What does FODMAP stand for?

FODMAP is an acronym that describes the short-chain carbohydrates that are poorly digested by humans:

Fermentable

This refers to the process through which gut bacteria degrade undigested carbohydrates to produce gases including hydrogen, methane and carbon dioxide. FODMAPs pull more water into the gut to get broken down by bacteria in a process called ‘fermentation’. This produces more gas in your intestines and can cause discomfort.

Oligosaccharides 
Oligosaccharides are made of fructans and galacto-oligosaccharides (GOS). Fructans are found in foods like wheat, rye, onion and garlic and galacto-oligosaccharides (GOS) are found in legumes and pulses. They are poorly absorbed by people and can trigger gastrointestinal upset.

Disaccharides 
This refers to carbohydrates composed of two sugars (called ‘monosaccharides’). Lactose is a common disaccharide found in dairy products like milk, soft cheese and yoghurt. Many people are intolerant to lactose because they don’t have the lactase enzyme present in their gut to help break it down.

Monosaccharides
Monosaccharides include simple sugars such as fructose and glucose. Fructose is absorbed optimally in the presence of enough glucose. Consuming foods that are high in fructose but low in glucose (for example, honey, apples and high-fructose corn syrups) can cause fructose malabsorption.

Polyols 
Polyols are sugar alcohols (for example, sorbitol and mannitol) that are found in some fruits and vegetables. They are often extracted and used as artificial sweeteners.

What happens when FODMAPs are consumed?

FODMAPs are rapidly fermented by the bacteria living in your intestines. They pull more water into your gut, which can cause more gas to be produced. This results in bloating and distension, impacting the ways the muscles in your gut contract. As a result, people with irritable bowel syndrome (IBS) can experience gastrointestinal discomfort (such as diarrhea and constipation). People without IBS are typically able to ingest FODMAPs without concern.

Low FODMAP Diet FAQs

Does cooking break down FODMAPs in a way that would make them easier to digest?

We have found that canning and preserving food under acidic conditions (processes like pickling, for example) had the most dramatic effect on FODMAP content in foods. In canned legumes (lentils and chickpeas) the water-soluble FODMAPs (GOS) leach out of the legume into the brine mixture. So, if you’re eating a low FODMAP diet, make sure that you discard the brine and wash your legumes before use.

For pickled artichokes, the combination of acid (from the vinegar) and the leaching out of FODMAPs greatly lowered the fructan (a poorly absorbed carbohydrate which falls under the FODMAP umbrella) content of the artichokes.

While it’s also possible that very high temperatures may also break down FODMAPs, we have found that the extent of this reaction can vary greatly depending on the food being cooked, the temperatures used as well as other cooking conditions. In other words, it is harder to predict how effective the cooking has been in lowering the FODMAP content in food. We currently can't recommend the use of cooking to lower FODMAP levels in a meal because more research is required in this area. At present, the most reliable approach is to use low FODMAP ingredients in your cooking.

How can I add flavor to food without onion or garlic?

Garlic and onions are very high in the FODMAP fructan and so, are not suitable on the Low FODMAP Diet. However, it is possible to add some flavour from onions and garlic into your cooking.

FODMAPs are not soluble in oil, so a great way to add flavour back to your foods is to use garlic-infused oil. This can be done by sautéing whole garlic pieces (that is, not smashed or finely chopped) in oil for 1-2 minutes to develop the flavor in the oil. Remove and discard the garlic afterwards, as the clove itself will still be high in FODMAPs.

If you’d like to learn more about creating delicious, low FODMAP meals, we’ve included a large number of delicious and nutritious recipes to the FODMAP App.

What should I do if low FODMAP fruits still cause gut symptoms?

Avoid large servings of any fruit and be particularly careful to limit fruit juice and dried fruit to safe quantities. All fruits that we have found to be low FODMAP should be tolerated by most people with IBS at the serving sizes specified in the FODMAP App.

There are also other dietary components that can induce various reactions (including gut symptoms) in a small number of people. If you are not experiencing relief despite following our suggestions, we recommend you consult a dietitian with experience in food intolerances.

