If you’re like most people, you’ve heard all about the dangers of gluten but have no idea what a FODMAP is.
And if you regularly experience gastrointestinal issues when you eat–gassiness, bloating, nausea, abdominal pain, cramping, belching, reflux, fatigue, diarrhea and/or constipation–then you need to read this article.
In fact, research has found that a low-FODMAP diet improves symptoms in 74% of patients with Irritable Bowel Syndrome (IBS) and is the real culprit behind what many people think is non-celiac gluten sensitivity (NCGS).
So, let’s look at what FODMAPs are, why they can be so troublesome, and how you can assess your sensitivity to them and, if necessary, eliminate them from your diet.
What Is a FODMAP?
FODMAP stands for…deep breath…Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols.
But just for the sake of thoroughness, let’s unpack this acronym one word at a time.
It starts with fermentable because these carbs ferment easily in the colon.
Then come three types of saccharides, which are sugar molecules found in foods.
Monosaccharides are often called simple sugars because they have a very simple structure. Mono means one and saccharide means sugar. So, one sugar.
The monosaccharides are…
Glucose is a type of sugar also known as blood sugar, which is found in our blood and produced from the food we eat (most dietary carbohydrates contain glucose, either as the sole form of sugar or combined with the other two simple sugars given above).
When people talk about “blood sugar levels,” they’re talking about the amount of glucose floating around in the blood.
Fructose is a type of sugar naturally found in fruit, and also found in processed products like sucrose (table sugar) and high-fructose corn syrup, both of which are about 50% fructose and 50% glucose.
Fructose is converted into glucose by the liver and then released into the blood for use.
Galactose is a type of sugar found in dairy products and it’s metabolized similarly to fructose.
Oligosaccharides are molecules that contain several monosaccharides linked together in chain-like structures. Oligos is Greek for a few, so a “few” sugars.
These sugars are one of the components of fiber found in plants, which our bodies are able to partially break down into glucose (leaving the fibrous, indigestible parts behind to do good things in our guts).
Many vegetables also contain fructo-oligosaccharides, which are short chains of fructose molecules. These are metabolized accordingly (the “chains” are broken and the individual fructose molecules are then converted into glucose for use).
Another common form of oligosaccharide that we eat is raffinose, which is comprised of a chain of galactose, glucose, and fructose (called a trisaccharide), and which can be found in beans, cabbage, brussels sprouts, broccoli,asparagus, other vegetables, and whole grains.
Galactooligosaccharides round out the list of oligosaccharides, and are short chains of galactose molecules. These are indigestible but play a role in stimulating healthy bacteria growth in the gut.
Disaccharides are molecules that’s composed of two monosaccarides .
Two common examples of disaccharides are milk sugar (lactose), which is made from glucose and galactose, and table sugar (sucrose), which is made from glucose and fructose.
Last but not least is the polyols, which are also called sugar alcohols, and which are a group of low-calorie, sweet carbs that can be substituted for table sugar.
The most popular polyols are erythritol, maltitol, xylitol, and sorbitol.
Now, if you look over all the foods I just listed again, you’ll quickly understand why people with a FODMAP sensitivity are often baffled by their condition.
Namely, it goes far beyond wheat and wheat products, which are the dietary scapegoat du jour.
FODMAPs are ubiquitous in the modern Western diet, and people with a FODMAP sensitivity can work hard to eat an extremely “clean” diet replete with fruit, veggies, legumes, and the like…only to suffer for it.
They never suspect that the problem lies in the fact that their bodies just can’t properly digest and absorb all the “healthy” foods they’re eating.
For example, some of the foods most likely to light the FODMAP fuse include…
- Brussels sprouts
- Snow peas
- Processed grains and cereals
Furthermore, FODMAPs are found in seemingly innocent condiments, canned and bottled sodas, beverages such as fruit juice, and much more.
Research also shows that some people experience non-optimum reactions only when certain amounts of FODMAPs are eaten, making it even harder to make sense of their circumstances.
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Why Are Some People Sensitive to FODMAPs?
In the case of oligosaccharides, humans simply lack the enzymes to break them down.
