If you have irritable bowel syndrome (IBS), you may have heard that FODMAPs could be contributing to your symptoms. But what exactly are FODMAPs, which foods contain them, and does that mean you have to give up your favorite foods?
The good news is that understanding FODMAPs can help you make more informed food choices. And following a low FODMAP diet does not mean eliminating entire food groups forever.
The short answer
What are FODMAPs?
FODMAPs are certain types of carbohydrates found naturally in many foods. Some are poorly absorbed in the small intestine and can contribute to gas, bloating, abdominal pain, diarrhea, and other symptoms in people with irritable bowel syndrome (IBS) .
FODMAPs are not inherently unhealthy. The goal is to identify which ones cause symptoms for you, and in what amounts.
What does FODMAP stand for?
FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides And Polyols. These terms describe several groups of short-chain carbohydrates.
The word fermentable refers to the way bacteria break down these carbohydrates in the gut, producing gas in the process.
Why can FODMAPs trigger IBS symptoms?
When some FODMAPs move through the digestive tract, they can draw water into the intestine. Others are fermented by gut bacteria, producing gas.
These are normal digestive processes, but people with IBS often have heightened sensitivity to what is happening inside their intestines.
That can result in bloating, visible distension, abdominal pain, excessive gas, diarrhea, constipation, or a combination of symptoms.
IBS is a disorder of gut-brain interaction. Although it is not generally life-threatening, symptoms can be severe and significantly affect daily life.
Important to understand
Not everyone reacts to the same FODMAPs
One person may struggle with fructose, while another reacts primarily to fructans or polyols. Many people tolerate certain FODMAPs in smaller portions. Personal tolerance matters more than a universal list of forbidden foods.
The four main FODMAP groups
You do not have to memorize the scientific terminology. The important thing is understanding where these carbohydrates appear in everyday foods.
Oligosaccharides
This group includes fructans and galacto-oligosaccharides (GOS).
Common sources include garlic, onions, wheat, rye, beans, lentils, and cashews.
Disaccharides
The relevant FODMAP in this group is lactose, the sugar found in milk and some dairy products.
Common sources include regular milk, ice cream, and certain soft dairy products.
Monosaccharides
This group refers to excess fructose, when fructose is present in greater amounts than glucose.
Examples include apples, mangoes, honey, and certain foods containing added fructose.
Polyols
Polyols are sugar alcohols, including sorbitol and mannitol.
They occur naturally in certain fruits and vegetables, and some are added to sugar-free products, including gum and candy.
A key FODMAP principle
Serving size changes everything
A food that is high FODMAP in one serving may be low FODMAP in a smaller serving. For example, foods such as almonds can have low FODMAP portions even though larger amounts contain more FODMAPs.
That is why a simple list of foods to avoid is not enough to follow the diet accurately.
For a deeper explanation, read: What Is A Low FODMAP Serving Size?
Can a food contain more than one FODMAP?
Absolutely. Some foods contain multiple FODMAP groups, which can make their effects on digestion more complex.
For example, apples can contain excess fructose and sorbitol, while some legumes contain multiple oligosaccharides.
The FODMAP content of foods may also vary by variety, ripeness, processing, preparation, and serving size. Laboratory testing is essential for accurately determining FODMAP content.
For current serving information, consult the Monash University FODMAP resources and FODMAP Friendly . Both provide food-testing information and smartphone apps.
What foods are naturally low in FODMAPs?
There are many foods with very low or negligible FODMAP content, along with foods that have generous low FODMAP serving sizes.
Examples include:
- Eggs, unseasoned meat, poultry, and fish
- Rice and quinoa
- Carrots and cucumbers
- Many varieties of lettuce
- Oranges and strawberries in appropriate portions
- Pure cooking oils
- Chives and green scallion tops
These are examples, not a complete food list. The amount you eat and the way foods are prepared can still matter.
How does the low FODMAP diet work?
The low FODMAP diet was developed through research at Monash University in Australia. It is one of the dietary approaches used to help manage IBS symptoms.
It is important to understand that this is not intended to be a lifelong elimination diet. There are three distinct phases.
Elimination
For a limited period, high FODMAP foods are reduced to see whether IBS symptoms improve. This phase is generally short-term and ideally undertaken with guidance from a FODMAP-trained dietitian.
Challenge
Different FODMAP groups are systematically reintroduced to help determine which ones trigger symptoms and the amounts you can comfortably tolerate.
Integration
Your diet is personalized to include as much food variety as possible while managing symptoms. The goal is long-term flexibility, not unnecessary restriction.
Read our complete guide to the low FODMAP diet for more information about these phases.
Before you begin
Work with a qualified dietitian
A low FODMAP diet can be helpful, but it is also restrictive when followed incorrectly. IBS-like symptoms can have other causes, so getting an appropriate diagnosis matters.
A FODMAP-trained registered dietitian can help you maintain adequate nutrition and identify your individual food tolerances.
Does low FODMAP mean gluten-free or dairy-free?
No. This is one of the most common misunderstandings about the diet.
Wheat contains fructans, which are FODMAPs, but gluten is a protein rather than a FODMAP. Many people can include appropriate servings of wheat-containing foods in their personalized diet.
Similarly, the low FODMAP diet is not dairy-free. Some dairy foods contain relatively little lactose, and lactose-free alternatives can be helpful.
Anyone with celiac disease must still avoid gluten, regardless of FODMAP content.
How do you know which foods are low FODMAP?
Because FODMAP content cannot reliably be determined from an ingredient list alone, we strongly recommend using the laboratory-tested information provided through Monash University and FODMAP Friendly.
Their apps help you understand serving sizes and identify foods that may fit your individual needs.
Helpful tools for getting started
Free low FODMAP resources you can download
We have created practical tools to make learning about FODMAPs easier, including printable food lists, guides, and resources that you can keep on hand while shopping, cooking, or eating out.
These tools are designed to complement, not replace, up-to-date laboratory-tested serving information.
Explore our free downloadable resources
The bottom line
FODMAPs are found in many nutritious, everyday foods. They are not inherently bad, and having IBS does not mean you must avoid all of them.
The purpose of the low FODMAP diet is to discover your personal triggers, manage symptoms, and return to the broadest, most enjoyable diet you can comfortably tolerate.
With reliable food-testing information, appropriate professional guidance, and the right resources, learning about FODMAPs can become much less overwhelming.