Why are some dried fruits listed as high FODMAP when the fresh fruit equivalent is low FODMAP?

Preparation of dried fruit requires dehydrating the fresh fruit to remove the water. This process concentrates all sugars (and therefore the FODMAPs) that were present in the fresh fruit initially. We have also detected fructans in dried fruit that are not present in the same fresh fruit.

Dried fruit tends to shrink substantially compared to their original size when fresh. As a result, it can be easy to consume more fruit without realizing it! That’s why serving sizes are so important. We advise checking the FODMAP App for appropriate servings for each type of dried fruit rather than relying only on the overall “traffic light” rating.

Some dried fruits (cranberries for example) are only high in FODMAPs if consumed in larger serving sizes. Smaller servings are of dried cranberries are low in FODMAPs and should be tolerated by most people with IBS.

Does the process of making sourdough bread improve the digestion of grains?

We know that the levels of FODMAPs (specifically fructans) are reduced during the sourdough fermentation process. It appears that fructans are used by the yeasts and lactobacilli during fermentation. Therefore, certain traditionally-fermented sourdough breads (made from lower FODMAP flours such as spelt and oat) are classed as low or moderate in FODMAP content. 

However, some sourdough breads made from high FODMAP flours (such as wheat and rye) still tend to be high in FODMAPs. The best approach is to ask your baker which flours they use, how the bread is prepared and if traditional sourdough techniques have been used (i.e. an overnight proving).

Because the foods listed in the Monash FODMAP App are an average of a number of products that have been tested, we are unable to name brands of bread in the app. Some bakeries, however, are now part of the Monash University Low FODMAP Certification program – which means we have tested their products and the companies have agreed not to change their recipe. These certified products are named in the app under ‘Low FODMAP Certified Foods’ in the Food Guide section.

What’s better for digestion? Eating larger meals, more spaced out meals or smaller, more frequent meals?

In line with general dietary guidelines, we suggest eating three main meals per day plus one or two snacks between meals if required. Check our dietary guide for information about serving sizes for adequate nutrition.

If you are hungry, try including another type of low FODMAP food or perhaps consume a larger serve of a low FODMAP food (if appropriate). Serving size does significantly affect the FODMAP rating of some foods.

If you have additional dietary considerations we recommend speaking with your dietitian to create a unique eating plan for your body.

Are fats and oils high in FODMAPS? Is there a difference between oils like olive oil and coconut oil?

Fats and oils are generally low in FODMAPs as they contain very little or no carbohydrates. However, it is important to note that fats and oils do affect gut motility and, when consumed in excess, can also trigger gut symptoms in some people.

Also, be aware of oil-based sauces and condiments (such as salad dressings and aioli) as these may contain high FODMAP ingredients such as garlic. Check the ingredients list of these products before consumption.

For general good health and to reduce the risk of chronic disease, the current Australian Dietary Guidelines recommends limiting the intake of fats and oils that are high in saturated fat (such as butter, palm oil and coconut oil).

Are meats low in FODMAPs?

Sources of animal protein such as meat, chicken, fish and eggs are generally low in FODMAPs as they contain very little or no carbohydrate. However, beware of potential high FODMAP ingredients added in the preparation of these foods such as bread crumbs, onions, garlic, marinades and sauces or gravies.Sources of animal protein such as meat, chicken, fish and eggs are generally low in FODMAPs as they contain very little or no carbohydrate. However, beware of potential high FODMAP ingredients added in the preparation of these foods such as breadcrumbs, onions, garlic, marinades and sauces/gravies.

What is ‘Low Glycemic Index’ and why should Low GI wines be avoided under the Low FODMAP Diet?

Glycemic Index (GI) is a rating applied to carbohydrate-containing foods according to how much they raise blood glucose levels after eating. Low GI foods are slowly digested and absorbed and therefore result in a gradual rise in blood glucose levels compared to high GI foods. We found that low GI wine is high in fructose, so its consumption should be avoided under the Low FODMAP Diet.