That means that when these carbs reach the colon, they’re still relatively intact, which can cause GI distress.
The two main offenders here are fructans and galactans.
Fructans are a form of fructose found in various fruits, vegetables, legumes, and grains; and galactans are a form of galactose found primarily in legumes.
In the case of disaccharides, the most troublesome one is, by far, lactose (a sugar found in mammals’ milk).
While the body is able to produce an enzyme to break down lactose–lactase—many adults no longer do, hence the prevalence of lactose intolerance.
Out of the three monosaccharides, fructose gives people the most grief.
Once it reaches your intestines, it can draw in water and cause intestinal swelling, which tells the nervous system that something is wrong.
Research shows that this can even happen in healthy, symptom-free individuals.
In fact, when a large dose of fructose is consumed by itself (e.g. 50 grams) the majority of healthy individuals will malabsorb at least some of it and may experience symptoms normally associated with a fructose sensitivity.
(This highlights one of the problems with the pervasiveness of high-fructose corn syrup in our foods.)
Polyols, which are found in many sugar-free foods, candies, and gums, are only partially digested and absorbed in the small intestine, and once they reach the large intestine, can result in bloating and laxative effects.
Who Should Avoid FODMAPs?
If you have any of the following conditions, then a low FODMAP diet may help reduce your symptoms.
- Gastrointestinal distress
- Lactose/fructose malabsorption
- Inflammatory bowel disease (Crohn’s, ulcerative colitis)
- Irritable bowel syndrome (IBS)
- A suspected non-celiac gluten sensitivity (NCGS)
Many of these “disorders” disrupt quality of life and don’t respond well to medication, so alternate approaches of coping are often welcome.
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How to Know If You’re Sensitive to FODMAPs
While simple breath tests claim (with questionable accuracy) to determine FODMAPs sensitivity, only a few of the offenders can be tested (fructose, sorbitol, and lactose).
The most reliable way to assess your gut’s relationship with FODMAPs is a comprehensive elimination diet.
An elimination diet is a strategic approach to reducing and reintroducing FODMAPs in your diet, closely monitoring your body to learn how each food affects you.
A typical FODMAPs elimination diet lasts 6 to 8 weeks and looks like this:
- First, you reduce overall FODMAPs intake
You can do this by substituting high-FODMAP foods with lower-FODMAP options or by reducing the total FODMAP load consumed at each meal.
This phase should last around 4 weeks, or until your symptoms are under control.
- Next, you systematically reintroduce FODMAPs
Here you begin to reintroduce FODMAPs one at a time, paying close attention to how your body reacts.
A detailed food and symptoms log is the only way to get a good look at what is causing your problems, so attentiveness and patience is key.
- Finally, you tweak and expand your diet
In the last step, you work to gradually increase your diet to include FODMAPs at tolerated levels.
You may find that only one or two foods are responsible for most of your symptoms, and many people (joyously) discover they’re still able to eat their favorite foods in moderation.
If that sounds like a huge headache, I understand.
Remember, though, that it’s a one-time affair that will help you determine the optimum FODMAPs levels for your body.
How to Eat a Low-FODMAP Diet
More and more nutritionists and physicians are also beginning to recommend low-FODMAP diets for diagnostic and therapeutic purposes, so there is likely support out there if you want a hands-on approach.
And if you’re worried that going low-FODMAP will leave you with nothing good to eat, fret not.
Here are just a few of my favorite low-FODMAP foods:
- Fruits: Banana, orange, mandarin, grapes, melon.
- Grains: Gluten-free bread and sourdough spelt bread, rice bubbles, oats, gluten-free pasta, rice, quinoa.
- Dairy: Lactose-free milk, lactose-free yogurt, hard cheese.
- Nuts/seeds: Almonds (<10 nuts), pumpkin seeds.
- Protein: Meats, fish, chicken, Tofu, tempeh.
- Vegetables: Alfalfa, bean sprouts, green beans, bok choy, capsicum (bell pepper), carrot, chives, fresh herbs, choy sum, cucumber, lettuce, tomato, zucchini.
