5 common myths about FODMAPs and the low FODMAP diet

5 common myths about FODMAPs and the low FODMAP diet

If you have Irritable Bowel Syndrome (IBS) or know people who have IBS, you may have heard of FODMAPs and the low FODMAP diet.

‘FODMAP‘ is an acronym which stands for Fermentable Oligosaccharides, Dissacharides, Monosaccharides And Polyols; names of groups of poorly-absorbed short-chain carbohydrates, including galacto-oligosaccharides (GOS), fructans, lactose, fructose (in excess of glucose) and sugar alcohols, like mannitol & sorbitol.

Since FODMAPs are poorly absorbed in the small bowel, they are then fermented in the large bowel, creating increased gas production and luminal water. People with IBS are more sensitive to this physiological effect and can experience symptoms like abdominal pain, excessive flatulence, bloating, diarrhoea and constipation.

The low FODMAP diet is a therapeutic diet used for symptom management for people with IBS.  Substantial research indicates that following a low FODMAP diet is the most effective way of managing IBS, with up to 75% people finding an improvement in symptoms.

This blog discusses the five common myths about FODMAPs and the low FODMAP diet.

1. All sugars and syrup are high FODMAP

One tablespoon (equivalent to four teaspoons) of white or brown sugar is low FODMAP.

While sugars and syrups are mainly made of short-chain carbohydrates, not all of them are high FODMAP.

For example, white sugar (or table sugar) is sucrose which is a disaccharide consisting of glucose and fructose. Fructose is a FODMAP when it’s in excess of glucose in food as fructose absorption in the gut is aided by glucose. Although white sugar contains fructose, its fructose is not in excess of glucose and thus it is not high in FODMAP.

Some sugars and syrups are high in fructose in excess of glucose, such as honey and molasses, making them high FODMAP.

To make it easier for you, here is a table distinguishing low FODMAP and high FODMAP options of commonly consumed sugars and syrups.

Low FODMAP sugars and syrups	Low FODMAP serving size	High FODMAP sugars and syrups to avoid!
Brown sugar Coconut sugar Golden syrup Icing sugar Invert sugar Maple syrup Rice Malt syrup White sugar	1 tablespoon 1 teaspoon 7g 1 tablespoon 10g 2 tablespoon 1.5 teaspoon 1 tablespoon	Agave syrup Clover honey Honey Molasses

2. Eating too many FODMAPs can cause IBS

Whilst eating too many FODMAPs can trigger unpleasant symptoms if you have IBS, it is not the cause of IBS!

Although recent research has increased understanding as to IBS’s aetiology and pathophysiology, the precise cause of IBS remains unknown. The condition is likely to be multifactorial. It is suggested that symptoms are related to heightened pain sensitivity, visceral (internal organs) hypersensitivity, atypical gut motility, small-intestinal bacterial overgrowth (SIBO), low-grade inflammation, psychosocial issues and altered gut-brain connections… but not eating FODMAPs! So you don’t have to avoid FODMAPs to prevent the development of IBS!

3. The low FODMAP diet is a healthy diet

The low FODMAP diet is only recommended for people suffering from IBS symptoms for symptom management.

For general population, a healthy balance diet consists of a wide variety of nutritious foods from the five food groups as presented in the Australian Guide to Healthy Eating (AGHE).

Follow the Australian Guide to Healthy Eating for a healthy balanced diet.

Although the low FODMAP diet does not completely eliminate any food group, it does restrict the consumption of certain food from all food groups. Long-term adherence to the diet can lead inadequacy of certain nutrients such as iron, calcium, fibre and prebiotics, especially when the diet is not well planned and not guided by a specialised dietitian.

4. The low FODMAP diet is for life

A strict low FODMAP diet is not for life-long adherence as it restricts the consumption of some food and nutrients and maybe your enjoyment of food too!

Instead, your specialised dietitian will take you through the three phases of the low FODMAP diet and help you develop an individualised version for long-term adherence.

Followings are brief description of each phases. Click on each phase to learn more.

Phase 1 – Elimination

It involves completely eliminating high FODMAP foods for 2-6 weeks until IBS symptoms settle.

Phase 2 – Challenge & Reintroduction

During this phase, patients remain on a low FODMAP diet, whilst re-introducing one FODMAP subgroup at a time. This helps to identify what subgroups and quantities of FODMAPS can be tolerated in order to develop an individualised, modified low FODMAP diet for symptom control.

Phase 3 – Maintenance

The aim of this phase is to maintain a reasonable control of IBS symptoms by balancing between the restriction of some high FODMAP foods, the individual’s food desires and nutritional needs. Patients can enjoy some high FODMAP foods depending on their individual tolerances.

 

5. Gluten-free diet also helps relieve IBS symptoms

   
   

Gluten is a protein found in wheat, rye, barley and oats, and their food products.

Some people find that cutting out gluten in the diet helps relieve their IBS symptoms. Why is that?

Before explaining why the symptom relief occurs, let’s go through some basics of a gluten-free diet:

The gluten-free diet is the therapeutic diet for people diagnosed with coeliac disease. In people with coeliac disease, the immune system reacts abnormally to gluten (a protein found in wheat, rye, barley and oats) and causes inflammation and damages to the gut lining. When the small bowel is damaged, nutrients from food aren’t absorbed properly into the body which can cause nutrient deficiency and gastrointestinal symptoms such as abdominal pain and diarrhoea. Fortunately, cutting out gluten from food allows the small bowel lining to heal and symptoms to resolve.

Reasons why gluten-free diet may relieve some IBS symptoms:

Coincidentally, the three grains that contain gluten (wheat, barley, and rye) are also high in FODMAPs!  Therefore, when you are following a gluten-free diet, you are cutting out some of the FODMAPs too. As a result, IBS patients who are sensitive to the particular subgroups of FODMAPs present in these grains may experience symptom relief.

Keep in mind that: Not all gluten-free foods are low FODMAP. Many gluten free products include soy flour, coconut flour and besan (chickpea) flour all of which are high FODMAP.

Hope this blog helps clear some of your questions about FODMAPs and the Low FODMAP diet!

Until next time,

Good Eating!

Written by: Flora Cheung (APD, AN)
Edited by: Atlanta Miall-Shorten (APD, AN, AccSD)