Low-down on the Low FODMAP Diet

Low-Down on the Low FODMAP Diet: What’s It All About & Who Is It For?

Blog, Functional Nutrition & Holistic Health Articles, IBS / April 16, 2023

The “Low-Down on the Low FODMAP Diet” article was originally written by dietetic intern & functional nutritionist Krista Wale, B.S. (nutritional sciences & dietetics), and it was edited, revised, & updated by Jenna Volpe, RDN, LD, CLT.

It’s possible you’ve heard the term “FODMAPs” –  along with some hype about the low FODMAP diet circulating in the gut health space, especially if you’re suffering from irritable bowel syndrome (IBS) or small intestinal bacterial overgrowth (SIBO). 

But what the heck does FODMAP stand for, and is the low FODMAP diet really all that and a bag of chips for IBS sufferers? (Pun intended.)

In this article you’ll learn what FODMAPs are, which foods are high and low in FODAMPs (plus a sample one-day meal plan), who can benefit from a low FODMAP diet, and the pros and cons of this very specific and unique gut health nutrition protocol.

Disclaimer: this article was written for informational and educational purposes. This article is not meant to replace medical advice or nutrition advice from licensed, qualified healthcare providers. Make sure you’re working with a doctor and registered dietitian if you’re navigating gut issues of any kind!

What does “FODMAP” stand for? 

FODMAP is a crazy-sounding acronym which actually stands for “fermentable oligosaccharides, disaccharides, monosaccharides and polyols”.  These are specific types of constituents in foods that tend to trigger unwanted symptoms in many people with IBS/SIBO.

It may sound confusing and complicated at first, but it doesn’t have to be!  Let’s break it down…

What exactly are FODMAPs?!

To be more specific (beyond the acronym), FODMAPS are poorly absorbed, highly fermentable, short-chain carbohydrates which meet some/all of the following criteria:

Fermentable 

  • These constituents all ferment when they come in contact with certain types of microbes in your gut, producing gasses as a bi-product. 

Oligosaccharides  

type of carbohydrate made up of a few different types of sugars. 

    • (“Oligo-” = few)

Disaccharides 

  • A carbohydrate made up of two sugars.
    • (“Di-” = two)

Monosaccharides

  • A type of carbohydrate made up of one sugar.
    • (“Mono-” = one)

And…

Polyols

  •  A type of short-chain carbohydrate found in certain fruits, veggies, and sugar alcohols.

FODMAPs and IBS / SIBO

FODMAPs aren’t generally digested well, but for people with a healthy gut, high-FODMAP foods can usually move through the digestive tract without causing discomfort. (In fact, ironically, many types of high FODMAP foods and herbs happen to also be prebiotic foods/herbs!)

However, for those of us struggling with a compromised gut (such as in cases of IBS or SIBO), it’s difficult to properly digest foods that are high in FODMAPs. In these cases, high FODMAP foods may trigger or exacerbate symptoms like:

  • Bloating
  • Gas
  • Abdominal pain
  • Distention 
  • Changes in bowel regularity (i.e. constipation or diarrhea) 

How it works

Undigested or poorly digested FODMAPs from the foods we eat will travel down into the small intestine.  In the intestines, there are sometimes “pathogenic” (bad, unhealthy) microbes (which are generally more likely to live in the digestive tracts of people with IBS/SIBO) which will then feast on these FODMAPs.

When the bad bacteria consume the FODMAPs in high-FODMAP foods, it leads to fermentation and methane/hydrogen gas production, ultimately triggering the types of IBS symptoms mentioned above. 

In some cases, when the undigested FODMAP particles reach the colon, this can also cause excess water to get pulled into the colon (by osmosis), which can then result in symptoms of diarrhea in people with diarrhea-predominant IBS (“IBS-D”) or hydrogen-dominant SIBO.

The types of FODMAPs in food 

There are 5 categories of FODMAPs found in high-FODMAP foods:

  • Fructose
  • Lactose
  • Fructans
  • Galactans 
  • Polyols

Fructose 

Fructose is a monosaccharide (type of simple sugar) found in certain types of fruits and fruit juices, and certain high FODMAP sweeteners like honey and agave nectar.

  • Not everyone with IBS/SIBO has a fructose intolerance, but it’s still relatively common. 
    • If you suspect you do have a fructose intolerance, you may want to consider running a fructose breath test and/or keep track of your food intake and IBS symptom patterns via an IBS food diary!

