FODMAPs6 are poorly absorbed short-chain carbohydrates which are fermented in the large intestine by gut bacteria.
The term FODMAP stands for:
- Oligosaccharides (e.g. fructans and galacto-oligosaccharides (GOS))
- Disaccharides (e.g. lactose)
- Monosaccharides (e.g. fructose)
- Polyols (e.g. sorbitol, mannitol, xylitol and maltitol)
The LFD is a three-phase dietary process which helps patients to identify dietary triggers and to move forward with a personalised diet which eliminates or reduces IBS symptoms in the long-term. Phase one is a short-term exclusion diet which eliminates FODMAP-containing foods for two to six weeks. It is recommended that this phase should not last for more than six weeks, with the majority of people achieving symptom improvement within four weeks.7
Phase two is a staged re-introductory process, whereby FODMAP-containing foods are gradually introduced back into the diet as “challenge foods”. This helps patients to identify sensitivities to individual FODMAP subgroups. Once FODMAP “challenges” are completed and dietary triggers are identified, the patient enters into phase three. This is where dietary restrictions are loosened and the patient is encouraged to implement a personalised FODMAP diet which increases dietary variety and balance whilst maintaining IBS symptom control.8
As mentioned earlier, some IBS patients do not follow the LFD diet correctly, and thus remain on the strict FODMAP exclusion stage (phase one) beyond the recommended two to six weeks.9,10 This can result in a very limited diet, which lacks variety and consequently puts a patient at risk of nutritional deficiencies.11 Additionally, long-term adherence to a LFD can have an adverse impact on the balance and diversity of the gut microbiome,12 which could have an impact on longer-term health.