For more information on GI, take a look at the University of Sydney’s research.

Which cheeses contain FODMAPs?

The FODMAP contained in many dairy products is called ‘lactose’. Generally speaking, hard cheeses and other matured or 'ripened' cheeses (such as brie, camembert and feta cheese) are low in lactose or are even lactose-free. Cheeses that contain moderate amounts of lactose are cream cheese, ricotta cheese and haloumi cheese. Low FODMAP serving sizes are provided for ricotta and haloumi cheese in the FODMAP App. However, it’s best to check with your dietitian about testing for lactose malabsorption. If you’re not lactose intolerant, you should be able to eat low FODMAP dairy products.

Where can I find a specialist dietitian?

Dietary restriction of poorly absorbed FODMAPs is a specialized area of nutrition. We highly recommend that individuals with Irritable Bowel Syndrome (IBS) or Functional Gastrointestinal (FG) disorders seek the guidance of a dietitian with experience in this area.

We recommend that the Low FODMAP diet is trialed for 2-6 weeks followed by review. Your dietitian will guide the re-introduction of FODMAP-containing foods (which foods and how much) back into your diet. We recommend you search for accredited or registered specialist gastrointestinal dietitians through the official association in their country of practice:

Australia

Find an Accredited Practising Dietitian (APD) at Dietitians Association of Australia (select ‘gastrointestinal (bowel and stomach disorders’ in the dropdown menu).

Canada

Find a qualified nutrition professional from Dieticians of Canada.

USA

Find a registered dietitian from the Academy of Nutrition and Dietetics.

UK

Find FODMAP-trained dietitians from Kings College London or check the NHS website for more options.

Is there anything else that can improve the absorption of FODMAPs?

Fructose (monosaccharides)

When it comes to absorbing fructose, it’s common belief that adding glucose can aid absorption, however our recent research does not indicate this. We recommend that you review our app to check the FODMAP levels of foods and adhere to our recommendations on how much of them to consume.

Lactose (disaccharides)

Lactase enzyme products may be worth trialing if you have lactose malabsorption. Available from pharmacies as drops or tablets, they can be used to break down the FODMAP, lactose, which is present in milk and other dairy foods.

Oligosaccharides

We have recently published research indicating that the enzyme 'alpha-galactosidase' may assist in the digestion of foods high in the FODMAP galacto-oligosaccharides (GOS). These enzyme supplements may be particularly useful for vegetarians and vegans following a low FODMAP diet who rely on legumes (generally high in GOS) as a key protein source.

How much sucrose (table sugar) can I have under the Low FODMAP Diet?

Sucrose is a disaccharide (a sugar composed of two units) made up of equal parts glucose and fructose. Sucrose is broken down and absorbed efficiently in the small intestine. Small amounts (around one or two teaspoons in a hot drink or a small handful of candy) are usually well tolerated. For some people with IBS, large amounts of sucrose may be poorly tolerated and so it is best to limit large doses.

What happens if I break the diet?

The main aim of a low FODMAP diet is to achieve good symptom control and to reintroduce FODMAPs slowly back into your diet in quantities that your individual system can tolerate.

Occasional intake of FODMAPs may not induce symptoms when the overall load of FODMAPs is reduced. If you do experience gastrointestinal symptoms because you’ve consumed too many FODMAPs, return to a strict low FODMAP diet and symptoms should improve within one to three days.

Is this the Low FODMAP Diet for life?

No, the aim of the Low FODMAP Diet is to heal your gut and to reintroduce certain foods back into your diet over a controlled period of time. It is recommended that the Low FODMAP Diet is only followed for 2-6 weeks. Then your progress should be reviewed by your dietitian, who will advise which foods (and how much of them) can be gradually added to your diet. Diets should be tailored for each individual’s needs.

After the initial restrictive diet, many people are able to return to their usual eating habits, with just a few high FODMAP foods that need to be avoided in large amounts. Recent research has shown that following a strict low FODMAP diet in the longer term can reduce levels of certain beneficial bacteria in the gut. For this reason, we recommend your don’t follow an unnecessarily strict low FODMAP diet and to see a specialist dietitian for appropriate reintroduction of FODMAP-containing foods.