Lactose 

Lactose is a type of disaccharide sugar found in certain dairy foods like milk and ice cream.

  • Contrary to what most people believe, not all types of dairy contain lactose!  For this reason, many people with a lactose intolerance can usually still enjoy hard cheese and butter/ghee in moderation without any issues.  (Yogurt is hit or miss – it contains lactose but the probiotics in yogurt usually help to pre-digest it for us.)

Fructans 

Fructans are constituents found in wheat products such as bread and pasta, as well as in some veggies like garlic and onions.  

  • Many people who believe they have a gluten intolerance actually have a fructan intolerance!  (If you’d like to learn more about this, you can read about the differences between wheat vs gluten here.)

Galactans

These are a type of difficult-to-digest carbohydrate most often found in beans and certain types of fruit/veggies.

Polyols 

These are found in sugar alcohols like mannitol and sorbitol, and they’re also naturally occurring in some fruits (like apples, pears, peaches and apricots) & certain veggies like mushrooms. (1)

Which foods are high in FODMAPs? (2)

The following list is not exhaustive, but it may help provide you with some clarity as you navigate your IBS food triggers.

This is not a list of foods to avoid but rather a list of foods you can refer back to, while looking for patterns via food-symptom journaling in an IBS food diary.

Fruits 

High FODMAP fruits are those which contain high amounts of fructose and/or polyols in relatively small quantities, such as:

  • Apples
  • Apricots
  • Blackberries
  • Cherries
  • Dates
  • Grapes (if more than 10 at a time)
  • Mango
  • Nectarines
  • Papaya
  • Peaches
  • Pears
  • Plums 
  • Prunes
  • Watermelon
  • High concentration of fructose from canned fruit, dried fruit, or fruit juice

Veggies

High FODMAP veggies contain significant amounts of fructans and/or polyols:

  • Artichokes (“sunchokes”)
  • Asparagus
  • Beets (if more than 1/2 cup serving)
  • Brussels sprouts
  • Cauliflower
  • Celery
  • Garlic
  • Leeks
  • Mushrooms
  • Okra
  • Onions
  • Peas
  • Shallots
  • Snow peas (more than 1/2 cup)
  • Sugar snap peas (if 7 or more)

Grains/starches

The following grains and starches are high in fructans, and are not usually well tolerated by many people with IBS/SIBO:

  • Products that are made with wheat and/or “all purpose flour” (read the ingredient list to verify):
    • Breads
    • Bagels
    • Cereals 
    • Crackers
    • Muffins
    • Pastries
    • Snack foods (Goldfish, CheezIts, etc.)
  • Barley
  • Couscous
  • Farr
  • Rye
  • Semolina

Fats/oils and condiments

  • Almonds (if more than 10)
  • Almond butter (if more than 1 to 2 Tablespoons)
  • Almond flour (if more than 1/2 cup)
  • Avocado
  • Cashews / cashew butter
  • Hazelnuts (if more than 10)
  • Hazelnut butter (if more than 1 to 2 Tablespoons)
  • Pistachios
  • Salad dressings and marinades with high FODMAP ingredients (i.e. Caesar dressing, Italian dressing, BBQ sauces sweetened with honey/high fructose corn syrup, etc.)

Proteins

  • Beans (black, kidney, lima, pinto, edamame) if more than 1 Tablespoon
  • Chickpeas (more than 1/4 cup serving)
  • Lentils
  • Split peas
  • Soy products (tofu, tempeh, miso, “soy protein isolate”, soy milk)
  • Any types of meat/poultry or pork marinated in a high FODMAP sauce/dressing (i.e. one that contains garlic, onion powder, honey, agave, high fructose corn syrup, etc.)

Dairy and dairy alternatives

  • Milk (cow, goat, sheep)
  • Buttermilk
  • Yogurt
  • Cream
  • Soft cheeses (cream cheese, cottage cheese, ricotta)
  • Sour cream 
  • Soy milk
  • Oat milk (more than 1/4 cup)

Sweeteners

  • Agave
  • Dates / date sugar / date syrup
  • Fructose
  • High fructose corn syrup
  • Honey
  • Isomalt
  • Maltitol
  • Mannitol
  • Molasses
  • Sorbitol
  • Xylitol

Sweets/desserts

Any sweet treats made with any of the above high FODMAP sweeteners or wheat/all-purpose flour (cookies, cake, etc.) are considered to be high FODMAP:

  • Cake
  • Cookies
  • Custard
  • Ice cream

What about high FODMAP herbs/spices?

