The Low FODMAP diet



Why not start with this 60 second explainer video from the founders of the low FODMAP movement, Monash University.


Who is the low FODMAP diet for?

The low FODMAP diet can potentially help anyone having symptoms of gastrointestinal distress such as bloating, nausea, cramps, diarrhoea, constipation, acid reflux, and heartburn.  If you have any symptoms such as blood in your stool, sudden and sustained diarrhoea, fever, anemia, weight loss, or if you are over 60, you should go to your doctor as soon as possible.

People with IBS will definitely benefit from following the low FODMAP diet.  For those with IBD, SIBO, leaky gut syndrome, candidiasis and other bowel issues, the low FODMAP diet along with additional support is recommended.  You may of course still find it helps you even if you aren't diagnosed with any specific problems.

The low FODMAP diet may not be suitable for those who are at risk of malnutrition, those prone to disordered eating, or those who can not purchase or prepare their own food. It is always recommended that you talk to your doctor or a FODMAP trained dietitian before starting a new diet to help keep you safe and to make sure that you have sound and trustworthy information and advice that's right for you.


Can I get a test for FODMAPs?

There are no medical or lab tests that can tell you if you're sensitive to FODMAPS, so the only way to find out is to try the diet.  Keeping a food journal can help you to spot patterns in your symptoms and make links with the foods you ate, and can make it much easier for your health professional to indentify the root cause of your symptoms.


What are FODMAPs?

FODMAPs are sugars, short-chain carbohydrates, that can be fermented in the gut.  FODMAPs are not of themselves harmful, but some people have difficulty digesting them which can lead to symptoms such as bloating, nausea, cramps, and diarrhoea.

Some FODMAPs are naturally occurring and are found in lots of different fruits, vegetables, dairy, and grains.  FODMAPs can also be added to foods and are found in a wide variety of processed and prepared foods.

Because all FODMAPs are sugars and therefore carbohydrates, this means that proteins and fats are all zero-FODMAP.  While all FODMAPs are carbohydrates, not all carbohydrates are FODMAPs, and carbohydrates are still an essential part of a balanced diet.  Most foods contain mixtures of proteins, fats, non-FODMAP carbohydrates, and FODMAPs, so you'll need to get to know which foods work for you and which don't.  This is what the low FODMAP diet aims to help you with.


Who invented FODMAPs?

FODMAPs have always been around in foods, but their effects have only recently been understood.

In the early 2000s a team of researchers at Monash University in Australia identified them as being linked to symptoms of gastrointestinal distress.  They coined the acronym FODMAP because there was no other common term that described this group of short-chain carbohydrates.  You can read more about Monash University and their pioneering research on their website.


What does FODMAP stand for?

The acronym lists the different types of problematic carbohydrates:


Here's a breakdown of what each of these terms actually means:


When the bacteria in your gut feed on FODMAPs they create chemical and gaseous byproducts, leaving you feeling sick and bloated.

Oligosaccharides (OS), Galacto-oligosaccharides (GOS), Polysaccharides

This means sugars linked in chains.  The key culprits in this group are:

Fructan (3-10 linked Fructose units)

Inulin (more than 10 Fructose units)


Lactose is the only problematic disaccharide, found in many (but not all) dairy products. 

Sucrose (aka ordinary sugar) is a disaccharide made of a fructose molecule linked to a glucose molecule, but your gut is able to digest sucrose because of a phenomenon called fructose piggybacking.


This means fructose, often described as "excess fructose".

Fructose can be absorbed in the gut if it can find a glucose molecule on which to hitch a lift, called piggybacking.  If there is more fructose than glucose (excess fructose) then this becomes fermentable.



These sugar alcohols include Erythritol, Inositol, Isomalt, Maltitol, Mannitol, Sorbitol, Xylitol.

NB Erythritol, the smallest polyol, is not generally considered a FODMAP because most people are able to digest and absorb it sufficiently, but some sensitive individuals may wish to avoid it.


