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.


Discover our full range of health benefit guides and read more about popular diets such as the sirtfood diet and IBS diet. Also check out some of our delicious low FODMAP recipes, from baked sea bass to gluten-free Yorkshire puddings.

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.


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