By Caroline Tuck, Dietitian, PhD Candidate
Confused about whether or not you can use onion and garlic in your cooking on a low FODMAP diet? Have you heard about adding big pieces of onion and garlic into cooking and removing it before consuming the meal, but you're not sure if this actually works? This post should help clarify a few of your queries.
Onion and garlic both contain fructans (oligosaccharides) and therefore during a restrictive phase of the low FODMAP diet, they should be excluded from the diet. However, there are a few tricks of the trade to get keep their flavor in your cooking.
The fructan content in onion and garlic are soluble in water. This means that if you put onion or garlic into a soup or stock, some of the fructan content will leech out into the water. Therefore the strategy of putting a whole onion or garlic clove into a soup and then pulling the pieces out before consuming the soup will not work, as the fructan content will have already leeched into the water.
In an oil based dish the fructans will not leech out (as fructans are not soluble in oil). Therefore, if you are making something based in oil, for example a stir-fry, it is possible to add a large piece of onion or a whole garlic clove and simply pull the pieces out before adding other ingredients. This way you will have the flavour without the fructan content leeching into the meal.
The other alternative that works very well to get some flavour into your cooking is using the green parts of spring onion or chives as a replacement for onion. When using these alternatives, keep in mind that they won’t need to be sautéed for as long as regular onion and you may prefer to add them into the pot later in the cooking process to get maximum flavour from them. For some garlic flavour you can make your own garlic infused olive oil which you can use in your cooking instead of your regular oil. The Indian spice Asafoetida powder can also be used as a spice to replace onion flavour and you can buy this from an Indian supermarket (be careful when using it as it has a potent smell). Other low FODMAP flavours include ginger, fresh herbs, spices, lemon and lime juice.
Remember that everyone’s tolerance to foods is different, so it is always best to test out some of these strategies yourself and see if you feel that you are able to tolerate them.