Updated: Jun 23
The low FODMAP diet is an elimination diet designed to help decrease the digestive symptoms experienced by people with IBS. Unfortunately, it is not a cure for IBS. Research has found that approximately 3 out of 4 people with IBS have their symptoms improved on this protocol. The protocol has three phases, and it is essential to complete each phase. It is important to note that it is NOT a weight loss diet. It is also not the only option for IBS symptom management. This article summarizes the key points of the low FODMAP diet.
NOTE: You should not attempt this diet on your own, as it was made to be completed with the help of a Registered Dietitian. Always talk to your doctor and/or dietitian before making dietary changes.
WHAT ARE FODMAPS?
FODMAPs (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, And Polyols) are a group of carbohydrates found in food that are highly fermentable. The fermentation of FODMAPs by bacteria in the bowel (also known as the production of gas) is a normal and healthy part of digestion. For people with IBS however, eating foods high in FODMAPs may trigger symptoms such as excess gas, bloating, distension, cramping, constipation and/or diarrhea.
Some foods contain no FODMAPs, some foods contain only one type of FODMAP, and some foods contain multiple types of FODMAPs. Reducing the amount of high FODMAP foods in your diet may help improve IBS symptoms. Every person is unique, and every person with IBS has a different reaction to each type of FODMAP.
There are 5 types of FODMAPs:
Lactose – found primarily in dairy products (e.g., milk, yogurt, etc.)
Fructose – found primarily in certain fruits, vegetables, and sweeteners (e.g., mango, asparagus, honey, agave, etc.)
Fructans – found primarily in certain fruits, vegetables and grains (e.g., garlic, onion, wheat, etc.)
Galacto-Oligosaccharides (GOS) – found primarily in certain legumes and nuts (e.g., kidney beans, pistachios, cashews, etc.)
Polyols – found primarily in certain fruits and vegetables, and used as a sweetener in certain processed foods (e.g., peaches, cauliflower, sugar-free gum)
For the most part, you cannot easily guess which foods contain FODMAPs. FODMAP content of foods is determined in food testing labs. Monash University releases the results of their tests through their App. A chart summarizing the FODMAP content of foods using the App is located lower down on this page.
Gluten is not a FODMAP. Wheat, barley and rye are limited on the low FODMAP diet due to their fructan content. It is only necessary to avoid trace amounts of gluten for individuals who have Celiac disease or gluten sensitivity.
WHAT IS AN ELIMINATION DIET?
An elimination diet is where you remove all foods from your diet which may be causing symptoms for some time, and then try challenging the FODMAP groups (i.e., eating high FODMAP foods) one at a time. This is how we find out which high FODMAP foods you react to and how much you can tolerate. The low FODMAP elimination diet has three phases.
Phase 1 – Elimination: Only eat foods that contain little or no FODMAPS for approximately 2 – 6 weeks (or until symptoms are well managed).
Phase 2 – Reintroduction/Re-challenge: After 2 – 6 weeks, and improvement in symptoms, FODMAP groups are systematically tested one by one and symptoms are recorded. This phase will take approximately 8 weeks. A personalized schedule for reintroduction should be made with your dietitian.
Phase 3 – Maintenance/Modifed Diet: After challenging each FODMAP group, a list of “safe” foods (i.e., foods you can eat without symptoms) and a list of “trigger” foods (i.e., foods which give you symptoms at certain serving sizes) are created. A variety of “safe” foods are now consumed. There may be some “trigger” foods you are fine with in small quantities.
The Reintroduction phase is the most important phase of the diet. It is likely that not all 5 FODMAPs will cause you significant symptoms. The only way to find out how much of each FODMAP you can eat without experiencing symptoms is to systematically test them. Most individuals can reintroduce some FODMAPs back into their diet while maintaining symptom control.
The low FODMAP diet will require a lot of effort, but it can have a significant positive impact on your symptoms. You may see improvement in your symptoms in the first week of the diet, or it may take a few weeks to see an improvement. It is important to start the diet at a time when you have the time to commit to a large dietary change. For example, the day before a big vacation is not a good time.
It may be a lot of work, but it is important to still eat a variety of foods while on the low FODMAP diet. Eating a variety of foods helps us get enough of the all the nutrients we need! Two nutrients of concern are calcium and fibre. Try to eat a variety of calcium containing foods (e.g., hard cheeses, lactose-free milk, lactose-free yogurt, fortified milk alternatives, firm tofu, etc.). You should aim to meet the fibre requirements each day (25 g for women, 38 g for men), especially if constipation is one of your symptoms. Fruit, vegetables, whole grains, nuts and seeds are great sources of fibre. Keep hydrated by sipping on water throughout the day and when eating high fibre foods.
There may be some low FODMAP foods which still trigger symptoms for you. If you know of any other foods which cause symptoms (e.g., caffeine, alcohol, greasy foods, etc.), you should continue to avoid those foods during the diet and inform your dietitian.
You made it to the bottom of the page! I hope you took the time to read the above information thoroughly. Before starting the low FODMAP diet, always talk to your doctor and/or dietitian.
There are other options for IBS symptom management. You may want to try these simple dietary changes for IBS management before the low FODMAP diet.
I want to emphasize one more time that this is a medical diet and meant to be done with the help of a FODMAP educated dietitian. A dietitian will help you to implement the diet, eat a variety of nutritious and tasty foods, avoid accidentally eating high FODMAP foods, troubleshoot problems and achieve good symptom control.
I offer nutrition counselling and coaching across Netherlands for IBS and other digestive disorders. In one-on-one sessions with clients, I give individualized advice and help make the low FODMAP diet as easy to follow as possible.
Please feel free to contact me for more information, I am always happy to talk about food!
DOWNLOAD HIER THE FODMAP CHART.