What is a low FODMAP diet?

Have you ever suffered with bloating or abdominal pain? Did you know certain carbs could be contributing to your discomfort? Dietitian Emer Delaney explains the low FODMAP diet and how it can help.

What is a low FODMAP diet?

If you've ever suffered from irritable bowl syndrome (IBS), you'll quite possibly have heard of the low FODMAP diet, which cuts out certain carbohydrates for a period of time to reduce or even eliminate symptoms. IBS is a chronic, relapsing and often life-long condition, and symptoms include abdominal pain, bloating and a change of bowel habit. More than four million people in the UK suffer from IBS and people visit their GP between three to ten times for help. There is a tendency to prescribe medication first to help manage symptoms, and GPs spend 14% of their budget on this. But what about the role of diet in treatment?  Research shows that up to 86% of people who follow a low FODMAP diet notice a significant improvement in symptoms.  

What are FODMAPs?

The catchy acronym stands for fermentable oligosaccharides, disaccharides, monosaccharides and polyols, which are more commonly known as carbohydrates. These can be further divided into five groups called fructans, galacto-oligosaccharides, lactose, excess fructose and polyols. The diet originated in Australia and has been adapted for the UK by researchers at Kings College, London. In essence, FODMAPs are different carbohydrates found in a wide range of foods including onions, garlic, mushrooms, apples, lentils, rye and milk. These sugars are poorly absorbed and pass through the small intestine and enter the colon, where they are fermented by bacteria.  Gas is then produced, which stretches the sensitive bowel causing bloating, wind and pain. This can also cause water to move into and out of the colon, causing diarrhoea, constipation or a combination of both. People with IBS are more susceptible to the problems that are associated with this.   

How to follow a low FODMAP diet

Under the supervision of a dietitian, high FODMAP foods are eliminated from the diet for six to eight weeks and replaced with suitable alternatives.  After this, small amounts of FODMAP foods are gradually re-introduced to find a level of tolerance without the symptoms returning. It is not designed to be a ‘diet for life’ as many high FODMAP foods are important for stimulating the growth of beneficial bacteria in the gut. 

It is important to remember not everyone will have a problem with every FODMAP. Some people might have symptoms triggered by one or two types of FODMAPs, whereas others may be sensitive to all five.  The reasons for this are unknown, but foods should only be restricted if they contribute to symptoms. The diet is intended to be individualised according to the problematic FODMAP, so it is very important to seek guidance from a dietitian.

High FODMAP foods

This is not a definitive list – please refer to your dietitian or healthcare provider for more information.

Examples of foods containing fructans

  • Wheat
  • Rye
  • Barley
  • Garlic
  • Leek
  • Onion
  • Lentils
  • Chickpeas
  • Legumes
  • Cashews
  • Pistachios

Examples of foods containing galacto-oligosaccharides

  • Baked beans
  • Lentils
  • Borlotti beans
  • Chickpeas
  • Soybeans
  • Kidney beans

Examples of foods containing lactose

  • Animal milks
  • Custard
  • Ice cream
  • Condensed milk
  • Evaporated milk
  • Yogurt
  • Dairy desserts

Examples of foods containing excess fructose

  • Apples
  • Pears
  • Mangoes
  • Watermelon
  • High-fructose corn syrup
  • Honey

Examples of foods containing polyols

  • Nectarines
  • Peaches
  • Plums
  • Cauliflower
  • Mushrooms
  • Sugar snaps
  • Chewing gum
  • Confectionery with polyols

The expert verdict

Does it really work? If IBS is a confirmed diagnosis, the low FODMAP diet can be extremely effective. It is heavily supported by science and if followed correctly, has proven to be effective in significantly reducing symptoms. It can be a challenge to follow at times, but the efforts are well worth the rewards. I tell my clients planning and preparation are key to success.

A word of advice, if you suspect you suffer from IBS, speak with your GP. It is important to exclude coeliac disease and other possible medical conditions first. If IBS is confirmed as the cause of symptoms, then a low FODMAP diet under guidance with a dietitian can definitely be beneficial.

Low FODMAP recipes to try...

Salmon & lemon mini fishcakes
Baked sea bass with lemon caper dressing
Potato salad with anchovies & quail's eggs
Chocolate crunch & raspberry pots
Gluten-free carrot cake

For more tempting ideas, visit our low FODMAP diet recipe collection.

