The Low FODMAP Diet

Researchers Susan Shepard, Peter Gibson, Jacqueline Barrett, and Jane Muir at Monash University and Box Hill Hospital in Australia coined the acronym FODMAP. They discovered that a low FODMAP diet provided IBS symptom relief for ~75% of patients with IBS (irritable bowel syndrome). FODMAPs are a groups of carbohydrates, sugars and fibers found in many foods that can cause digestive issues such as bloating, excessive gas, abdominal pain, constipation, and diarrhea after consumption for those with IBS. Why? These carbohydrates are often poorly absorbed and quickly fermented by your gut bacteria which contribute to IBS symptoms. When gut bacteria breakdown FODMAPs the byproduct is gas (hydrogen, carbon dioxide and methane) which contributes to increased intestinal pressure resulting in abdominal pain, bloating, and excessive gas. The high osmotic effect of FODMAP digestion causes fluid shifts which can lead to diarrhea. Many FODMAPS are malabsorbed which also contributes to IBS symptoms.  Symptoms can occur soon after 4 to 48 hours after a meal since we all have different gut transit times.  By consuming a diet low in FODMAPs many IBS sufferers experience significant improvements with abdominal pain, bloating, gas, diarrhea, and constipation.

Examples of FODMAPs include:

FODMAP stands for the following:

F = Fermentable - Quickly broken down by gut bacteria in the large or small intestine producing excessive gas

O = Oligosaccharides - Found in asparagus, legumes, wheat, onions, garlic, cashews, pistachios, chicory root, and inulin.

D = Disaccharides (Lactose) -Also called milk sugar which is found in cow's milk and many dairy products such as yogurt, ice cream, and cottage cheese.

M = Monosaccharides (Fructose) - Found in some fruits, vegetables, and sweeteners such as honey, agave, and high fructose corn syrup.

 A = And

P = Polyols (Sugar Alcohols) - Found in may stone fruits such as, mushrooms, large portions of celery and sweet potatoes,  low carbohydrate protein bars, and sugar free gums and candies.

It is important to remember that the low FODMAP is a three part diet journey.

  1. The first part is the elimination stage which can last 3-6 weeks.
  2. The next part is the re-challenge stage where one adds back FODMAP groups in a slow, methodical process with the goal of determining which FODMAP groups they are intolerant to and hopefully learning safe thresholds of these foods.
  3. The last part is learning how to live on a adapted low FODMAP diet forever to keep IBS symptoms in control.

It is not recommended to remain on the elimination diet forever and in some situations this may not be the best first approach. Many high FODMAP foods are rich in prebiotics which play an important role in gut health. Long term low FODMAP elimination diet can negatively affect our healthy gut bifida bacteria. It is highly recommended to work with a registered dietitian who specializes in the low FODMAP diet. The end goal is to have the most varied diet one can tolerate.