- Other snacks: Gluten-free biscuits, rice cakes, corn thins.
You can also make it easier on yourself by creating an individualized list with your FODMAP-friendly preferences in mind.
It’s also a good idea to prepare your meals and snacks yourself to keep a close eye on ingredients. Remember–FODMAPs are lurking in many unexpected places.
Finally, once you have pinpointed the FODMAP(s) you’re most sensitive to, you can start taking digestive enzyme supplements aimed at breaking them down.
This “targeted” approach to enzyme supplementation can significantly reduce symptoms.
It’s also worth noting that many high-FODMAP foods are also very nutritious. This is why you don’t necessarily want to follow a low-FODMAP diet forever, even when you’re sensitive to these foods.
Thus, the goal isn’t to permanently ban FODMAPs from your life–it’s to find your body’s “happy medium” between all-out FODMAP indulgence and strict abstinence, where nutrition is balanced and symptoms are all but eliminated.
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The Bottom Line on the Low-FODMAP Diet
Unlike the many fad diets that come and go, the low-FODMAP diet is a legitimate, science-based strategy for improving your gut health and overall well-being.
If you generally don’t experience any stomach troubles after eating, then you don’t have any need for it.
If you do, though, and especially if you think you have a gluten sensitivity, then a low-FODMAP lifestyle might make all the difference.
What’s your take on the low-FODMAP diet? Have anything else to share? Let me know in the comments below!
+ Scientific References
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- Biesiekierski, J. R. (2014). Fructose-induced symptoms beyond malabsorption in FGID. United European Gastroenterology Journal, 2(1), 10. https://doi.org/10.1177/2050640613510905
- Franco-Robles, E., & López, M. G. (2015). Implication of Fructans in Health: Immunomodulatory and Antioxidant Mechanisms. The Scientific World Journal, 2015. https://doi.org/10.1155/2015/289267
- DK, O., SB, M., JS, B., SJ, S., PM, I., JR, B., S, S., PR, G., & JG, M. (2010). Manipulation of dietary short chain carbohydrates alters the pattern of gas production and genesis of symptoms in irritable bowel syndrome. Journal of Gastroenterology and Hepatology, 25(8), 1366–1373. https://doi.org/10.1111/J.1440-1746.2010.06370.X
- Muir, J. G., Rose, R., Rosella, O., Liels, K., Barrett, J. S., Shepherd, S. J., & Gibson, P. R. (2009). Measurement of short-chain carbohydrates in common Australian vegetables and fruits by high-performance liquid chromatography (HPLC). Journal of Agricultural and Food Chemistry, 57(2), 554–565. https://doi.org/10.1021/JF802700E
- PR, G., JS, B., & JG, M. (2013). Functional bowel symptoms and diet. Internal Medicine Journal, 43(10), 1067–1074. https://doi.org/10.1111/IMJ.12266
- GT, M., H, S., & S, M. (2008). Bacterial metabolism and health-related effects of galacto-oligosaccharides and other prebiotics. Journal of Applied Microbiology, 104(2), 305–344. https://doi.org/10.1111/J.1365-2672.2007.03520.X
- Stanford Health Care. (n.d.). Low FODMAP Diet | Stanford Health Care. Retrieved August 11, 2021, from https://stanfordhealthcare.org/medical-treatments/l/low-fodmap-diet.html
- JR, B., SL, P., ED, N., O, R., JG, M., & PR, G. (2013). No effects of gluten in patients with self-reported non-celiac gluten sensitivity after dietary reduction of fermentable, poorly absorbed, short-chain carbohydrates. Gastroenterology, 145(2). https://doi.org/10.1053/J.GASTRO.2013.04.051
- PR, G., & SJ, S. (2012). Food choice as a key management strategy for functional gastrointestinal symptoms. The American Journal of Gastroenterology, 107(5), 657–666. https://doi.org/10.1038/AJG.2012.49
- Biesiekierski, J. R., & Iven, J. (2015). Non-coeliac gluten sensitivity: piecing the puzzle together. United European Gastroenterology Journal, 3(2), 160. https://doi.org/10.1177/2050640615578388