predict. The downside to this diet is that the restricted foods contain lots of important nutrients, including fibre and vitamins as well as polyphenols, and there may be adverse effects on the health and diversity of many people’s microbiome.

“Talking about our diets in general, a lot more fibre needs to be consumed. We currently eat much less than we should and we cannot afford to permanently cut out these major and varied sources of fibre and nutrients on the back of the latest restrictive health craze.”

The bottom line? Unless you’re one of the one in five people wrestling with IBS in the UK, it’s actually not healthy to be forgoing FODMAPS. If you are troubled by IBS, however, a bespoke low FODMAP diet may not only boost your quality of life but it could also alleviate pressure on the health system, as according to dietitian Emer Delaney, 14% of GP budget goes towards medication to treat IBS symptoms.

Getting to grips with FODMAPS has certainly been a gamechanger for IBS sufferer Ellie: “After one week on the low FODMAP diet, I felt better than I had done for years; it was so exciting and literally changed my life! At the same time I also started taking Symprove , a live probiotic  proven to alleviate the symptoms of IBS, something I now swear by and think is worth every penny.

“I’ve since been closely following King’s College’s investment into FODMAP, and am so pleased to see that they are now delivering a three day FODMAP specialist course for dietitians. In fact, I read somewhere that this year they will be announcing a low FODMAP diet as the official treatment for IBS! It’s great to see so much progress in the field, and hopefully over the next few years we will see all GPs being in-the-know. Did you know that there is now a low FODMAP certification sticker on some foods in Australia?!

“I would advise anyone suffering from IBS-related symptoms to speak to their GP about the low FODMAP diet before eliminating certain food groups such as dairy and gluten. Either the GP will know about the diet, or refer you to someone who does. They will talk you through the elimination and reintroduction phases, and will arm you with some handy booklets to support you through the low FODMAP process.”

A lifeline for IBS sufferers; the low FODMAP diet is anything but a fad, but it certainly isn’t for everyone.

Check out our  review of the low FODMAP recipe book here

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