29 Sep What is the low FODMAP diet?
The low FODMAP diet is primarily used to reduce gastrointestinal symptoms in those with Irritable Bowel Syndrome (IBS) by identifying someone’s problematic foods and tolerance levels. When used correctly, the success rate can be has high as 86%!
What are FODMAPs?
FODMAP is an acronym for a group of carbohydrates (sugars) that are fermented by our gut bacteria:
- Fermentable Oligosaccharides
- Disaccharides
- Monosaccharides and
- Polyols
They key types of FODMAPs and examples include:
- Fructose: apples, watermelon, fruit juices, honey
- Lactose: milk, yoghurt, ice-cream, some cheeses
- Fructans: wheat, garlic, onion
- Galacto-oligosaccharides (GOS): chickpeas, legumes, lentils
- Polyols: cauliflower, mushrooms, apples, pears
For most of us, eating these foods will be no issue. However, for those with IBS, they can trigger (not cause) gastrointestinal symptoms, such as bloating, gas, pain, constipation or diarrhoea, which is thought to be due to the higher gut sensitivity in those with IBS
How to follow the Low FODMAP diet
If this diet has been deemed appropriate and necessary by your dietitian and/or your GP to help identify your trigger food & tolerance levels, you’re going to work through three key phases:
Phase 1 – Low FODMAP Diet
This involves you following a strict, low FODMAP diet for about 2 – 4 weeks in order to see if symptoms resolve. Due to the restrictive nature of the diet, it is important to get dietetic support to get enough key nutrients in, such as fibre and some micronutrients.
This part of the diet involves a lot of label reading, swapping products in and out, as well as asking a lot of questions quite out for dinner! A key tool would be the Monash FODMAP app, which allows you to search for almost any food and know what type of FODMAP it contains (if any) and how much you’d be able to eat on a low FODMAP diet.
Phase 2 – Reintroduction
If symptoms have resolved, you’re ready to move onto your next phase. This is where you’ll learn about your personal triggers – both the types and amounts. You continue eating a low FODMAP diet throughout this phase, apart from the ‘challenges’ you’ll take part in each day.
In order to do this, you’ll move through and test each FODMAP sub group with a particular food or drink across a maximum of 3-days to determine whether it causes symptoms and if so, how much you’re able to tolerate before symptoms present. For example, when testing lactose you can test using cow’s milk. Each day will increase the amount, starting with ¼ cup, then ½ cup and finally 1 cup, unless symptoms are too strong to continue. You will then have a day of a ‘reset’, before continuing on to the next FODMAP type.
This phase takes about 6 – 8 weeks to work though.
Phase 3 – Personalisation
Once you’ve worked through each FODMAP type, you should hopefully have a clear understanding of the types of foods you can tolerate and how much you’re able to tolerate per meal. This should give you a lot of confidence in your symptom management and is a very exciting phase to reach!
It is important to include as much variety back into your diet from here, remaining mindful of those identified triggers, as the low FODMAP diet is not intended or recommended to be a long term solution.
Key note:
It is very important to get adequate support if you suspect you have IBS, as many of these symptoms can also be observed in other gastrointestinal diseases or disorders, which may require medical intervention instead of dietary management. Seeking out a diagnosis (which involves assessment of symptoms & ruling out other possibilities) from your GP is a key first step, before then touching base with a dietitian for individualised dietary support.
Alex Stone
Dietitian & Nutritionist
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