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Introduction to FODMAPS

What are FODMAPs? Why do they matter? How do you use them?

Introduction to FODMAPS

FODMAPs: Understanding Intolerances and Navigating the Elimination Diet


FODMAPs, an acronym for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols, are a group of short-chain carbohydrates found in various foods. Some individuals experience digestive discomfort after consuming these carbohydrates, which is often attributed to an intolerance to one or more types of FODMAPs. The elimination diet and subsequent re-challenge process help identify specific FODMAPs that may be causing symptoms, enabling individuals to create a personalized dietary plan. This article discusses the various types of FODMAPs, foods that contain them, the incidence of intolerance for each type, and the process of the FODMAP elimination diet and re-challenge.

Major Types of FODMAPs:

There are four main types of FODMAPs:

  1. Oligosaccharides: These are complex carbohydrates formed by the combination of multiple sugar units. Oligosaccharides include fructans and galacto-oligosaccharides (GOS). Fructans are found in foods like wheat, onion, and garlic, while GOS are found in legumes, lentils, and certain nuts.

  2. Disaccharides: Composed of two sugar molecules, lactose is the primary disaccharide associated with FODMAP intolerance. It is found in dairy products such as milk, yogurt, and soft cheeses.

  3. Monosaccharides: These are single sugar molecules, and the main monosaccharide in the FODMAP context is fructose. Fructose is found in fruits like apples, pears, and mangoes, as well as in honey and high-fructose corn syrup.

  4. Polyols: These are sugar alcohols, such as sorbitol and mannitol, found in certain fruits and vegetables like avocado, blackberries, and mushrooms. They are also used as artificial sweeteners in sugar-free products.

Foods Containing FODMAPs:

Each type of FODMAP can be found in various foods, some of which include:

  • Fructans: Wheat, rye, barley, onion, garlic, and inulin (a food additive).

  • GOS: Legumes, lentils, chickpeas, beans, and some nuts like pistachios and cashews.

  • Lactose: Milk, yogurt, soft cheeses, ice cream, and other dairy products.

  • Fructose: Apples, pears, mangoes, watermelon, honey, high-fructose corn syrup, and agave syrup.

  • Sorbitol and Mannitol: Avocado, blackberries, cherries, plums, peaches, mushrooms, cauliflower, and sugar-free products.

Incidence of Intolerance for Each Type:

The prevalence of intolerance to each type of FODMAP varies among individuals. Lactose intolerance, for instance, affects around 65% of the global population, while fructose malabsorption is estimated to affect around 30-40%. Intolerance to fructans and GOS is less well-defined but is considered to be relatively common. Polyol intolerance is the least studied and varies depending on the specific polyol consumed.

FODMAP Elimination Diet and Re-challenge:

The FODMAP elimination diet involves temporarily removing all high-FODMAP foods from one's diet for 4-6 weeks, allowing the digestive system to heal and symptoms to subside. It is crucial to work with a registered dietitian or healthcare professional to ensure adequate nutrition during this phase. After the elimination period, the re-challenge phase begins, which involves systematically reintroducing each type of FODMAP to identify any specific intolerances.

The re-challenge phase typically follows these steps:
  1. Select a FODMAP group to reintroduce (e.g., lactose).

  2. Consume a small amount of a food containing the selected FODMAP (e.g., a small glass of milk) and observe for any symptoms.

  3. If no symptoms occur, gradually increase the serving size of the food over the next few days.

  4. If symptoms return, the individual may have identified a FODMAP intolerance and should stop consuming the food.

  5. Repeat the process for each FODMAP group, allowing a few days between each reintroduction to monitor for symptoms accurately.

The Purpose of the Elimination Diet:

It is important to emphasize that most individuals are not intolerant of all FODMAPs but only one or two types. The goal of the elimination diet is not to promote lifelong abstinence from all high-FODMAP foods but to help individuals identify their specific intolerances. Once the problematic FODMAPs are determined, individuals can create a rational plan for dietary minimization or avoidance of those specific foods. This personalized approach allows for better symptom management while still maintaining a varied and nutritious diet.


FODMAPs are a group of short-chain carbohydrates found in various foods, and some individuals may experience digestive discomfort due to an intolerance to one or more types. The FODMAP elimination diet and re-challenge process help identify the specific FODMAPs causing symptoms, enabling the creation of a personalized dietary plan to minimize or avoid these foods. It is crucial to remember that most people are not intolerant of all FODMAPs and that the elimination diet is not intended for lifelong abstinence from all high-FODMAP foods. Working with a registered dietitian or healthcare professional throughout the process can help ensure nutritional adequacy and proper guidance in managing symptoms.


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