Onion and garlic are among the first foods people learn to avoid on a low FODMAP diet. This is likely because they are very common in many cuisines, but can cause stomach issues even in small amounts. Research on FODMAP content in foods is constantly being updated, and it can be challenging to stay up-to-date. Here, we have gathered an overview of the latest research on different types of onion and garlic, as well as good alternatives and tips.

Different types of onion and garlic have been analysed in laboratories for FODMAP content:

Brown onion – Low FODMAP at 26g (according to FODMAP Friendly)

Pickled small onions (German type) – Low FODMAP at 3g

Pickled large onion – Low FODMAP at 60g

The general recommendation from Monash is to avoid onions during

 and instead test individual tolerance during 

 This is because many people react to onions even in small amounts, and it is easy to exceed the allowed limits.

If you are careful and cook your own meals, small amounts of onions can be included within the recommended limits. Some types of pickled onions and garlic in vinegar have also been tested, and the results show that pickling can reduce the FODMAP content when the brine is drained. This is because FODMAPs leach into the liquid, which reduces the FODMAP content in the onions themselves.

What about products containing small amounts of onion and garlic?

Several store-bought products with small amounts of onion or garlic have been found to be low FODMAP in limited quantities. Examples include sriracha, satay sauce, and mango chutney. These products may be safe in the amounts tested by Monash, even during the 

 However, it is important to be mindful of portion sizes and remember that products found in British stores can vary from those tested.

When it comes to garlic and onions tested in the laboratory, this refers to 

 have not been analysed. Especially onions contain a lot of water, which means that the FODMAP content in onion powder is likely to be very concentrated and high even in small amounts. Therefore, it is difficult to say anything definitive about safe amounts in products containing onion powder or garlic powder unless they have been specifically tested in the laboratory.

Also, the FODMAPs in onions and garlic are water-soluble, meaning they leak out into the food when used in cooking, such as in stews or soups – even if they are removed before serving.

Onions and garlic do not need to be completely avoided on a low FODMAP diet, but Monash generally recommends excluding them during 

, as they often trigger stomach issues even in small amounts. Small amounts of onions and garlic in tested store-bought products may be safe, but if you are unsure, it may be best to avoid them during the strict phase of the diet and instead test your own tolerance afterwards.

Fortunately, many people find that they can tolerate small amounts of onions and garlic during 

 allowing them to include these foods in their diet in the long term. If you do not tolerate them well in the first reintroduction round, it is recommended to test your tolerance again later, as it can change over time.

Fortunately, there are good alternatives that provide much of the same flavour:

Spring onions (green part has fewer FODMAPs than the white part)

Leeks (green part has fewer FODMAPs than the white part)

Garlic-infused oil – Can be bought ready-made or made at home by infusing fresh garlic in oil and then removing it. However, be aware that there is a small risk of botulism if homemade garlic oil is stored over time. The safest option is therefore to buy ready-made garlic oil or to sauté the garlic in the oil just before using it in cooking.

Low FODMAP onion and garlic replacement from FreeFOD

Since FODMAPs in onions and garlic are water-soluble, they do not leak into oils (which are fat-based). Therefore, garlic-infused oil is a safe alternative, as long as it does not contain garlic pieces or extracts.

By using these alternatives, you can still enjoy plenty of flavour in your meals without risking problems!

When evaluating products in the app, we prioritize specific products that have been tested in a laboratory first, followed by the ingredient list of each individual product. This means that if a product, such as sriracha, has been tested by Monash, we base our assessment of similar sriracha products on those test results. It's important to be aware that store-bought products may differ from the tested versions. However, we consider this the most reliable assessment, as it is based on laboratory analysis.

Everything you need to know about onion and garlic on the low FODMAP diet – what has been tested, safe amounts, and great alternatives 🧅



Noba

Garlic and Onion on the Low FODMAP Diet