Emer Delaney BSc (Hons), RD has an honours degree in Human Nutrition and Dietetics from the University of Ulster. She has worked as a dietitian in some of London's top teaching hospitals and is currently based in Chelsea.

This article was reviewed on 8 August 2018 by nutritionist Kerry Torrens.

Kerry Torrens is a qualified Nutritionist (MBANT) with a post graduate diploma in Personalised Nutrition & Nutritional Therapy. She is a member of the British Association for Nutrition and Lifestyle Medicine (BANT) and a member of the Guild of Food Writers. Over the last 15 years she has been a contributing author to a number of nutritional and cookery publications including BBC Good Food.

All health content on bbcgoodfood.com is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other healthcare professional. If you have any concerns about your general health, you should contact your local healthcare provider. See our website terms and conditions for more information.

Have you tried a low FODMAP diet? Share your stories below...

Comments, questions and tips

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27th Jul, 2019
This diet really helped with my IBS. Nightmare finding garlic and onion free items in the supermarket.., but found a site called Fodmap Foods Co where I buy my essentials. Starting is the worst bit because you need to learn to cook and flavour dishes while being limited by ingredients. You learn as you go though.
27th Apr, 2017
When I was diagnosed with Ulcerative Colitis my then Consultant told me that many people had found it helpful to add FructoOligosaccharies to their diet, along with a source of Probiotics. Personally I find that too much fresh fruit, any dairy and always Cauliflower cause upsets but Goats milk or Goats Cheese doesn't
26th Apr, 2017
I went on the FODMAP diet after years and years of IBS - and it worked.
6th Apr, 2016
I have fructose intolerance and tried the FODMAP diet. Not much help but by cutting out fructose and just eating a bit if I have to I am now fine so long as I stick to it! Wish someone would bring out a cookery book with fructose free recipes. I was told that there are over 22 million books in the British Library and not one about fructose intolerance! Everything's gluten free and lactose free etc but we are in a minority. Fingers crossed.
16th Oct, 2017
I have also found the quit plan was useful reference in general as it went through the fructose content of a lot common foods and also the sweeteners and more complex sugars that are broken down by the body into fructose components.
16th Oct, 2017
I found the recipes at the back of Sweet Poison (Quit Plan) by David Gillespie have worked well (he has focused on foods that usually contain lots of sugar). I tried the banana muffins out weekend just gone and they got the approval from hubby. The fructose was subbed out for Dextrose. I have noticed he has now got a specific cook book out to I might treat myself to. I Think it is called the No Recipe Cookbook
27th Apr, 2017
Sorry, the formatting on this site has screwed up my Reply!! There are three Links, the first ends 'WssHRQ', the second starting 'Fructose friendly chef' and ending '_mlt4997A' and the third starts '100 Fructose Free Recipes' and ends BICM3g7g'. By Copying and Pasting each into your Search engine they should work.
26th Nov, 2015
The low FODMAP diet changed my life and dramatically reduced my IBS symptoms. It is a huge learning curve and can be very daunting when you first start. I am now helping other FODMAPers by providing delicious low FODMAP recipes and up-to-date information on the diet through my website www.alittlebityummy.com I also work closely with Monash University who are the lead researchers of the diet. I hope this article encourages other IBS sufferers to try the diet and gain good symptom control!
25th Nov, 2015
I was suffering quite badly with IBS, feeling incredibly bloated and gassy(!). It was awful and I was in huge amounts of pain and often after eating I would feel like I had large bubbles exploding in my stomach. I found the FODMAP diet online and cut out the foods required. After a few months of bliss where I was symptom free, I have gradually been able to introduce all of the foods back in, sometimes in small doses only though with things such as beans and lentils. I would definately recommend giving it a go!
3rd Mar, 2018
I have to have a gluten and dairy Fidmap diet. Have you got any good pastry (sweet & savoury), bread roll and cake recipes please?
goodfoodteam's picture
7th Mar, 2018
Thanks for your question. We have a variety of recipes in the following collection. You will need to check the ingredients to make sure they are appropriate for you as they may contain gluten or dairy: https://www.bbcgoodfood.com/recipes/collection/low-fodmap. We also have specific gluten-free and dairy-free recipe collections but these are not designed with FODMAP in mind so again, please check for suitability: https://www.bbcgoodfood.com/recipes/collection/gluten-free https://www.bbcgoodfood.com/recipes/collection/dairy-free
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