What is the Low FODMAP Diet?
Written by: Katie Ryan (Accredited Practising Dietitian)
What does the acronym FODMAP mean?
The term FODMAP means – Fermentable, Oligosaccharides, Disaccharides, Monosaccharides, And, Polyols.
FODMAP’s are a group of short chain carbohydrates and sugar alcohols that are poorly absorbed in the intestines and are fermented by gut bacteria. This causes the pain, bloating, and motility issues we experience with IBS.
What are the different groups of FODMAP’s?
There are six different groups of FODMAP’s. Let’s breakdown the different FODMAP groups…
FRUCTANS
Fructans are a type of prebiotic, meaning they selectively stimulate the growth of beneficial gut bacteria. Fructans are malabsorbed in the small intestine by all people to varying extents. This means they reach the large intestine where they rapidly ferment by resident bacteria (prebiotic role). Typical symptoms from Fructan malabsorption include reflux, flatulence, bloating, and abdominal pain.
Examples of HIGH Fructan foods include: Onion, Garlic, Wheat, Rye, Barley, Dried Fruits,
GALACTO-OLIGOSACCHARIDES (GOS)
Galacto-oligosaccharides (GOS) are a type of oligosaccharide that similarly like Fructans are a prebiotic. People who malabsorb GOS lack the enzyme (a-galactosidase), which is needed to breakdown GOS into its simple sugar units. Similarly to Fructans, malabsorbed GOS reaches the large intestine where it’s rapidly fermented by gut bacteria (prebiotic role).
Examples of HIGH GOS foods include: Black Beans, Red Kidney Beans, Baked Beans, Green Peas, Beetroot, Soy Milk (from Soy beans), Cashews, and Pistachios.
FRUCTOSE
Fructose is a monosaccharide (single sugar unit) that is found naturally in many fruits. A high intake of fructose often causes symptoms such as abdominal pain, diarrhea, and gas.
Examples of HIGH Fructose foods include: Apple, Pear, Mango, Asparagus, Sugar snap peas, Honey, and Fruit Juices.
LACTOSE
Lactose is a disaccharide (two sugar units). Lactose is broken down by the enzyme lactase. People who malabsorb lactose lack the enzyme lactase. This causes water to attract into the small intestine and moves into the large intestine where it is fermented by gut bacteria. Common symptoms include bloating, wind, stomach cramps, and diarrhoea. There are many reasons why someone may lack the enzyme lactase including – ethnicity, genes, gastroenteritis, and undiagnosed coeliac disease.
Examples of HIGH Lactose foods include: Cows Milk, Some Yoghurts, Custard, and other Dairy based foods.
POLYOLS
Polyols are sugar alcohols that include Sorbitol, Mannitol, Xylitol, and Maltitol. Malabsorbed polyols enter the large intestine and are fermented by colonic bacteria, causing gas production and bloating.
SORBITOL
Examples of HIGH Sorbitol foods include: Apples, Avocado, Nectarines, Plums, Watermelon, Lychees, and Apricots.
MANNITOL
Examples of HIGH Mannitol foods include: Mushrooms, Cauliflower, Snow Peas, and Celery.
It is important to understand that although you may get GI symptoms with High FODMAP foods, majority of people with IBS do not experience these symptoms with all six groups of FODMAP’s. In fact, every individual has their own threshold to each different group of FODMAP and this threshold can change through different periods of your life.
So, what is the Low FODMAP Diet?
The Low FODMAP Diet is one dietary method used to manage the functional bowel disorder, Irritable Bowel Syndrome (IBS). Approximately 70% of people with IBS who have followed a Low FODMAP Diet found improvements in their overall functional symptoms, the severity of their symptoms, and their quality of life. The Low FODMAP Diet is a 3–6-month process that involves 3 phases –
Phase 1: Low FODMAP Diet
Phase 1 involves following a relatively strict Low FODMAP Diet for 2 – 6 weeks under the guidance of a dietitian. This means all HIGH and MODERATE FODMAP Foods from all 6 groups are either not consumed or consumed in LOW amounts for the 2 – 6 week period.
Phase 2: FODMAP Reintroduction
Phase 2 involves introducing challenges one by one to the different FODMAP groups to determine your symptom triggers. This is achieved by introducing each group of FODMAP (Fructans, GOS, Lactose, Fructose, Sorbitol, Mannitol) one at a time, while remaining on a Low FODMAP Diet. Phase 2 can take anywhere between 6-12 weeks to complete.
Phase 3: Personalised FODMAP Diet
Once all the FODMAP challenges are complete, your Dietitian will help determine the foods and FODMAP groups that cause your IBS symptoms. You will then work closely with your Dietitian to identify your tolerance to FODMAP groups and create an ongoing personalised diet and plan. You will then be able to reintroduce FODMAP foods back into your diet and be clear on the foods that cause your symptom triggers and your tolerance to them.
Should you be following a Low FODMAP Diet?
It is important to only commence a Low FODMAP Diet under the guidance of a specialised Dietitian. The Diet (or I like to call it a PROCESS), is relatively restrictive. Working closely with a Dietitian while going through the Low FODMAP process will ensure you are not cutting out any unnecessary foods and still receiving adequate nutrition. At Simplistic Nutrition, I step my clients through a simple step by step process to find symptom relief and get you back to living a pain free, normal life sooner rather than later. If you think the Low FODMAP diet will benefit you, click here to make an appointment with Simplistic Nutrition (clinic and online consultations available).
References
Monash University (2019). FODMAPs and Irritable Bowel Syndrome. Monash University https://www.monashfodmap.com/about-fodmap-and-ibs/
Peters SL, Yao CK, Philpott H, Yelland GW, Muir JG, Gibson PR. Randomised clinical trial: the efficacy of gut-directed hypnotherapy is similar to that of the low FODMAP diet for the treatment of irritable bowel syndrome. Aliment Pharmacol Ther. 2016 Sep;44(5):447-59. doi: 10.1111/apt.13706. Epub 2016 Jul 11. PMID: 27397586.