Low fodmap diet can improve ibs symptoms in 3 out of 4 people

Low FODMAP diet has been clinically tested and proven to help 70-80% people with IBS to reduce or eliminate symptoms. IBS or Irritable Bowel Syndrome is a gastrointestinal disorder that affects 35 million Americans and has an adverse effect on the quality of life.  The symptoms include bloating, abdominal pain, diarrhea and/or constipation and affect daily activities, work performance and personal life of many people. The cause of IBS is still a mystery, however there are many theories suggesting that it can possibly be due to motility issues, dysbiosis, visceral hypersensitivity, or psychological influence involving the gut-brain axis.  Even though this condition is not curable, it can be controlled with diet and lifestyle modifications.

Monash University in Australia has developed a low FODMAP diet that limits or eliminates specific carbohydrates that are not digested and poorly absorbed in the gut.

FODMAP acronym stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols.


Fructans and galacto-oligosaccharides (GOS) found in legumes and pulses, onions and garlic or wheat and rye.


Lactose found in dairy products, such as milk, yogurt and cheese.


Fructose found in fruits, such as apples, HFCS, honey and others.


Sorbitol and mannitol, or sugar alcohols, found in some fruits and vegetables, as well as artificial sweeteners and foods made with them.

Simply said, FODMAPs are carbohydrates that are poorly absorbed in the gut and travel to the large intestine undigested to be fermented by gut bacteria. The by-product of the fermentation is gas, which accumulates in the gut causing bloating, belly distention and abdominal pain. Low FODMAP diet is not a lifelong diet; it is only designed to be for about 10-12 weeks, because it restricts many healthful foods and this can lead to many nutrient deficiencies.

Low FODMAP diet has 3 Phases:

Phase I: Elimination

Phase I eliminates all high FODMAP foods for 2-6 weeks to let the gut heal. Usually people start feeling better during this phase. However, progressing to the next step is very important, because this is the whole point of this diet.

Phase II: Re-Introduction

During this phase high FODMAP foods are re-introduced to test if they trigger the symptoms. Starting with small amount and gradually increasing it can help to identify the tolerance level. Some people can eat small amounts of beans with no problem, however larger amounts can lead to excessive gas, bloating, abdominal pain and diarrhea.

Phase III: Personalization

This is the last step in low FODMAP diet, where all foods are brought back except those that have caused a distress in Phase II. It is needed to eliminate nutritional deficiencies and decrease dietary restrictions to avoid poor quality of life. Also, there is no need to restrict prebiotics that are tolerated well because they are very beneficial for microbiome diversity.

Researchers at Monash University are constantly testing different foods for FODMAPS to create a database. Some foods are free from FODMAPs, such as meats, oils, carrots, arugula, grapes and etc, whereas others have moderate and high amounts of FODMAPs, such as 25 and 35 green beans respectively.  Scientists has developed cut-off values for oligosaccharides, polyols, excess fructose and lactose found in standard serve, above which people experience adverse symptoms.  Using High and Ultra-High Performance Liquid Chromatography foods are being tested and analyzed for the presence of FODMAPs.

In Summary, low FODMAP diet is designed for people with IBS, and 3 out of 4 people with IBS will see improvements if they follow it correctly. FODMAPs are a group of carbohydrates that go through GI tract undigested and poorly absorbed attracting water to the colon and causing diarrhea. When FODMAPs reach the large intestine, bacteria use them as a food source with producing gas as a result of fermentation.

Low FODMAP diet is restrictive and confusing, thus working with a health practitioner, such as the dietitian, will increase the chance for success in managing your IBS symptoms. Sign up for my free 20 minutes IBS-Control call to see if we are a good match working together in finding solutions to eliminate your symptoms. I am a Registered Dietitian Nutritionist in Chicago, IL who had completed the training at Monash University.

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