The only high FODMAP herbs worth noting are garlic, garlic powder, and onion powder – or any spices blends that contain those ingredients.  

You may also want to steer clear of the white parts of scallions, if you find that garlic and onions bother you.

Which foods are low in FODMAPs? (2, 3)

Okay, so now you’ve got a comprehensive list of which foods may be most likely to trigger your IBS symptoms… but what about the ones that are LEAST likely to trigger your IBS?  

Enter:  low FODMAP foods!  

(As a friendly reminder, this list of low FODMAP foods is general and not customized to meet your individual needs.  However,it may serve as a helpful starting point of reference and “nutritional backbone” to give you some extra clarity and education on your journey.)

Fruits

  • Banana (1/2)
  • Blueberries (1/2 cup or less)
  • Cantaloupe
  • Clementines
  • Grapes (10 or less)
  • Grapefruit (1/2 small)
  • Honeydew melon (1/2 cup or less)
  • Kiwi
  • Lemon
  • Lime
  • Oranges
  • Pineapple
  • Pomegranate seeds (1/3 cup or less)
  • Raspberries
  • Strawberries
  • Tangerines / tangelos

Veggies

  • Arugula
  • Bamboo shoots
  • Bell peppers
  • 1/4 cup cooked Broccoli
  • Bok choy
  • Carrots
  • Collard greens
  • 1/2 cup coked cabbage
  • Corn (half a cob)
  • Eggplant
  • Green beans
  • Kale
  • Lettuce
  • Parsley
  • Parsnips
  • Potatoes
  • Radicchio 
  • Scallions (green parts only)
  • Spinach, baby
  • Squash – butternut, winter, & summer squash
  • Sweet potato
  • Swiss chard
  • Tomato
  • Turnip
  • Water chestnuts
  • Zucchini

Grains/starches

  • Amaranth
  • Cassava flour (up to 2 Tablespoons)
  • Corn flour
  • Corn pasta
  • Potatoes
  • Quinoa
  • Rice (basmati, black, brown, jasmine, wild, white, yellow)
  • Rice noodles
  • Rice pasta
  • Tapioca

Fats/oils

Technically, all oils are considered low in FODMAPs since they don’t contain any carbohydrates.  

Either way, we encourage you to lean on less processed, healthier oils versus the highly processed omega-6 oils like canola, soybean, or corn/vegetable oil. 😉

  • Almond oil
  • Avocado oil
  • Butter/ghee
  • Canola oil 
  • Coconut milk (homemade or free of fillers) 
  • Coconut oil
  • Corn oil 
  • Flaxseed oil
  • Grapeseed oil
  • Olives
  • Olive oil (extra virgin)
  • Peanut oil
  • Rice bran oil
  • Safflower oil
  • Sesame oil
  • Sunflower oil
  • Walnut oil  

Nuts/seeds

  • Almonds (limit 10)
  • Almond butter
  • Brazil nuts
  • Chestnuts
  • Chia seeds
  • Flax seeds (ground)
  • Hazelnuts (limit 10)
  • Justin’s hazelnut butter
  • Macadamia nuts
  • Peanuts / natural peanut butter
  • Pecans
  • Pecan butter
  • Pepitas (pumpkin seeds)
  • Pine nuts
  • Sesame seeds
  • Sunflower seeds (limit 3 Tablespoons)
  • Sunflower seed butter (limit 1 to 2 Tablespoons)
  • Tahini (sesame paste) – up to 1 Tablespoon
  • Walnuts
  • Walnut butter

Proteins

Protein foods like meats, seafood, poultry, pork, and eggs naturally do not contain any carbohydrates – so they’re considered inherently free of FODMAPs. 

However, pay attention to any sauces, dressings or marinades that may contain high FODMAP ingredients.  

Sweets

Any desserts which are made with only low FODMAP ingredients (starches, sweeteners, and fats) can meet criteria for being low FODMAP.  

However, it’s important to keep in mind, just because a sweetener meets criteria for being low in FODMAPs doesn’t automatically make it healthy for your gut – some low FODMAP sweeteners can still disrupt other types of gut microbes related to dysbiosis (an underlying contributor of IBS).

