FODMAPS 101, What? How? Why?
Low FODMAP Diet, Charlene Grosse FODMAP Dietitian Perth
Since 2005 a diet low in poorly absorbed short chain carbohydrates and sugar alcohols, termed the low FODMAP diet, has been the focus of many research trials for people suffering from Irritable Bowel Syndrome (IBS) and other gut disorders (Reference). So what are FODMAPs?
What are FODMAPs?
The acronym (abbreviation) FODMAP stands for
Oligosaccharides (Fructans and Galacto oligosaccharides (GOS))
Monosaccharides (excess fructose)
Polyols (Mannitol , Sorbitol, Maltitol, Xylitol and Isomalt)
Where are FODMAPs found?
FODMAPs are found in the foods we each. A few examples of food sources for each of the FODMAPs are listed below however the list is not complete. New data is becoming available all the time as foods are retested and new foods tested.
- Excess Fructose: Honey, Apples, Mango, Pear, Watermelon, High Fructose Corn Syrup
- Fructans: Garlic, Leek, Onion (brown, white, Spanish, onion powder), Spring Onion (white part), Shallots, Wheat (in large amounts), Rye (in large amounts), Barley (in large amounts), Inulin
- Lactose: Milk, icecream, custard, dairy desserts, condensed and evaporated milk, yoghurt
- Galacto-Oligosaccharides (GOS): Legume beans (eg. baked beans, kidney beans, bortolotti beans), Lentils, Chickpeas
- Polyols: Apples, Apricots, Avocado, Cherries, Nectarines, Pears, Plums, Prunes, Mushrooms, sorbitol (420), mannitol (421), xylitol (967), maltitol (965) and isomalt (953).
A Low FODMAP diet and IBS
A low FODMAP diet is now used worldwide as a key management for people suffering with IBS. For many years it was believed that FODMAPs caused IBS symptoms only in the large bowel however recent research has shown that FODMAPs can also have an effect in the small bowel. FODMAPs can cause gut symptoms by the fermentation of these sugars by gut bacteria causing wind, bloating, distension and/or constipation to occur. They can also have an osmotic effect pulling water through the bowel resulting in diarrhoea and the urgency to use your bowels.
For people with IBS a restriction of problematic FODMAPs has been shown to improve overall gut symptoms in 3 out of 4 sufferers of IBS regardless of IBS sub type (diarrhoea predominant, constipation predominant and mixed type IBS). The exciting news for IBS sufferers is that a low FODMAP diet is showing to be far more superior in managing IBS symptoms than any other pharmaceutical or dietary strategy. More on the low FODMAP diet can be found on our FODMAP page.
Is a low FODMAP Diet for me?
It can be difficult to work out what the cause of your symptoms are and for this reason we know may patients self limit consumption of perceived culprit foods without proper support leaving the diet restricted and unbalanced.
Ideally the low FODMAP diet should be followed for 6-8 weeks (restrictive phase) followed by symptom evaluation and graded reintroduction of FODMAP challenges to investigate your individual tolerance (liberalisation phase).
The low FODMAP diet is not meant to be a long – term diet. Fermentation in the bowel is healthy and when foods that cause this fermentation are restricted on the low FODMAP diet the gut microbe changes. To date we do not know what the long-term affect on bowel health is for those that stay on the low FODMAP diet long term.
In reality it is only a minority of the initially eliminated foods that need to be excluded in the final diet. Each person is individual and has a different tolerance level to each of the FODMAP carbohydrates.
Where can I get advice?
The low FODMAP diet is a highly specialised area of nutrition counselling that should be implemented by an specialist dietitian. Our expert dietitians will be able to guide you to identify the type and amount of FODMAPs tolerated and ensure your diet works for you in the longer term. If FODMAPs are not your triggers our dietitians specialise in gut health and are able to work with you on other dietary triggers should the low FODMAP diet not be the answer for you.
by Charlene Grosse
Accredited Practising Dietitian