What is the difference between 'gluten-free' and 'wheat-free' foods? Do I have to restrict gluten under a low FODMAP diet?

A strict, life-long ‘gluten-free’ diet is only recommended to those diagnosed with coeliac disease. Coeliac disease is an autoimmune condition that results in the inflammation of the small intestine when any gluten is ingested. Ensure that you are properly assessed for coeliac disease before removing gluten entirely from your diet.

When following the Low FODMAP Diet, fructans and other FODMAPs, are restricted. Gluten is the protein found in wheat, rye, barley, and some oats. These cereals also happen to be high in FODMAPs (mostly fructans). ‘Gluten-free’ foods are commonly made from rice flour, maize or corn flour, potato flour and quinoa, which are low in FODMAPs. By choosing ‘gluten-free’ you may also be choosing low FODMAP. Keep in mind, ‘gluten-free’ foods can also have high FODMAP ingredients like onion, pear or honey added, so make sure you check the ingredients carefully.

Choosing a strict gluten-free diet when you only require a low FODMAP diet can lead to over-restriction. For example, oats and spelt bread contain gluten but are relatively low in FODMAPs so are suitable to have on a low FODMAP diet in appropriate servings. In addition, gluten is found in products derived from wheat, rye and barley, such as wheat starch, wheat thickeners and barley malt. These are common ingredients in a wide range of commercial products including soy sauce, confectionary, mayonnaise, yoghurts and more. They contain gluten and must be avoided on a gluten free diet for coeliac disease, but they are not high in fructans and are suitable to include in a low FODMAP diet. 

‘Wheat-free’ refers to any food that does not use wheat during its manufacturing process. But, ‘wheat-free’ foods may still include ‘gluten-containing’ cereals such as rye, barley, oats, spelt and ‘fructan-containing’ cereals like rye and barley. That means that wheat-free products are not necessarily low in FODMAPs and products claiming to be wheat free should be checked for other FODMAP-containing ingredients.

IBS FAQs

I have been diagnosed with ‘fructose malabsorption’; do I need to restrict fructose and other FODMAPs in my diet?

Fructose malabsorption is fairly common and FODMAPs only need to be restricted if they induce undesirable gastrointestinal symptoms such as diarrhoea or constipation. We highly recommend that you see a dietitian with experience in this area. They will guide you through appropriate exclusion of FODMAPs followed by a structured re-introduction of FODMAPs back into your diet. You may find that after the diet, you can tolerate small amounts of excess fructose (and other FODMAPs) without exacerbating your symptoms.


I was tested for fructose and lactose malabsorption and my breath test results were negative. Does this mean the diet can’t help me to control my IBS?

Cutting out FODMAPs in your diet, even if you’re not especially intolerant, can help alleviate your IBS symptoms. That’s because our research has found that FODMAPs are poorly absorbed in everyone, which means that lactose and fructose are particularly triggering to people with IBS.

What is the association between parasites, gastroenteritis and IBS?

Cryptosporidiosis is a type of gastroenteritis that is caused by a gut parasite called cryptosporidium. There is evidence that up to a third of people who suffer a bout of gastroenteritis go on to develop ongoing gut symptoms known as post-infectious irritable bowel syndrome (PI-IBS).

The risk of developing PI-IBS increases if the bout of gastroenteritis beforehand is particularly severe or long-lasting. It is thought that gastroenteritis can change the type and amount of bacteria in the gut, which can cause ongoing inflammation and damage to the lining of the gut.

Are there other strategies to manage IBS (for example, probiotics)?

Probiotics are live microorganisms that can lead to health benefits in the gut. There is some evidence that probiotics can help with IBS symptoms, but this may vary depending on which probiotic preparation is used. 

We recommend that you try one management strategy at a time; commence the low FODMAP diet first. If you have not achieved good symptom control after two to six weeks, consult with your dietitian. At this review-stage, you can discuss other management strategies and the possibility of introducing probiotics.

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