Are Soy Products Low FODMAP? A Breakdown by Type
So, are soy products low FODMAP? Some are—and some definitely aren’t. It all comes down to processing, form, and serving size. Let’s unpack it.
Soybeans: The Starting Point
At the source of all soy products is the humble soybean. Unfortunately, whole soybeans are high in FODMAPs, primarily due to their GOS (galacto-oligosaccharides) content. That means edamame and soybeans used in salads or soups should generally be avoided during the elimination phase of the diet.
Low FODMAP status? ❌ No
Reason: High in GOS
Safe serving size: None during elimination phase
Tofu: Yes and No
Tofu is made from soybeans, but its FODMAP content depends on how it's prepared.
- Firm or extra-firm tofu: Good news—firm tofu is low FODMAP in 170g servings (about ⅔ cup). That’s because it’s pressed and drained, removing much of the water-soluble GOS during processing.
- Silken tofu: On the other hand, silken tofu is high FODMAP, as it retains much of the GOS from the soybeans.
So when it comes to tofu, texture matters—the firmer, the better.
Firm tofu = ✅ Yes
Silken tofu = ❌ No
Soy Milk: Choose Carefully
Soy milk is another tricky one, because its FODMAP status depends on how it’s made:
- Soy milk made from whole soybeans: High FODMAP due to retained GOS
- Soy milk made from soy protein isolate: Low FODMAP in 1 cup (250ml) servings
In many countries (like the U.S.), soy milk is usually made from whole soybeans. But in some regions, especially Australia and the UK, soy protein-based soy milk is common—and safe.
Check the ingredients list. If it says “soy protein” or “soy protein isolate” as the base, you’re likely in the clear.
Tempeh: A Gut-Friendly Option
Tempeh is a fermented soy product that’s higher in protein and fiber than tofu. The fermentation process breaks down many of the FODMAPs, making tempeh low FODMAP in moderate portions (up to 100g).
It also offers gut health benefits thanks to naturally occurring probiotics (though cooking may reduce them).
Tempeh = ✅ Yes, up to 100g
Soy Sauce: Surprisingly Safe
Here’s a pleasant surprise: soy sauce is low FODMAP in a standard 2 tablespoon (42g) serving. Even though it’s made from soy, the FODMAPs are broken down during fermentation and processing.
Just avoid “sweet soy sauces” or versions with added garlic, onion, or high fructose ingredients.
Soy sauce = ✅ Yes
Tamari (gluten-free soy sauce) = ✅ Also low FODMAP
Final Thoughts: Can You Eat Soy Products on a Low FODMAP Diet?
Yes—but you need to be selective. Soy can either be totally fine or a major trigger, depending on how it’s processed. Here's your quick guide:
✅ Low FODMAP Soy Options:
- Firm or extra-firm tofu
- Tempeh (up to 100g)
- Soy milk (only if made from soy protein)
- Soy sauce and tamari
❌ High FODMAP Soy Products to Avoid:
- Whole soybeans or edamame
- Silken tofu
- Soy milk made from whole soybeans
- Products with added soy flour or soybeans
Always check labels, mind your serving sizes, and if you’re ever unsure—start small and track how your body responds.
