One of the most common components of any recipe, onions have been called ‘the bedrock’ of our cooking. In all cultures around the world, onion is often the first, or last, ingredient to a dish.
Since onions are so ubiquitous, it creates challenges when starting the low-FODMAP diet. Most of us find it difficult to adapt our favorite recipes, particularly at first.
You have come to the right website! I have over a decade of experience in making things taste delicious, without using high-FODMAP onions.
The trick? Try some of the substitutions that I will outline below.
For help with eating out, see my blog post When the Low-FODMAP Diet isn’t Enough for your IBS; Dr. Rachel’s Suggested Additive Tips and Treatments, and Dr. Rachel’s Low-FODMAP Fast-Food Options (Because Low Doesn’t Have to Mean No)
These alternatives are highly successful at keeping the flavors you love, without sacrificing your tummy. I offer simple suggestions, to account for the budgetary and convenience restraints we all face.
Let’s begin with some background. Onions are aromatics, and part of the genus Allium. They are also a key trigger for those of us with IBS. Onions are part of the fructan group; the final stage of FODMAP reintroduction. They are very high in prebiotics inulin and FOS: substrates that are fermented by gut bacteria, and lead to uncomfortable gas, and bloating.
Notwithstanding, onions still have a suitable low-FODMAP portion size. Lets review how much you CAN have, since that may be adequate for certain recipes.
In some cases, FODMAP values change depending on the part of the onion you consume (in case of scallions), or if the onion is raw, or pickled.
The only true way to check FODMAP food data is to use one, or both, of the scientifically supported apps. These include the Monash Uni app, and the FODMAP Friendly app. I suggest you get both to have constant access to the knowledge you need.
WHITE ONION, raw (white skin)
MONASH FODMAP DATA:
- Low-FODMAP serving size of 10g
FODMAP FRIENDLY DATA:
- Low-FODMAP serving size of 15g
RED ONION (PURPLE), raw
MONASH FODMAP DATA:
- Low-FODMAP serving size of 10g
- Higher amounts contain fructans
FODMAP FRIENDLY DATA:
- Low-FODMAP serving size of 27g
VIDALIA ONION (brown onion), raw
MONASH FODMAP DATA
- Low-FODMAP serving of 22g
FODMAP FRIENDLY DATA
- Low-FODMAP serving size of 26g
SHALLOT, raw
MONASH FODMAP DATA:
- High FODMAP at 75g, ‘recommend avoiding’
- Contains fructans
FODMAP FRIENDLY DATA:
- Not tested
SCALLION OR GREEN ONION (spring onion), BULB
MONASH FODMAP DATA:
- Low-FODMAP serving size of 32g
FODMAP FRIENDLY DATA:
- Low-FODMAP serving of 20g
ONION LARGE, PICKLED IN VINEGAR
MONASH FODMAP DATA:
- Low-FODMAP serving size of 60g
FODMAP FRIENDLY DATA:
- Low-FODMAP serving of 30g
- Maximum serving of 43g
ONION SMALL, PICKLED IN VINEGAR
MONASH FODMAP DATA:
- Low-FODMAP serving size of 3g
FODMAP FRIENDLY DATA:
- Not tested
One of the reasons I was inspired to write my 2 books, was to guide people through the low-FODMAP diet, from Elimination to Personalization. Click this link to see them on Amazon!
Accurate FODMAP diet food lists are an ever-evolving project. They are constantly being modified, with new foods being tested and added all the time. Certain foods have even changed in their reported FODMAP quantities, by having increases, or decreases made to their suggested portion sizes.
Check out these other great posts:
- Dr. Rachel’s Low-FODMAP Garlic Substitutes
- Dr. Rachel’s FODMAP Facts: Are Bananas Low-FODMAP?
- Dr. Rachel’s FODMAP Facts: Are Blueberries Low-FODMAP?
- Dr. Rachel’s FODMAP Facts: Is Cheese Low-FODMAP?
- Dr. Rachel’s FODMAP Facts: Is (Pop)Corn Low-FODMAP?
Below is based on FODMAP data at time of posting
Dr. Rachel’s Note: I highly recommend using a kitchen scale when following a low-FODMAP diet to ensure accurate measurements
When it comes to replacing the flavor of onion, there are several options. Some will replicate the flavor almost exactly, while others are similar, but not identical. You may wish to primarily select one, or many of these options.
Infused Oils
I am a big fan of infused oils in my cooking. When it comes to flavor that is virtually identical, I find that onion and shallot-infused oils are the absolute best.
Many people are surprised to learn that oils infused with onion (and garlic), may be low in FODMAPs. How is that possible? The answer is related to the biochemistry of the FODMAP fructans. These carbohydrates are not fat soluble, so they will not dissolve in an oil base. Flavors will infuse the oil, while leaving behind the triggering carbohydrates. That means, the product is pure fat, and it will be FODMAP free (provided it is properly manufactured and filtered).
However, it is important to note, that the FODMAP will dissolve in a water-based product. So if you put onion in a soup broth, then remove the onion pieces, the FODMAPs from the onion will remain.
Instead, put a tablespoon of onion-infused oil in the soup water, and solve the tummyache!
Several companies produce infused oils, and these are invaluable to my recipes. Amazon sells several varieties (ex: Fody, GarlicGold, Texana) . I typically reduce the amount of regular oil or butter in my recipe, and substitute it for the infused options :).
