*Geek Box: The Low-FODMAP Diet

*Geek Box: The Low FODMAP Diet

The Low FODMAP Diet [LFD] is often referred to as a diet choice, the way an individual may adopt a vegan diet, for example, but it is important to bear in mind that it is a relatively short-term and specifically defined intervention. The first line intervention for an individual with IBS is not the LFD, but a preliminary adjustment to diet with regard to fatty and spicy food, alcohol and caffein, and promoting of basic general healthy eating advice. This is following exclusion of other potential gastrointestinal conditions and food allergies and intolerances. If the first-line intervention does not lead to improvements in symptoms, the LFD would be implemented as a second-line intervention.

The LFD may be divided into three distinct phases. Phase 1 is ‘Restriction’, which requires strict adherence to the LFD for a period of 4-8 weeks, and during which the individual would be guided to maintain nutritional adequacy while replacing FODMAP foods with alternatives. It is often misunderstood that the LFD is a diet for life: this is incorrect. If no symptom improvement occurs during the Restriction phase of the LFD, the diet is discontinued.

However, if the Restriction phase provides symptom relief, then the individual enters into the Phase 2 ‘Reintroduction’ period. This period is particularly important, because FODMAPs appear to exhibit a dose-dependant effect and the onset of symptoms often relates to the global diet. For example, while an individual with IBS may be able to consume some milk in coffee, or have a single apple, if they ate a bowl of ice cream or if they had an apple with 2 slices of toast, this may trigger symptoms.

Therefore, the goal of the Reintroduction phase is the systematic use of food challenges with FODMAP foods, under the guidance of a nutrition professional, to test individual tolerance to different FODMAP foods and establish a personal threshold for tolerance, for example, 1 slice of bread or 200ml milk, within which the individual does not experience increased symptoms. The aim of the Reintroduction phase is to transition to long-term individual management, where the patient is aware of their own personal tolerance levels to specific FODMAP foods.

Thereafter, Phase 3 is ‘Long-term Management’, with the aim of helping the individual patient find a balance between symptom management and minimising dietary restrictions. This results in an individualised modified diet to the patients particular needs, the exact composition of which for FODMAP foods will differ from person to person. For more on implementation of the LFD, see references (1,6).