What are FODMAPs? We’ve got all you need to know

What does FODMAP stand for?

The term FODMAP stands for Fermentable, Oligo -, Di- and Mono-saccharides and Polyols and if you have IBS, then you more than likely have heard about FODMAPs. The term FODMAPs was first coined by investigators in Monash University, in Melbourne, Australia back in 2005. While the term was a new one, investigators and clinicians had known for several decades before this that certain carbohydrate sugars were problematic for people with various digestive conditions, particularly IBS.

So what are FODMAPs? These are naturally-occurring sugars and chains of sugars (which are carbohydrates) found in different foods, particularly plant-based foods and dairy produce. They aren’t bad for you and you shouldn’t stop eating plant-based foods or dairy, so please keep reading!

Why are FODMAPs problematic?

These FODMAP-containing carbohydrates tend to be poorly absorbed in the small intestine and are then digested (or fermented) by the gut bacteria in the large intestine. This is where the word fermentable comes from in FODMAP. In the small intestine undigested FODMAPs draw in water and can lead to bloating and diarrhoea. When they reach the large intestine they are fermented by the normal gut bacteria and this produces gas which can lead to further bloating, flatulence, cramps and diarrhoea, or less commonly constipation. Foods with a high FODMAP content tend only to trigger troubling gut symptoms in people with IBS, due to increased gut sensitivity in those affected (learn more on the IBS and Gut-Brain Axis sections of our website).

Reducing the FODMAP content in your diet can help reduce symptoms such as bloating, diarrhoea and excessive gas but does not tend to reduce constipation. If anything, reducing FODMAPs, because many of these foods are fibre-containing, can worsen constipation. 

Fermentable or Fermented? 

As an aside, there are so many terms to get to grips with nowadays, we just want to make sure that you don’t get the terms ‘fermentable’ mixed up with ‘fermented’. Fermentable foods are ones like FODMAPs, which lead to fermentation by your own gut bacteria. Fermented foods on the other hand are ones that have already been fermented by healthy bacteria before you eat them. Fermented foods include kefir, kombucha, natto, sauerkraut, cheeses to name but a few. We’ll be talking about fermented foods more down the line, as everyone is so interested in them, including us.

The Low FODMAP Diet

Because foods that have a higher FODMAP content can trigger IBS symptoms, it made sense to trial a diet that contained foods with a lower FODMAP content- the low FODMAP diet.

How effective is a Low FODMAP diet for IBS?

A number of studies have shown that a diet low in FODMAPs can be helpful in reducing symptoms in up to 75% of people with IBS. However not everyone will respond, or respond well-enough. This is particularly the case if you have marked constipation-predominant symptoms or if you have high levels of stress or anxiety. This is one of the reasons, we strongly believe in a holistic approach, where you look at all the triggers – diet (including FODMAPs), your mental health and other lifestyle factors.

Sample foods that contain FODMAPs
Sample Foods that contain FODMAPs - The Gut Experts

Which foods contain FODMAPs?

  • Remember the F in FODMAPs, refers to Fermentable – we described this above. 
  • Oligo-saccharides – there are two main types, Fructans and Galacto-oligosaccharides (GOS). 
  • Fructans are chains of the fructose sugar with a glucose sugar at the end. These are mainly found in wheat products for example bread/breakfast cereal/pasta, and some vegetables such as onion, garlic, and artichoke. 
  • Galacto-oligosaccharides (GOS) are chains of the galactose sugar joined with fructose and glucose at the end. These are mainly found in beans, pulses, cashew and pistachio nuts.
  • Di-saccharides: ‘Di’ means double and the most common double sugar that can be poorly digested is lactose, which is found in all dairy products; milks, yoghurt, soft cheese.
  • Monosaccharides; ‘Mono’ means ‘one or single’ and examples of single sugars are glucose and fructose. Glucose is very well and rapidly absorbed, whereas fructose, the fruit sugar, if consumed in large amounts can be poorly absorbed, particularly in those with IBS. Fructose is found in honey, lots of fruits in varying amounts, and fruit juices.
  • Polyols – these are sugar alcohols and include sorbitol, mannitol and xylitol. They’re found in some fruits and vegetables, for example apricots, avocados, cauliflower and mushrooms.  They are also used as artificial sweeteners in some foods and drinks e.g. sugar free chewing gum and sweets. 

That’s a lot to take in.

Elaine’s experience of the low FODMAP diet

Elaine travelled to Australia in 2010 to meet with one of the main researchers of the low FODMAP diet. She was very interested in their approach as she was already getting very good results with many of her IBS patients by adjusting the amounts of fructose, onion and garlic in their diets. People had recognised for several decades that these foods were often triggers of troublesome gut symptoms in IBS patients. Before the FODMAP diet was even born she, and others were already practicing a modified version of it in their clinics. 

Elaine embraced the low FODMAP diet as part of her dietary solutions for IBS, and has also educated many colleagues in its benefits for IBS patients. Through years of experience, her philosophy has further evolved, as she has found in her practice that many patients with IBS can include more wheat and dairy in their diet. As such she doesn’t advocate a strict gluten- or lactose-free version of the low FODMAP diet.

Should I avoid foods high in fermentable food components if I have IBS?

FODMAPs aren’t unhealthy or “bad” for you. In fact, many foods high in FODMAPs are highly nutritious, and delicious and can be good foods for our gut bacteria – avocado, mango or hummus anyone? Whilst FODMAPs are mostly healthy foods for the gut, diets high in FODMAPs can be problematic for people with IBS for all the reasons we mentioned above. Thus some people with gut problems may benefit from a low FODMAP diet plan and it’s reasonable to trial a period of removing them from your diet.

The low FODMAP diet can however be highly restrictive and it’s important that you only follow it under the supervision of a gut specialist Registered Dietitian to ensure you’re still getting all your important nutrients and to feel supported. It’s also essential to do the reintroduction phase after the restriction phase so as to identify which foods may be problematic for you. Please note, you should only embark on this diet if you have been medically diagnosed with IBS. 

However, 1 in 4 people with IBS won’t find relief from their IBS symptoms following this diet and it can also cause some negative knock-on effects on the Gut Microbiota (GM). We don’t want that. 

We really believe in an individualised approach to management of gut symptoms and therefore would again stress the importance of working with a gut specialist Registered Dietitian to discover your level of tolerance for different types of foods. 

I’m a vegan, can I remove FODMAPs from my diet?

Following a diet low in fermentable foods is often more challenging if you’re a vegan because many staples of a vegan diet are high in FODMAPs such as beans and pulses. We’re seeing more and more patients come to us that have adopted a vegan diet in a bid to quell their IBS symptoms and their efforts are making things worse. It’s often quite a surprise when we reveal that their new healthy lifestyle is in fact making things worse. There are, of course, lots of plant-based foods that are low in fermentable food components but enjoying these and meeting your protein, vitamin and mineral needs can be very tricky. Again, it’s important to work with a gut specialist Registered Dietitian to develop a plan that’ll work for you. 

Check out the vegetarian and vegan-friendly recipes in The Gut Experts Kitchen for some gut friendly meal ideas.

So, what should I do?

If you’ve been diagnosed with IBS and are suffering with your symptoms and yet to examine your diet, consider making an appointment with a gut specialist Registered Dietitian.

It’s also important to remember that dietary solutions aren’t a “magic fix” for everyone. Managing stress, anxiety and taking regular exercise all play a part in managing IBS symptoms and of course some people will also need medication. 

Visit the Self Care section on our website for more on looking after your overall wellbeing.

 ©The Gut Experts 2021


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