Soy foods can be a nutritious part of the diet, offering protein, fiber, and valuable micronutrients, especially for those following a vegetarian or vegan lifestyle. But if you’re navigating the low FODMAP diet for IBS, soy often becomes one of the most confusing foods to figure out.
As a registered dietitian who specializes in helping people manage IBS with the low FODMAP approach, I understand just how overwhelming these details can feel. In this guide, I’ll break down the factors that influence the FODMAP content of different soy products, clarify which options are safe to enjoy, and highlight those you may want to limit during the elimination phase.
Let’s dive in!
Is Soy Low FODMAP?
Soybeans naturally contain FODMAPs – mostly galacto-oligosaccharides (GOS) and fructans. But that doesn’t mean every soy-based food is automatically high in FODMAPs. In fact, whether a soy product works for a low FODMAP diet depends on a few key factors: how it’s processed, whether it’s fermented, and even the maturity of the soybeans used. Let’s walk through each of these factors so you can better understand which soy foods may be suitable for you.
Processing Methods Affect the FODMAPs in Soy
GOS and fructans are soluble in water, and this property has important implications for how soy products fit into a low FODMAP diet. When soybeans are processed in a way that retains the water, the final product will also retain the FODMAPs, resulting in a high FODMAP food. Conversely, when the processing method involves soaking the beans and then straining away the liquid, much of the FODMAP content is removed, producing a low FODMAP product.
For example, soy milk made from whole soybeans is high in FODMAPs because the water used in processing is not removed; the same applies to soy yogurt, which is made from soy milk. In contrast, soy milk made from isolated soy protein – commonly available in Australia but less so in the U.S. – is low FODMAP.
Similarly, firm tofu is considered low FODMAP because the manufacturing process involves pressing and draining the liquid, thereby removing a significant portion of the water-soluble FODMAPs. If you’ve never tried it, my Colorful Asian Tofu Stirfry is an easy and delicious recipe to experiment with.
Silken tofu, on the other hand, retains water during preparation and therefore contains higher levels of FODMAPs.
Fermentation Can Lower the FODMAPs in Soy
Tempeh is made from the fermentation of cooked soybeans, which reduces their FODMAP content to a low FODMAP threshold. Some tempeh varieties also have grains like rice or millet, which are low FODMAP grains. Others, however, may include barley, a high-FODMAP grain, which should be avoided.
Miso and soy sauce (or tamari, the gluten-free version of soy sauce) are two other low-FODMAP, fermented soy products.
The Maturity Level of Soy Matters
Mature soy beans (either dried or fresh) are high in FODMAPs. As soy nuts are usually made from mature soy beans, we can assume they are high FODMAP as well (although they have not yet been formally tested).
On the other hand, edamame, also known as immature soybeans, is low FODMAP in moderate amounts.
Soy Food Derivatives
What about processed foods and other ingredients made from soy? More and more soy products are appearing on our supermarket shelves, and it can be hard to tell whether they are suitable for a low FODMAP diet. Let’s take a look at them.
Soy burgers or meat substitutes have not been tested, but most are likely to be high in FODMAPs as they may contain fibers from soybeans.
Textured soy protein (TVP), the main ingredient in many soy-based meat substitutes, is high in FODMAPs.
Soy protein powder may be low in FODMAPs depending on the processing. Until we have more testing, its FODMAP status is unknown.
Sweet Soy Sauce/Ketjap/Kecap Manis is low FODMAP in small amounts.
Douchi (fermented black soybean) is low FODMAP in small amounts.
Soy flour is high in FODMAPs.
Soy cheese (cheddar style) is low in FODMAPs. We don’t have any information about other types of soy cheese yet.
Soybean oil does not contain FODMAPs. FODMAPs are carbohydrates and are not found in any oils.
Soy lecithin, an emulsifier used in small quantities in several processed products, is a combination of an oil and a fat, and does not contain FODMAPs.
In addition, some of these products may also contain other high-FODMAP ingredients, such as garlic or onions.
Low and High FODMAP Soy Foods Guide
You can include many soy products in a low FODMAP diet. Use this guide to navigate the soy aisle, and don’t be afraid to experiment with soy foods. For specific and up-to-date portion sizes, consult the Monash FOMDAP App.
Low FODMAP Soy Foods
- Tofu (firm or extra firm)
- Plain Tempeh (no barley or other high FODMAP ingredients)
- Edamame (fresh or frozen)
- Soy sauce (or shoyu)
- Tamari (wheat-free soy sauce)
- Miso
- Soy cheese (cheddar style)
- Soybean oil
High FODMAP Soy Foods
- Mature soybeans
- Soy milk (made from soybeans)
- Soy yogurt
- Silken tofu
- Soy burgers/meat substitutes
- Textured soy protein
- Soy flour
Wrapping It All Up: Making Soy Work for Your Low FODMAP Lifestyle
Navigating soy foods on a low FODMAP diet may feel daunting, but it doesn’t have to be that way. With a clear understanding of processing methods, fermentation, and the maturity level of the soybeans, you can confidently choose soy products that nourish without triggering IBS symptoms.
Soy is a nutritious and versatile food that can belong in your low FODMAP diet. It just requires smart choices. I encourage you to experiment with the low-FODMAP soy options I’ve discussed, and observe how your body responds.
Remember: the low FODMAP diet is only temporary. When you are ready to move to the next step and reintroduce FODMAPs, including GOS and fructans, you can find out whether you can bring back the high-FODMAP soy products as well (and many other foods). Many of my clients are surprised to learn that they can tolerate many different foods they thought were off limits.
Working with an expert dietitian (like me) can help you figure out which foods are triggering your gut symptoms. If you find that certain foods don’t sit well with you, I can help you explore enzyme options that may make it easier to enjoy them again without the uncomfortable side effects.
If you want to learn more about how I can help you find relief from bloating, abdominal pain, and unpredictable bowel movements, reintroduce more foods into your diet, and feel good at the same time, book your complimentary IBS Clarity Session.
We will review your symptoms and history and discuss the best next steps for you! You will come out of this call feeling relieved and hopeful that you can take control of your IBS.
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Book a free IBS Clarity Call today!
Published October 9, 2019. Updated, September 8, 2025.
Antonella Dewell, MS, RDN | IBS Resolution Expert
Antonella Dewell is a registered dietitian and IBS specialist based in California. She has over 2 decades of experience working in clinical research at Stanford. Since 2018, she has been running a private practice. She helps people with IBS gain real, lasting relief from IBS symptoms in just 2-4 weeks without giving up all the foods they love, so they can stop feeling anxious around food and get back to fully enjoying food and life again.
