What is the deal with Soy and the Low FODMAP diet?

Soy and FODMAPs have been a bit confusing in the past with many people assuming that soy is high FODMAP, which is fair enough as soy beans are high in FODMAPS (specifically GOS and FRUCTAN).

The good news is that there are many soy porducts that are actually low in FODMAPs such as some soy milks (made from soy protein), and some soy products made from fermented soy such as soy sauce, miso and tempeh. Firm tofu is also low FODMAOP due to the porcessing of the tofu.

Read on to find all the FODMAP and soy facts and how you can safely include soy in your diet if you are sensitive to GOS and /or Fructans.

Soybeans

Soybeans are high in the FODMAP galacto-oligosaccharides or GOS for short. This is not surprising as GOS is generally found in legumes. The Monash Low FODMAP app does not state a low FODMAP level of soy beans.

So soybeans and foods that contain soybean as an ingredient are not considered low FODMAP- although there is an exception- see soy sauce below.

Edamame

Edamame are soybeans which have been harvested early so juvenile soy beans. Monash Low FODMAP app states that frozen edamame are low FODMAP at a normal serving size (1/2 cup) but turn into moderate FODMAPs (FRUCTANS) at 1 1/2 cups. So include edumame beans but watch the upper limit in a sitting.

Soy Milk

In Australia, you can find soymilk products made from either soy beans or soy protein. For soy products to be considered low in FODMAPs it needs to come from the soy protein extract whereby the carbohydrate component (GOS) is removed in the processing.

Unfortunately, most soy milks are made from soybeans, which are high in FODMAPS (specifically GOS). Soy milk products in Australia that are low FOMDAP currently available include So Good and Inner Health soy milk (Aldi), and some other home brands. However, in other countries, may be more difficult to source soy milk made from soy protein. Soy milks used in cafes will usually be high FODMAP like most soy milks.

Soy Yoghurt

Most soy yoghurt is made from soybeans so avoid or have as a low FODMAP dose in a sitting (2 tablespoons).

Theoretically soy yoghurt can be made from soy protein but tend to also have a high FODMAP ingredient such as inulin added.

If you make your own yoghurt from a low FODMAP soy milk- that would be fine.

Coconut yoghurt is low FODMAP for an alternative- but again check no FODMAPs ingredients such as inulin is added.

Soy Cheese

Soy cheese is low in FODMAPs for a normal serve (a normal serve being 40g or 2 slices)

Tofu

Tofu is also made from soybeans and in processing soy beans to make a firm tofu, a lot of water is drianed. As FODMAPs are soluble in water, this porcess also drains the FODMAPs away.

Silken tofu is high as it has not been pressed and drained like firm tofu which means it retains the FODMAPs of the soybeanand is a high FODMAP food.

Miso

Miso paste is low FODMAP as is made from fermented soy beans. A normal serve is one tablespoon in a sititng. It takes a lot of miso paste before it is considered moderate in FODMAPs (abvout 6 tablespoons) so can be eaten without worrying about an upper limit.

Tempeh

Tempeh is also a great option (especially if you are vegan), it is high in protein, and although it is made whole soybeans, this product is mildly fermented which reduces the FODMAP content enough to make it low FODMAP.

Soy Sauce

Soy sauce is Low FODMAP for a normal serve, even if soybean is listed on the ingredient list. The processing and fermentation reduces the FODMAP content and renders it low FODMAP.

Soy Flour

High in FODMAPs and a real pain as often in foods that could have otherwise been low FODMAP.

Soy flour is likley fine as a minor ingredients ingredient, although Monash FODMAP has not tested small amounts of soy flour. Gluten free bread (1 -2 slices) with soy flour as a minor ingredient will will likely be low FODMAP due to the low dose of soy flour but avoid a product that has soy flour as a major ingredient for example San Rempo Gluten Free pasta which will conatin a lot of soy flour- and often will cause issues for people who are FODMAP sensitiuv.

Soybean oil

Oils are made from fat and not carbohydrates so all oils, including soy oil, are low in FODMAPs.

The only exceptions are when high FODMAP ingredients may have been added such as garlic pieces, although garlic infused oil is quite acceptable and forms an important part of the low FODMAP diet.

Soy Lecithin

Soy lecithin is added to foods to help with producing a better quality food product but has negligible carbohydrate so not a FODMAP issue.

TVP (Textured Vegetable Protein)

High in FODMAPs as made from soy legumes.

Soy has a number of possible health benefits. Knowing how to choose low FODMAP forms of soy means you can continue to enjoy the health benefits of soy while following a Low FODMAP diet.

Updated 20/2/25

References

1. Monash University FODMAP Diet app. Version 3.1.3. Accessed 20/2/25.

2. FODMAP Friendly app

3. The Nutrition Source. (2019). Straight Talk About Soy. [online] Available at: https://www.hsph.harvard.edu/nutritionsource/soy/ [Accessed 18 Jun. 2019].