Nutrition Meets Food Science

Low FODMAP Diet – The Key to IBS Management

Some ‘diets’ come and go like quirky fashion trends, while others with more scientific backing last longer like the classic, well-thought fashion statements. The Low FODMAP diet is one such well researched, therapeutic diet for the management of irritable bowel syndrome (IBS).

FODMAP is short for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. In simple words: fermentable sugars.

Some examples of FODMAP containing foods are:

Wheat breads by Welcome to all and thank you for your visit!ツ from Pixabay

Oligosaccharides e.g. Fructans & galacto oligo-sachharides (GOS) – Onion, Garlic, Dates, Dried fig, Spring onion, Wheat and wheat products, Green peas, Cashew, Pistachio, Soy, Red kidney beans, Black beans, etc.

Onion & Garlic by Shutterbug75 from Pixabay

Disaccharides e.g. lactose – Milk, curd, cream, custard, etc.

Milk by Дарья Яковлева from Pixabay

Monosaccharides e.g. fructose – fruit juices, mango, peach, honey, etc.

Honey by Дарья Яковлева from Pixabay

Polyols e.g. mannitol & sorbitol – Apple, Pear, Coconut milk, Watermelon, Apricot, Artificial sweeteners, Mushrooms, Cauliflower, Sweet potato, etc.

Apple strudel by RitaE from Pixabay

Mushrooms by congerdesign from Pixabay

We humans, cannot digest some naturally present sugars (FODMAPs) in food because of a lack of enzymes that are needed to break them down. Instead, these sugars are fermented in the large intestine and produce some gases and food for the helpful bacteria living in our gut. This gas usually causes little or no discomfort in healthy individuals. But those living with IBS experience varying disabling symptoms like abdominal pain, bloating, diarrhea, constipation, etc, every time they consume FODMAP-containing foods. These symptoms may hinder daily activities like going to work, dining out, exercise, etc. This negatively affects the quality of life of an individual living with IBS.

Abdominal pain by Darko Djurin from Pixabay

On the other hand, some individuals may not be able to absorb the broken-down sugars effectively. For example, individuals that experience IBS symptoms after consuming dairy, may not be lactose intolerant because of lack of the digestive enzyme (lactase), but because of impaired absorption. This also increases the gas and fluids in the large intestine.

Having said that, the bloating you have after having too many pani puris, or an extra serving of tea or coffee is not a result of irritable bowel syndrome. IBS is much more serious and heavily affects the quality of life of the patient. It should always be diagnosed by a trained gastroenterologist and never be self-diagnosed.

Pani Puri by Nisha Gill from Pixabay

What are the benefits of a low FODMAP diet?

Food is a major trigger for digestive disorders. So, the simple logic behind the low FODMAP diet is the restriction or complete elimination of foods that cause trouble. This simple dietary change can manage IBS symptoms and improve the quality of life of the patient.

Should the same diet plan be followed by every IBS patient?

Just like each one of us has different favourite comfort food and a different dish we strongly dislike, every IBS patient’s gut will produce symptoms only when specific FODMAPs are consumed. It is necessary to make sure that only the trouble-causing foods are eliminated and the excess restriction is not imposed on food because it may lead to otherwise avoidable nutrient deficiencies.

Who should follow a low FODMAP diet?

A low FODMAP diet should be followed only under the professional guidance of a dietitian/nutritionist by individuals diagnosed with irritable bowel syndrome. Some research also claims the efficacy of the low FODMAP diet in the management of cystic fibrosis, some autoimmune disorders, etc. Though further research is required to draw conclusive results.

Image by Aline Ponce from Pixabay

Can vegetarians follow a low FODMAP diet?

Yes, vegetarians can follow a low FODMAP diet, but one cannot deny that vegetarians need to be more vigilant about their protein intake because of restrictions on dairy, pulses, and legume intake.

Is the low FODMAP diet a weight loss diet?

No, a low FODMAP diet is a short term, restrictive, therapeutic diet for the management of IBS. Unnecessary restriction of FODMAP food from the diet may cause a deficiency of vital vitamins, minerals, and protein.

Vitamins & Minerals Foods by Devon Breen from Pixabay

How long should one follow the low FODMAP diet?

The low FODMAP diet is a short-term diet and comprises of three phases that may last up to 12-14 months.

The 3 phases of a low FODMAP diet prescription are:

  1. Restriction phase – This is the first phase of the low FODMAP diet that lasts for 3-6 months. During this period all FODMAP containing foods are excluded from the diet to evaluate if the FODMAPs are really the trouble-causing foods. If the symptoms are managed with a zero FODMAP diet, the next phase is started. If not, other kinds of therapies like psychotherapy, surgical vagal resection, etc. are looked at.
  2. Reintroduction or challenge phase – Not every IBS patient experiences symptoms after consuming all FODMAP containing foods. During this phase, some food from each FODMAP group is reintroduced in the diet one by one (over a period of 3 days), with increasing portion size to identify which FODMAP and in what quantity is well tolerated and which is causing symptoms. E.g.- to check for the tolerance of mannitol, mushroom can be introduced in small amounts, slowly increasing the portion size to a regularly consumed quantity and gastrointestinal symptoms must be observed and noted for each serving size. The results will then be used to find if mannitol is tolerated and if tolerated, in what amounts.
    Nutritionist by Sebastián García from Pixabay
  3. Personalization phase – When the trouble-making FODMAP group and quantity is identified, the dietitian helps the patient build a sustainable nutrition plan that excludes that FODMAP, making sure that the diet is well balanced without risk of any nutrient deficiencies.

Does this mean that once a personalized diet is prescribed you are all set forever? No, gut behaviour tends to change over time. You may have been easily able to digest a chana chaat as a kid but over the past few years, you may be feeling gassy after one small serving of it. The same happens with FODMAP tolerance. An IBS patient may be able to tolerate fructans from onions and not tolerate lactose from milk today, but a year down the line they may start tolerating milk and may develop intolerance to some other FODMAP group.

Photo by Sam Lion from Pexels

Thus, regular follow up and FODMAP challenging is necessary to efficiently implement the low FODMAP diet and manage IBS. The low FODMAP diet is still under research, but existing research data gives promising evidence about the efficacy of the low FODMAP diet in the management of IBS.

FODMAP containing foods are safe and nutritious for any healthy individual not suffering from IBS, and dietary restrictions are best avoided unless necessary.

Girija Damle

Dietitian, PFNDAI

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