How do I know if something is a FODMAP or not?

The only way to determine a food's FODMAP content is through lab testing.  The two main companies are Fodmap Friendly and Monash University, both based in Australia.

Monash University's data is available to browse through their smartphone app and can help you learn about the FODMAP content and appropriate portion sizes for many foods.  Fodmap Friendly has a handy chatbot that you can interact with through Facebook messenger; for each ingredient you ask it, it will reply with whether it is high or low FODMAP.

Neither the app nor the chatbot has information for many processed or packaged foods, especially not UK ones, but you can look up the ingredients for recipes or products, and if those are low in FODMAPs (or present in acceptable amounts) then you can be reasonably sure that the recipe or product as a whole will also be low FODMAP.  Remember that the presence of high FODMAP ingredients does not mean something is high FODMAP if they are only present in small amounts.

Constantly looking up ingredients can be time consuming at first, but before long you will start to remember things and need to look them up much less frequently.

A FODMAP qualified dietitian can also help you select foods suited to your lifestyle and tastes and ensure that your diet is varied and provides optimal nutrition.


What is the low FODMAP diet?

The low FODMAP diet is a plan devised by scientists at Monash University to help people control and manage symptoms of gastrointestinal distress such as bloating, nausea, cramps, constipation, and diarrhoea.

The diet has three phases.  Some people do the process once and then find their new normal, while others feel they benefit from repeating the process every now and again; everybody is different, and our microbiome is always changing.   It is always recommended that you talk to your doctor or a FODMAP trained dietitian before starting a new diet.





4-6 weeks

Cut out all FODMAPs.  This allows your gut to calm down and your symptoms to subside.  Top tip: get in the habit of reading and checking absolutely all the ingredients on everything.


As required

Reintroduce FODMAPs one at a time, starting with small portions and gradually increasing over a few days.  A FODMAP qualified dietitian will have a protocol for you to reintroduce foods in appropriate incremental amounts, and apps like Monash University's can help you identify the FODMAP content of foods that you want to reintroduce.

The aim here is to test your body's response, to learn which FODMAPs trigger your symptoms, and what levels of each FODMAP you can tolerate.  This is different for everyone and may also change over time.

It is recommended you keep a journal of this phase to help you identify patterns since symptoms from consuming a portion of a FODMAP can take up to several hours to manifest and may last for up to 72 hours.



By now you will have a good idea which foods you can eat freely, which foods are ok in moderation, and which foods are best avoided.

Try to eat as wide a variety of foods as you can, including whatever amounts of FODMAP-containing foods that are safe for you.  This is because while foods that are high in FODMAPs can cause problems if you eat them too much or too often, they also tend to have lots of other great nutrients.

Just remember to keep reading all those labels, and be careful of stacking!


Are FODMAPs dangerous?

No, FODMAPs are not dangerous at all.  All FODMAPs are carbohydrates, and carbohydrates are essential as part of a balanced diet.  FODMAPs can become problematic if you have difficulty breaking them down and digesting them as they may be fermented by bacteria, but they don't pose any further risk than that.


Many foods that contain FODMAPs also contain other beneficial nutrients.  For this reason the diet aims to help you learn which FODMAPs you can tolerate and in what amounts, so that you can continue to enjoy as varied and nutritious a diet as possible.  Just remember to be careful of stacking.

It's a good idea to talk to your doctor or FODMAP qualified dietitian before starting a new diet.


What is stacking?

Stacking is when you consume multiple servings of FODMAPs and the effects in your gut accumulate over anywhere between 24 and 72 hours.  This is because it takes time for FODMAPs to pass through your system.  Stacking can apply to multiple FODMAP serves in a single meal, as well as to servings spread across the day.

It may help to think of it like a daily budget: the more sensitive you are to any given category of FODMAPs, the less credit you have to spend in that category each day.  If you max out your budget in one day you might try to stay below the limits the next day.  If you are sensitive to multiple categories of FODMAPs it may help to avoid pushing your limits in multiple categories in the same meal.  Remember that the effects are cumulative, that's why it's called stacking.


