The low Fructose, Oligo-saccharide, Di-saccharide, Mono-saccharide and Polyols (FODMAP) diet is a therapeutic diet which is often recommended to people who are diagnosed with functional bowel disorders such as IBS. FODMAPs do not cause IBS however there is substantial scientific evidence to show that limiting FODMAP foods can help symptom management for many IBS sufferers. To understand more about these foods and the effect they have on the body go to

Before embarking on this diet, it is important to consider the following:

  • Restricted diets can increase your risk of developing nutritional deficiencies, this diet is best undertaken under the guidance of a qualified health professional.
  • Do you have the right type of gut condition for this diet to be of benefit? If you haven’t already done so then discuss your symptoms with a GP so they can discuss the suitability of the low FOMAP diet or refer you on to someone who can.
  • It is recommended that you do not follow the low FODMAP diet for longer than 8 weeks if your symptoms are not improving.
  • You will find different information on how much FODMAP a particular food might contain. The now widely recognised guidelines for the UK are from the dietetics team at King’s College Hospital.
  • FODMAPs occur naturally in a wide range of foods.

Tips on how to follow the diet

There are four stages

Stage One – Planning

Stage Two – FODMAP restriction (4 – 8 weeks)

Stage Three – Reintroduction and food challenges

Stage Four – Personalisation


  1. Let your family and friends know that you are going to be making some dietary changes.
  2. Start by planning. Take time to prepare. Choose a realistic start date. Familiarise yourself with the low FODMAP foods list, new ingredients online, in supermarkets and in specialist shops. The Simply FODMAP book has a list of low FODMAP ingredients at the back with details of suppliers link
  3. Download a symptom tracker for your smart phone or get a notebook so you can keep a food symptom diary. Enter your symptoms before you start the diet.
  4. Create a meal plan for the first couple of weeks. You can use the one in the Simply FODMAP book which has the meal plans, recipes and a shopping list

FODMAP restriction

At this stage you follow the diet for 4 to 6 weeks in order to allow enough time to see how you respond.

After completing this stage if you see some improvement in your symptoms then you can move on to Stage Three – reintroduction. If your symptoms do not improve there could be a number of reasons for this which you should discuss with your practitioner.

It is not recommended to follow the low FODMAP diet for more than 8 weeks if symptoms do not improve.

Reintroduction and food challenges

This stage will help you to understand which foods you tolerate and which foods you don’t. Again seek the advice of a practitioner to help guide you through this process.

Start by testing foods from a specific FODMAP group for example orange juice which is in the fructose group. Some foods have more than one FODMAP type for example a mango yoghurt would have two types of FODMAPs, fructose and fructose.  It is important to start with the foods which have only one type of FODMAP. This means you will be testing a single parameter. Included in the Simply FODMAP book is a food challenge table to help guide you through this process

Reintroduction notes

  • Leave three days between each new food that you introduce. This will ensure that any symptoms are not due to a delayed reaction.
  • If you experience symptoms whilst completing a challenge you should stop the challenge and allow symptoms to subside before trying the next food.
  • We recommend that you complete no fewer than six food challenges and allow 6 – 8 weeks to complete this stage.
  • Keep a food symptom diary so you can track which foods you have reintroduced and what symptoms may have occurred.


Once you complete the reintroduction and food challenge stage you should have a good idea of what FODMAP types you do and don’t tolerate so you will know what foods you can reintroduce and which you need to avoid.

It is important to have a varied diet to ensure that you are getting plenty of vitamins and minerals. If you avoid complete food groups for example dairy then you need to be sure you are getting adequate calcium in your diet. This is something you can discuss with a practitioner.

Be aware of the “additive effect” of combining FODMAPs. Even if you tolerated a slice of bread, cream cheese and onion in your individual challenges, if you combine all three together the total FODMAP load may be enough to trigger a reaction.

There are a number of good resources to help you to follow a low FODMAP diet. The Food Maestro APP FODMAP APP enables you to scan foods and look them up to see if they are FODMAP friendly. You may also want to download the Simply FODMAP book

Kings College also have information about the low FODMAP diet on their website