Are Red Onions Low FODMAP?

Red onions are a little milder in flavour than their more commonly used cousin the white onion. Both are tasty and add delicious flavour to lots of meals and recipes. But most allium vegetables are high in FODMAPa. So, are red onions low or high FODMAP?

Unfortunately, red onions are considered high in FODMAPs and should be avoided while following a low FODMAP diet. You could try using certain parts of a leek or spring onion instead but you do need to take care because these can also be high in FODMAPs too.

Eating Red Onions on a FODMAP Diet

The FODMAP in question when it comes to red onions is oligosaccharide. This is a fructan that helps give the veggie that delicious flavour but it is also the culprit when it comes to digestive issues or IBS flare-ups.

It might be tempting to try and find ways around this like adding onion to your meal then removing them but it is best not to. Even if you have cooked and removed the onion from the meal, many of the FODMAPs will have leached out into the food already and you may still have a problem.

The best thing to do is avoid onion and find other alternatives to add flavour to your meals instead.

Avoid Red Onions as they are High FODMAP at All Quantities

Low FODMAP Alternatives To Red Onions

Whilst it may seem difficult to find out that you can no longer use onion in your cooking you don’t need to lose all hope. There are alternative options you can use instead.

These won’t be quite the same as a red or white onion but you will still end up with a tasty meal:

Leeks and Spring Onions

Both leeks and spring onions are from the same onion family as red onion and they do contain FODMAPs when you use the white bulb as normal. However, if you throw the white section of both of these vegetables away and use the dark leafy green section instead then you can pop them into your meals.

This will give you a little of the same oniony flavour but without the FODMAPs. Be careful not to use too much though because they do still contain some FODMAPs and too much will send your meal back into the dangerous high FODMAP zone again.

Asafoetida Powder

This powder can be used to add the flavour but without adding the onion vegetable. Asafoetida powder is an Indian spice that has been tested by Monash University and is low FODMAP.

All you need is to pop a pinch or two into your cooking and you will still get that delicious flavour but without the FODMAP problems.

Other Onion-Related Products

As you well know, onions come in many forms. But are these other forms any better for someone following a low FODMAP diet?

Are White Onions Low FODMAP?

If you are looking to use white onions instead of red onions in your cooking then you are out of luck.

Unfortunately, these are high in FODMAPs too and suffer very similar problems to red onions and any other type of onion. Instead of white onion, you could try using the leafy green section of a leek (Just make sure you throw away the white bulb section) or the Indian spice, Asafoetida powder.

Are Spring Onions Low FODMAP?

Spring onions as you would normally use them are not low FODMAP. The white onion bulb is high in FODMAPs and should be avoided. However, if you want a touch of that oniony flavour you can use the leafy green section.

This is the part you would normally throw away but it is edible and if you sautee it then it can be delicious too. 

Are Leeks Low FODMAP?

Leeks are another vegetable from the onion family that when used traditionally is high FODMAP. The white bulb should not be used because it contains high amounts of FODMAPs.

You can choose to use the green leafy section instead. This might be enough to add some onion flavour to your meal without the FODMAPs. Just make sure you are chopping off the green end and using that.

When the leek starts to fade to pale green and white is the section you need to throw away.

Quick Summary

It is difficult to learn that a flavour such as onion that is commonly used in almost all of our favourite recipes is high FODMAP and needs to be avoided. However, there are some alternatives you can try and you may find you like an onion-free diet after all!