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The Lowdown on FODMAPs

The Lowdown on FODMAPs

The Lowdown on FODMAPs
You may have been hearing about FODMAPs or FODMAP diets for a while now. If you’ve been wondering what the heck that’s all about, wonder no more.

FODMAP is an acronym for Fermentable Oligo-, Di-, and Mono-saccharides And Polyols. That’s quite a mouthful! FODMAP is easier to say (and remember) so let’s stick with that.

All of the FODMAP nutrients are in the carbohydrate family.

F = Fermentable. Fermentable carbohydrates are sugars that are broken down and digested by the friendly bacteria in our intestines, which produces gas as a byproduct.

O = Oligosaccharides. These are short chains of carbohydrate molecules that are linked together. For example, Fructans, a chain of fructose (fruit sugar) molecules are a type of oligosaccharides that humans are not able to break down properly.

D = Disaccharides. A disaccharide is two carbohydrate molecules linked together. For example, lactose, the naturally occurring sugar found in milk, is made up of glucose and galactose.

M = Monosaccharides. These are carbohydrate molecules comprised of a single sugar. For example, fructose, the naturally occurring sugar in fruit, is a monosaccharide.


P = Polyols. Polyols, also known as sugar alcohols, are a type of carbohydrate that humans can only partially digest and absorb. For example, sorbitol and xylitol are sugar alcohols often used as low-calorie sweeteners.

FODMAPs are not inherently harmful, and most people tolerate all or most of them, but some people experience varying degrees of gastric distress (bloating, abdominal pain, gas, diarrhea, constipation) when they consume FODMAP containing foods. These symptoms are common in people who have irritable bowel syndrome, but many people without a formal diagnosis also feel better when eliminating some or all FODMAPs containing foods from their diets. It is also increasingly thought that folks suffering from non-celiac gluten intolerance, which doesn’t have a formal diagnosis, are in fact FODMAP intolerant.

Although FODMAPs don’t cause digestive disorders, exposure to them can trigger symptoms in those with sensitive or troubled digestive systems. When FODMAPs reach the small intestine, they draw fluid into the bowel, where normal gut bacteria ferment the FODMAP carbohyrate molecules, producing gas. The liquid and gas stretch the intestine, causing pain and discomfort and sometimes triggering other IBS syndromes in folks who suffer from it.

So where are FODMAPs found?

Some high FODMAP foods include:
-bell peppers
-soft cheeses
-corn syrup

Of course this is far from an exhaustive list! And there are plenty of low FODMAP alternatives.

Some low FODMAP foods include:
-winter squash
-lactose free milk
-hard cheeses
-maple syrup

Help! I think I’m FODMAP sensitive!

If you think that FODMAPs may be the key to your tummy troubles, speak to your health care provider about an elimination diet. I always cringe when I hear about people attempting “rogue” elimination diets on their own, as they can be a bit tricky. And if not conducted properly, an elimination diet can be misleading, and in some extreme cases, harmful.

A FODMAP elimination diet is considered to be a “learning diet.” It isn’t intended to be a life-long elimination diet the way a gluten-free diet would be for celiacs. Rather, with the help of your health care provider, you eliminate high FODMAP foods for 4-6 weeks, and then work through a carefully controlled re-introduction program while monitoring your symptoms. Many times a FODMAP elimination diet offers a therapeutic “reset” to your digestive system, and some folks are able to go back to eating all FODMAP containing foods. Others may choose to continue to eliminate certain trigger foods, but are able to reintroduce others.

What’s important to remember here is that many high FODMAP foods are incredibly healthy and are beneficial to digestive health overall (e.g. lentils, apples, avocados) and if you’re able to reintroduce them, you should. However if there merest whiff of garlic is sending you into the throes of gastric distress, that should probably stay off the table.

So, there you go. FODMAPs in a nutshell. Happy, healthy eating to you all!

Wheat photo via Shutterstock.

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  • Reply
    November 4, 2015 at 12:47 pm

    fascinating! i’ve always been curious about the fodmap hoopla. thanks for the brief but thorough description.

    • Reply
      Katie Trant
      November 4, 2015 at 3:38 pm

      Glad to have cleared things up for you!

  • Reply
    November 4, 2015 at 1:30 pm

    I don’t think corn is a high fodmap food (corn syrup, yes, corn, no). Stanford has it listed as low…

    • Reply
      Katie Trant
      November 4, 2015 at 3:41 pm

      Corn seems to be one of those outliers that appears on both lists. Many sources list corn as listed as “in small doses only (1/2 cob or less), if tolerated,” which is why I listed it as I did. But the level of processing does seem to impact the tolerability of corn, and yes, high fructose corn syrup is definitely on the high FODMAP list!

  • Reply
    November 4, 2015 at 4:26 pm

    How interesting -I’d never heard of this! I’m sure I’ll see it everywhere now that I’ve learned about it.

  • Reply
    Diana G
    November 5, 2015 at 10:18 am

    spelt is questionable.

  • Reply
    Diana G
    November 5, 2015 at 10:20 am

    also beets are allowed in only very limited amounts. You can get away with having more corn tortilla chips than you can beets.

    • Reply
      Katie Trant
      November 5, 2015 at 11:08 am

      True. I usually advise that people stay off all grains for 4-6 weeks, but I’ll try re-introducing small amount of spelt before other wheat products. Beets, like corn, seem to vary quite a lot from case to case.

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