Low FODMAP diet sample menu 

Okay, so now that you have a list of all the foods high and low in FODMAPs, what does a low FODMAP meal plan look like?  

Here’s an example of what a full day can look like on a low FODMAP diet:

When can someone benefit from a low FODMAP diet?

If you’re struggling with digestive issues, you and your healthcare team may need to do some detective work in order to find what’s triggering your symptoms. 

  • A low FODMAP elimination diet is one way to do this, since up to 75% of IBS sufferers in research studies have reported to feel better on a low FODMAP diet in 6 weeks or less. (4)

On the other hand, more than 1/3 of people with IBS turn out to test positive for SIBO, according to the Journal of gastroenterology. (5).  

  • If you have IBS and you find that you feel better on a low FODMAP diet, it may be worth running a SIBO test alongside a doctor and functional dietitian nutritionist, to get more clarity on what’s going on in your gut.

Is a low FODMAP diet enough to resolve IBS/SIBO?

A low FODMAP diet may provide temporary relief by removing troublesome foods that are triggering your symptoms.  However, this diet is not enough as a stand-alone intervention for IBS or SIBO, unfortunately. 

  • Elimination of triggering foods intolerances (such as FODMAPs) is only part of phase one of the five-part 5R protocol for gut repair. 

Pros and cons of a low FODMAP diet

Since one size doesn’t fit all, you may want to review the potential benefits and risks before embarking on a low FODMAP diet – even if you suffer from IBS/SIBO.

Potential benefits

  • Could help provide digestive relief from unwanted IBS/SIBO symptoms
  • May serve as a great nutritional backbone on a gut-healing journey

Downsides & possible contraindications

It doesn’t work for everyone

The low FODMAP diet requires a lot of work and planning, and not everyone with IBS finds relief on a low FODMAP elimination diet.  

Even though it’s considered evidence-based, this diet is still (on some level) a form of guesswork.

Not a cure for IBS/SIBO

Even if this diet helps manage and reduce symptoms, the low FODMAP diet doesn’t address the underlying root-causes of IBS/SIBO – it is only one piece of the puzzle.

  • You’ll need a holistic and multidimensional approach in order to heal your gut. 

Not customized

Since everyone’s body is unique, it could still be difficult to pinpoint exactly which foods are YOUR triggers. 

FODMAPs are a type of food intolerance, but you could also be dealing with food allergies and/or food sensitivities.  

Too restrictive

Many foods include FODMAPs.  This diet (like other types of IBS diets)  is very restrictive, and can get stressful and overwhelming pretty fast.

Don’t go on a low FODMAP diet without working alongside a registered dietitian, and it’s not a good idea don’t go down this path if you have an eating disorder or struggle with disordered eating.  

Missing out on key nutrients 

High FODMAP foods make up a substantial proportion of a normal healthy diet.  FODMAPs are also a main food source of prebiotics.  

It’s easy to develop nutritional deficiencies and difficult to consume enough prebiotics while following a low FODMAP diet.

Not supposed to be long-term

This diet is meant to be followed only for a few months to help you relieve symptoms and “re-inoculate” your gut microbiome while repairing your gut lining.  This is not a long-term solution for IBS.  

When you address your gut issues properly, you should eventually be able to start reintroducing and tolerating high FODMAP foods again in your diet.

Learn more!

If you’d like to learn more about FODMAPs, IBS, and/or SIBO, make sure to check out the following resources:

Low FODMAP diet: the bottom line

“FODMAPs” are poorly absorbed, fermentable, short-chain carbohydrate foods that most people with a healthy gut can digest without consequences. 

If you have compromised digestion, IBS or SIBO, eating foods high in FODMAPs can likely trigger or exacerbate unwanted symptoms such as gas, bloating, pain and changes in bowel regularity. 

Leaning on a low FODMAP diet may provide relief of symptoms, but there are other steps that need to be taken. However, a low FODMAP diet is not the solution to gut issues.

FODMAPs are not the root cause of gut issues and shouldn’t be avoided forever. In fact, FODMAPs foods can and should eventually be a part of a nutritious, balanced diet, even among those with IBS/SIBO.

If you’re struggling with gut issues, it’s crucial that you heal and repair your gut at the root-cause level.

Enrolling in the Complete Gut Repair Roadmap online program and working with a dietitian who specializes in IBS/SIBO could help improve your digestive health and increase your overall chance for success!

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