What Is FODMaP?

The Low FODMaP diet is a form of elimination diet that focuses specifically on foods that contain specific types of fermentable sugars. “FODMaP” is an acronym built on the names of the 5 classes of sugars that are eliminated (Figure 1). Increasing numbers of studies support its use for reducing symptoms of irritable bowel syndrome (IBS). However, most of these studies were short-term (less than 6 weeks), utilized dietitians with specialized training, and did not conclusively show that following this diet is more effective than other general dietary advice (e.g., decreasing alcohol, changing the amount of fat in the diet, or increasing dietary fiber).^{1, 2} That said, the FODMaP diet plan can serve as a framework for an elimination diet that can be individualized, especially if more general elimination diet approaches prove unhelpful. 

The Low FODMaP diet works in two ways:

1. It is low in sugars that can be difficult to absorb. These sugars can lead to increased fermentation and gas.
2. Reducing overall sugar intake reduces the osmotic pull of fluids into the intestine, which can reduce diarrhea. This may explain why some research indicates that the FODMaP diet improves pain and boating symptoms by up to 75%, predominately in those with IBS associated with diarrhea.^{2, 3} 

Figure 1. The FODMaP diet's five classes of sugar to avoid