Onion substitute fodmap
| | |

Onion substitutes on the FODMAP diet

Onion, a staple for many meals. Many people who follow the FODMAP diet, have a hard time keeping onion out of their diet. But not to worry! There exist plenty of alternatives to replace your onion with. So let’s dive in.

onion substitute fodmap

FODMAP and Onion

To start, let’s talk about why onions need to be avoided during the FODMAP diet.
Onion in itself can already be a trigger for Irritable Bowel Syndrome (IBS). It’s well known for the gas production it can cause. But since the discovery of FODMAPs (click here to read more about FODMAPs) it became apparent that there are substances in onions that can cause bloating, diarrhea, or constipation.

These triggering substances are the FODMAP-oligosaccharides. Oligosaccharides are long-chain carbohydrates that are hard to digest. On the other hand, our gut bacteria (microbiome) don’t have any problems digesting them. This can lead to gas production and other byproducts from bacterial fermentation that influence our gut motility and can cause symptoms.

Unlike many other products that contain FODMAPs, onion doesn’t even have a ‘safe’ low FODMAP portion size. This means that even very small amounts of onion can give you symptoms and should be avoided. The Monash University even adds a warning for onion powders that are often being used in products. So bring that magnifying glass to the store with you, and read all the ingredient labels!

Replace Onion on the FODMAP diet

If you want to follow a recipe, when you’re doing the FODMAP diet, it is smart to adjust the recipe to your diet. Luckily there are quite a few tasty replacements for onion, so your meal will still taste good!

Chives are completely low FODMAP and free to use at any portion size. Add the chives on top of your meal to add an onion-like flavor.

Leek (green tops). Leek is lower in FODMAPs than onion is, but the green tops are low FODMAP up to 75 grams. Be careful not to add too much of the white parts of the leek, this adds up in FODMAP-fructans quite fast.

Spring onion (green tops). The green tops of spring onion are completely low FODMAP at any portion size. Do avoid the white parts, because they contain FODMAP-fructans.

Asafoetida is a herb with a strong taste that can be described as garlicky/oniony. Make sure to fry the asafoetida in a bit of oil/butter before you use it, or (if you’re using other spices and herbs) fry them first and then add the asafoetida last. This brings out the flavor even better. Start with a small amount, and work your way up to a taste you like, because it’s quite strong!

Onion-infused oil is a great alternative if you really want to nail the onion flavor. You can either buy it in the better supermarkets or make it yourself. If you make it yourself, be careful not to store it. Because of the moisture in the onion, there is a chance that Botulism occurs (read more here). To be safe, just heat up some oil in the frying pan, cut your onion in big chunks, fry the onion chunks in the oil till they’re golden and remove the onion from the oil. You can use this oil, without having to worry about FODMAPs.

Ramson. Lesser known, but still very tasty is ramson. It is not included in the Monash FODMAP app, but the FODMAP content can be found in this study. Use the ramson in cold dishes (like salad, sauces, or pesto), because it loses its flavor when it’s heated.

What is your favorite onion substitute? Let me know in a comment below!

Similar Posts


  1. Thank You! I’m latin and Onion and garlic is a staple (along with beans…LOL) so you understand my jaw drop when my Gastro specialist said Low FODMAP for me. I will try the green tops of the spring onions, I will try to sauté them in oil (olive oil).

    1. Hi Elizabeth,
      I can totally understand your struggles! Let’s hope beans and garlic/onions are not among the FODMAPs you’re actually intolerant to, so you can hopefully eat them again soon! Good luck.

  2. Someone on the net suggested boiling onions so that the fructans in the onions will leach out into the water and then throw the water out before using the cooked onions in a recipe like stir fries, etc. I wonder if the cooked onions will still have some remaining vitamins, etc.

    1. Hi Cindy, that is an interesting approach. But not something I’d be comfortable trying or recommending. There are no studies or tests that have tested leftover fructans in onions after boiling them, and soaked products (like chickpeas) don’t lose all of their FODMAP content, it just lowers it. As for vitamins, you probably lose a lot of those too, I’d imagine.

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.