Read more about garlic here: Dr. Rachel’s Low-FODMAP Garlic Substitutes.
Scallions or Spring Onions (green tips only)
You may have noticed my mention of scallions above. Interestingly, there are differing levels of FODMAPs, depending on what part of the scallion you select.
For the bulb (white portion), FODMAP levels are quite high.
However, the green (stalk) portion, is much lower. It has a less robust onion flavor, but can still provide a savory, slightly peppery taste. Scallions are also very affordable, and easily available.
FODMAP TIP: After using the green portion, take the scallion bulbs (with roots attached) and place them in a glass, with a small amount of water. New green shoots will sprout within a few days making these easily available for your cooking.
Green Scallion Tips:
MONASH FODMAP DATA:
- Low-FODMAP serving size of 75g
- Moderate serving of 97g
- Higher amounts contain fructose
FODMAP FRIENDLY DATA:
- Maximum low-FODMAP serving size portion size of 40g
- Higher amounts contain fructans and GOS
Green onion powder is available for sale in the US, from a specialty FODMAP website. I have not personally sampled this product, so I can’t vouch for the flavor (ex: Gourmend Foods).
Leeks
Similar to green onions, leeks FODMAP content varies based on the part of the vegetable you consume. Leeks are less pungent than onions, but are also in the Allium family. They will provide a sweeter, lighter flavor and are aromatic like an onion.
*Avoid the bulb portion, where a low-FODMAP serving only 14g per Monash, maximum of 47g per FODMAP Friendly
Leeks, Green Leaves Only:
MONASH FODMAP DATA:
- Low-FODMAP serving size of 75g
- Low in FODMAPs to 500g
FODMAP FRIENDLY DATA:
- Maximum low-FODMAP serving size of 82g
Chives
Chives are an amazing option for FODMAP followers. They are VERY low in FODMAPs, and have a mild onion flavor. Both dried, and fresh are suitable.
You may also be able to find chive powder seasoning from speciality spice stores, which (if made only from ground chives) is also low-FODMAP. I own a chive powder seasoning that I find very useful in certain dishes.
MONASH FODMAP DATA (fresh):
- Low-FODMAP serving size of 4g
- ‘Low in FODMAPs up to 500g’
FODMAP FRIENDLY DATA (fresh or dried):
- Nil FODMAPs detected, eat freely
‘Onion-Replacement’ Salts/Seasonings/Powders
There are several commercially available ‘onion replacement’ products for FODMAP followers.
Some are salts with artificial onion flavors (ex: SmokeN’Sanity), some are powders with onion-like flavoring (ex: FreeFOD, Foddies). All are available on Amazon.
Full disclosure, I have not personally tried any of these options. The reviews are mixed, with some people stating they are great alternatives, and others finding there is a bad texture, aftertaste, or too salty flavor depending on the product. They are also somewhat expensive, unless you plan to use them often.
Asafetida and Other Herbs:
Asafetida is a spice used in Asian and Indian cuisine. It has a pungent aroma, and releases an onion-like flavor with cooking. It is easily available in stores and online. Asafetida (Asafoetida) tested ‘low in FODMAPs’ by MONASH, and was found to contain ‘nil FODMAPs’ by FODMAP Friendly.
Other tools I love in my kitchen include a variety of fresh herbs, like ginger, rosemary, oregano, turmeric, thyme, chili, and others. I have found that I don’t really enjoy the flavor of onion anymore, as I think it overwhelms the entire dish, and lingers on my palate long after eating. Since I also have GERD, this can be unpleasant.
Most dried and fresh herbs are very low in FODMAPs, and can be used freely in your cooking.
As you can see, there are several ways to add onion flavor your recipes without using onion! These are very easy to incorporate, and will open up the options for your enjoyment.
My favorites are infused oils, scallion tips, and fresh herbs for my recipes. I have also invested in chive powder since it lasts a long time.
When you are ready for the reintroduction phase, you will perform a challenge with onion. Since I am in the personalization FODMAP stage, I have tried to reintroduce onion, without much success. Regardless, personal triggers are variable. You may find that you can tolerate larger portions than those described. Learn your tolerance, and adjust accordingly.
Here are some delicious low-FODMAP recipes that use onion substitutes:
- Low-FODMAP 30-Minute Korean Beef; Gluten-free, Dairy-free
- Creamy Low-FODMAP Green Bean Casserole; Gluten-free, Vegetarian
- Low-FODMAP Chicken Bacon Ranch Casserole; Gluten-free
- Low-FODMAP Sheet Pan Asian Ginger and Lemon Chicken; Gluten-free, Dairy-free
- Easy Low-FODMAP Cheesy Scalloped Potatoes; Gluten-free, Vegetarian
For more on the FODMAP diet, check out my amazing posts:
- Dr. Rachel’s Low-FODMAP Diet 5-Day Meal Plan; Recipes and More (IBS-friendly!)
- Dr. Rachel’s Low-FODMAP Fast-Food Options (Because Low Doesn’t Have to Mean No)
- Low-FODMAP Options at Starbucks
- Dr. Rachel’s Low-FODMAP Grocery Shopping List; IBS-friendly, Gluten-free
- Dr. Rachel’s Guide to Starting the Low-FODMAP Diet
Be healthy and happy,
Rachel Pauls, MD
