What is the Low FODMAP Diet?

by Lauren Licatesi, MS, RD

A low FODMAP diet is a dietary approach designed to help individuals with certain digestive disorders, particularly irritable bowel syndrome (IBS), manage their symptoms. FODMAPs are a group of short-chain carbohydrates that are fermentable and can be poorly absorbed in the small intestine. The acronym FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. Common examples of foods high in FODMAPs include:

1. Oligosaccharides:

Found in foods like wheat, rye, onions, garlic, and legumes.

2. Disaccharides:

Lactose is the most well-known disaccharide found in dairy products like milk, yogurt, and soft cheeses.

3. Monosaccharides:

Fructose, mainly found in honey, apples, pears, and some high-fructose corn syrup products.

4. Polyols:

Sugar alcohols like sorbitol and mannitol found in some fruits (e.g., apples, pears), certain artificial sweeteners, and some vegetables (e.g., cauliflower, mushrooms).

The reason people follow a low FODMAP diet is to reduce symptoms such as abdominal pain, bloating, gas, and altered bowel habits (diarrhea or constipation), which are common in individuals with IBS. The idea behind the diet is to limit the intake of foods rich in these fermentable carbohydrates, as they can lead to increased gas production and water retention in the gut, contributing to IBS symptoms.

Here’s how the low FODMAP diet typically works:

1. Elimination Phase:

During this phase, individuals avoid or significantly reduce high-FODMAP foods from their diet for a few weeks. This helps identify whether FODMAPs are contributing to their digestive symptoms.

2. Reintroduction Phase:

After the elimination phase, individuals systematically reintroduce specific FODMAP-containing foods one at a time to identify which ones trigger symptoms. This phase helps determine individual tolerance levels.

3. Personalization Phase:

Based on the results of the reintroduction phase, individuals create a personalized, long-term diet plan that avoids high-FODMAP foods that trigger symptoms while still allowing them to enjoy a variety of foods that are well-tolerated.

It’s important to note that the low FODMAP diet is not a one-size-fits-all solution, and it should be undertaken under the guidance of a healthcare professional or registered dietitian who specializes in gastrointestinal issues. Following this diet can be challenging, as it restricts many common foods, and it’s not meant to be a lifelong approach. The goal is to identify and manage trigger foods to improve the quality of life for individuals with IBS or other digestive conditions.