The low-FODMAP diet for IBS

Senior Dietitian, Bupa Cromwell Hospital
24 March 2017

Many people find that following the low-FODMAP diet helps with the symptoms of irritable bowel syndrome (IBS). But it’s not a do-it-yourself diet, and guidance from a suitably qualified dietitian is essential.

Here I explain what the diet is, what you should do before considering it, and what the diet involves.

Image showing some garden vegetables on a bench

Living with IBS

The symptoms of IBS, such as abdominal (tummy) pain, bloating, constipation and diarrhoea can make everyday life a misery. Many people with IBS notice that these symptoms get worse after eating.

There’s a lot you can do to manage IBS. For example, reducing stress and staying physically active can be helpful. Medication can also help some people. Adjusting your diet is another important action you can take.

What to do first

The low-FODMAP diet, which limits your intake of certain carbohydrates, can be effective in reducing IBS symptoms. But it is not the place to start.

First, you have to get the basics right. This means ensuring you already have a generally healthy, balanced diet. Then it’s time to look at your intake of known triggers for IBS symptoms. These include alcohol, caffeine, spicy foods and fat. If symptoms continue, you could consider restricting milk and dairy foods, or the amount and type of fibre you eat.

If you’re still having trouble after these adjustments, it may be worth considering a low-FODMAP diet.

Working with your dietitian

It’s so important to work with a dietitian who is trained in the details of this diet. There are a few reasons for this. The diet can be complicated to follow. And, it removes so many foods from your daily intake, there is a risk of missing out on important nutrients, or not sticking with it. Fortunately, it’s not a diet for life: you only follow it for a few weeks.

What does FODMAP stand for?

  • Fermentable (meaning that gut bacteria break down the nutrients, producing gas)
  • Oligosaccharides (complex carbohydrates)
  • Disaccharides (double-unit sugars)
  • Mono-saccharides (single-unit sugars)
  • Polyols (sugars found in some fruits and vegetables, and in artificial sweeteners)

How the low-FODMAP diet might work

There’s still some debate about whether the low-FODMAP diet has been thoroughly proven. However, there is some evidence that the low-FODMAP diet can help people with IBS. For example, in one UK study, 76 per cent of people participants on the low-FODMAP diet said they were satisfied with the improvements to their symptoms. In the same study, only 54 per cent of those following conventional IBS dietary advice were satisfied with the improvement in their symptoms.

The diet is thought to work by reducing a process called fermentation in the gut. Fermentation happens when naturally occurring gut bacteria break down certain foods and produce gases such as carbon dioxide, hydrogen and methane as by-products.

High-FODMAP foods

Here are some of the foods that are avoided on a low-FODMAP diet. Please talk to your dietitian before eliminating these foods:

  • wheat
  • rye
  • onions
  • garlic
  • pulses (for example, beans and lentils)
  • milk and dairy foods
  • certain fruits, including apples and pears
  • certain vegetables
  • honey, plus some other natural and artificial sweeteners

This diet is not for everyone, but it helps to remember that this is just one of many choices that can help ease IBS symptoms. If you are struggling with such symptoms, please do talk to a registered dietitian with experience in this area. You might find it’s one of the best things you’ve ever done for yourself.

Shweta Bhasin
Senior Dietitian, Bupa Cromwell Hospital

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