Should I avoid FODMAPs forever?

Ideally no.  You should avoid FODMAPs during the elimination phase of the diet.  Reducing the FODMAP load will allow your symptoms to subside.  After that the goal is to find out exactly which ones affect you and how much you can tolerate of them.  This will allow you to eat as wide a variety of food and nutrients as possible while still keeping your symptoms under control.  With a qualified dietitian's help you can often resolve symptoms completely by finding and treating the root cause of dysbiosis.


Why aren't FODMAPs a thing for everyone?

Your gut contains a whole host of bacteria called your microbiome.  It is estimated that in a 70kg individual there 100 trillion microorganisms weighing a total of about 200g.  These bacteria play an important role in the digestive process, helping to break down your food in to nutrients that your body can absorb.

Natural variation in the microbiome can lead to people have varying degrees of success in breaking down different foods, as can changes in bacteria due to illness, antibiotic use, and stress.  For some people the undigested elements of their food pass through with no symptoms.  For others they can become fermented by bacteria, leading to symptoms such as bloating, nausea, cramps, and diarrhoea.

There is emerging research about why microbiomes vary from person to person, but more needs to be done.  For now the best way to manage your symptoms is by learning which foods work for you.


Is gluten a FODMAP?

No, gluten is a protein so is not a FODMAP.  You need to avoid gluten strictly if you are coeliac or if you have non-coeliac gluten sensitivity.  Even though gluten itself is not a FODMAP, many foods that contain gluten are also high in FODMAP carbohydrates.  This is why it is important to avoid wheat, rye, barley, amaranth, and freekeh during the elimination phase.

The free from aisle is a good place to start when looking for low FODMAP options, but be warned that many gluten-free products have high FODMAP additives such as apple, amaranth, soya, or pea.  Remember to always read the label.


What do the different logos on your products mean?

Certified low FODMAP logos:

Fodmap Friendly

Monash University

Fodmap Friendly and Monash University are the two independent bodies that test and certify products as low FODMAP.  If you see either of their logos on a product it means you can buy with confidence knowing that it has been lab tested and approved as low FODMAP.

Certified gluten free logos:

Some products also carry a gluten free certification mark.  Following a strict gluten free diet is the only available treatment for coeliac disease.  If you are coeliac it is advised that you only buy products that are certified gluten free.  If you are low FODMAP, the gluten free mark guarantees the absence of wheat, barley, rye, and other gluten-containing ingredients, but there may still be other high FODMAP ingredients present so always check the label.


Do I need to go low FODMAP forever?  Can I be cured?

Low FODMAP forever is not recommended because restricting for too long and reduce your gut bacteria diversity.  Restricting is only recommended for a short period of time (up to two months) to allow symptoms to subside.  The aim of the low FODMAP diet is to help you learn new long-term dietary habits to prevent symptoms of gastrointestinal distress.  The foods that you can and can not tolerate may change over time, and will be different from person to person.

Some people find that they need to avoid FODMAPs to a greater or lesser extent on an ongoing basis after doing the elimination phase, though most find that they are only sensitive to one or two types of FODMAPs.  If you are struggling then you should get professional advice from a FODMAP trained dietitian.

Whatever works for you, Fodpod is here to support you through your journey with information and products that you can trust.


How come some certified low-FODMAP products contain high FODMAP ingredients?

It's all about portion sizing.  The smaller the quantity that is present of a high FODMAP ingredient, the less it will contribute to the overall FODMAP content of the product. Products are only certified low FODMAP if the total levels of fructan, lactose, sorbitol, mannitol etc. are tested and fall below what is considered safe.  That said, if you know that you are highly sensitive (or allergic) to a specific ingredient then you may still wish to avoid products that contain it.  Always read the label.


What foods can I eat?

