A low FODMAP diet reduces or removes certain foods from the diet. It can help some people avoid abdominal (tummy) pain and discomfort.

What is a low FODMAP diet?

FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols. These are the chemical names of several sugars that are poorly absorbed in the small intestine.

The sugars can trigger symptoms of Irritable Bowel Syndrome (IBS) in some people, such as diarrhoea, flatulence (passing wind), abdominal bloating, pain, nausea and constipation. These symptoms can affect people’s lives and make them feel uncomfortable, causing stress and embarrassment.

A low FODMAP diet reduces or removes certain everyday foods that are high in FODMAPs. These include some grains, vegetables, fruits and dairy products.

How was the low FODMAP diet developed?

The low FODMAP diet was developed by researchers at Monash University in Victoria to help people with IBS control their symptoms. FODMAPs don’t cause IBS to develop; however, they can trigger the symptoms of IBS in those people who have it. Monash University researchers identified which foods are low and high in FODMAPs to help people with IBS identify which foods they should eat or avoid.

What foods should be avoided?

A range of foods are high in FODMAPs, including:

• garlic
• onions
• apples
• green peas
• some marinated meats
• dairy products (e.g. milk, yoghurt)
• chickpeas
• wheat, barley and rye-based bread

People who have symptoms of IBS may find it helpful to avoid high FODMAP foods and instead, to eat a diet containing a low volume of FODMAPs. Low FODMAP foods include:

• red capsicum
• oranges
• grapes
• eggs
• plain cooked meat
• oats
• rice
• dark chocolate
• peanuts

For a list of high and low FODMAP foods, visit the Monash University FODMAP website.

Who should advise on a low FODMAP diet?

If you are considering a low FODMAP diet, you should consult a registered dietitian. They will advise you on which foods to eat and to avoid and will also help you reintroduce certain foods back into your diet so you can be clearer about which foods trigger your IBS.

A low FODMAP diet is not a lifetime diet. It is usually recommended for 2 to 6 weeks at a time, until the IBS symptoms have got better. Once certain foods have been reintroduced again, some people find that they simply need to avoid some high FODMAP foods.

Possible adverse effects of low FODMAP diets

Because there is a wide range of foods to avoid, it’s important that your dietitian helps you to ensure you still get adequate nutrients. You may need to take vitamin and mineral supplements.

There is also a risk that your fibre and calcium intake will drop too much if you don’t find a suitable low FODMAP substitute.

What if a low FODMAP diet doesn't suit me?

Before you begin a low FODMAP diet, you should work with your doctor to make sure that what you have is IBS, not another condition such as inflammatory bowel disease, coeliac disease or bowel cancer.

Sometimes, IBS symptoms can be triggered by things other than FODMAPs in the diet — such as high fat, spicy foods or caffeine. Stress can also be a trigger. Your dietitian can help you identify if these other things are an issue and also advise you if a low FODMAP diet is not suitable for you.

More information

For more information about a low FODMAP diet:

• Visit the Monash University FODMAP website
• Contact an accredited practising dietitian
• Visit your doctor

Check your symptoms with healthdirect’s Symptom Checker to get advice on when to seek medical attention.