At Fodpod all our products have been carefully selected for their compatibility with the low FODMAP diet so that you can shop in confidence.  We try to do as much of the hard work for you as we can, but it is still important for you to check the labels on products for yourself, especially if you are particularly sensitive or have any allergies.

For a quick overview of the FODMAP status of some of the most common ingredients head over to the FODMAP foods page, or head over to our blog for some recipe inspiration.


What takeaway / take-out can I eat?

This is perhaps one of the most difficult questions to answer since ingredients lists are difficult to get hold of, and not all establishments will have the precise information available that you will be asking for because there are so many high FODMAP ingredients and only a handful of them are officially allergens.

We recommend calling ahead at a less busy time and asking to speak to the manager or a chef to see if you can work out which of their options are suitable for you, then make a note of these for future ordering.


What ready meals can I eat?

Unfortunately there are not many convenience foods available at the moment, but here at Fodpod we are striving to change that.  Ready meals are easier to manage than takeout because you can consult the list of ingredients, but be warned that between wheat, onion, garlic, soy, and dairy, many ready meals will be off limits.  If you need a quick meal why not check out our recipe pages?


I'm following the diet but I'm still having symptoms!  What gives?

Firstly, remember that the low FODMAP diet does not cure all ills.  It is possible that you have an intolerance other than FODMAPs, even if you find that the low FODMAP diet helps you to some degree.  Consult your doctor or a registered dietician if you need advice.

Secondly, remember that symptoms from eating FODMAPs can take several hours to set in and can stick around for up to 24 hours.  Keeping a food journal can help you spot connections between what you eat and how you feel.

Thirdly, the effects of eating FODMAPs accumulate over a 24 hour period, known as stacking.  This is because it takes time for FODMAPs to pass through your system.  Stacking can apply to multiple FODMAP serves in a single meal, as well as to servings spread across the day.


I really miss my favourite food…  Can I have a cheat day?

That depends.  Your FODMAP trained dietician would definitely say no during the elimination phase.  After that, FODMAP servings are all about portion sizing, and you might find that you're able to tolerate a slice or two of apple, or even mouthful of your favourite garlic-, onion-, and mozzarella-laden stuffed-crust pizza, but just remember that once your symptoms set in they will be there for a while.  In our experience a cheat day is rarely worth it, but you do you.

If you are coeliac it is important to maintain a strict gluten free diet to avoid doing long term damage to your bowel.


Are there digestive supplements that I can take to allow me to eat FODMAPs again?

Yes, there are lots of digestive supplements available, but a word to the wise - don't expect miracles.

Perhaps the best known and most widely available product is the enzyme lactase, which breaks down lactose.  It is the same enzyme that lactose-free dairy manufacturers add to their products to be able to eliminate up to 99% of the lactose present in their products.  They can achieve this degree of success because they use carefully monitored industrial processes.  The supplements you take (such as drops added to milk) will not have such high efficacy rates because of factors like temperature and agitation, so while taking a tablet might help you eat a slice of cheesecake we would still advise you to exercise moderation.

Of course lactose is just one of the FODMAP carbohydrates.  There are many other supplements designed to target fructose and fructan, and even broad spectrum enzymes that are touted to aid with digestion of all foods, but in our experience their effects vary greatly from person to person and can be quite limited for some people, and they can be very expensive.

When taking supplements always read the label and never exceed the recommended dose.  It's a good idea to check with a health professional first to try and find the root cause of your symptoms; taking tablets can often simply mask the underlying problem.


Some of your certified products contain high FODMAP ingredients.  What gives?

It's all about portion sizing.  The smaller the amount of a high FODMAP ingredient that is present, the less it will contribute to the overall FODMAP content of a product or recipe.  Products that have been officially certified have had their FODMAP levels lab tested and have been proven to fall under a specific threshold so you can buy with confidence.  Of course you may still wish to avoid certain ingredients if you are particularly sensitive or if you are allergic to them, so please always read the label on the product packaging to be sure.