Dinner
Ginger Rice-Noodle Stir-Fry
20 minMedium
Tofu (firm/extra firm)
Legumes & Tofu · Tofu Tempeh
TLDRLast updated 3 September 2026
Soybeans are one of the richest sources of GOS on the shelf, and yet firm tofu is rated green at two-thirds of a block (170 g), holding just 0.08 g of it. The difference is the pressing. GOS dissolves in water, so when the curd is pressed and the whey runs off, most of the GOS runs off with it.
Last updated 3 September 2026Serving sizes for tofu (firm/extra firm)
The tested serve is two-thirds of a block (170 g), rated green. GOS is the only group present.
0.7 blocksabout 170 g
Tested serving sizes
| Serving | Amount | Main FODMAP | Rating |
|---|---|---|---|
| 2/3 block | 170 g | GOS 0.08 g |
Breakdown for 0.7 blocks
0gFructose
0gLactose
0gFructans
0.08gGOS
0gSorbitol
0gMannitol
0.7 blocksabout 170 g
Is tofu (firm/extra firm) low FODMAP?
At the tested serve the only FODMAP detected is GOS, at 0.08 g, under the 0.1 g moderate line, with fructose, lactose, fructans, sorbitol and mannitol all sitting at zero. That is a striking result for something made from a legume, and it comes from the manufacturing rather than the bean. Soy milk is coagulated, the curds are lifted away from the whey and then pressed under weight, and the water-soluble GOS goes out with the liquid. The same principle runs along the whole soy shelf: soy milk made from soy protein is green, while soy milk made from whole beans is amber.
Tofu (firm/extra firm) and IBS: what to know
Two-thirds of a block is a full portion of protein and it still comes back green, which matters a great deal if you are cutting back on beans and lentils, most of which are green only in small, drained serves. Texture is the thing to watch on the tofu shelf. Silken tofu is listed separately with its own tested serve, because it sets in its container and is never pressed, so it keeps the whey that firm tofu loses. When a tofu meal causes symptoms, the marinade is the first suspect, not the tofu.
Gut-friendly ways to eat tofu (firm/extra firm)
Buy the firmest block you can find and press it again yourself under a weight for half an hour. Less water means better browning, and since GOS dissolves in water, whatever leaves is not something you will miss. Marinades are where tofu usually goes wrong, because bottled teriyaki, hoisin, black bean and satay sauces are nearly all built on garlic and onion. Mix your own from tamari, ginger, sesame oil, rice vinegar and maple syrup, crisp the cubes first, then add the sauce at the end.
Recipes with tofu (firm/extra firm)
Frequently asked questions
How much firm tofu can I eat in a meal?
Two-thirds of a block is the amount that has been tested, and it rates green, which is already a generous main-meal serve of protein rather than a garnish. That is the one point the data gives you, so treat it as the portion you can count on. In practice most people are eating less than that in a stir-fry or a curry anyway.
Is silken tofu low FODMAP too?
It has its own entry and its own rating in the guide, and it is worth checking rather than assuming. Silken tofu is set directly in its packaging without being drained or pressed, so it never loses the whey that carries GOS away in firm tofu. Treat the two as different foods with different serving sizes, not as one ingredient in two textures.
Is tempeh low FODMAP?
Tempeh is rated green in the guide, and it gets there by a different route from tofu. Rather than pressing the GOS out, tempeh is made by fermenting whole soybeans, and the culture works through some of the fermentable sugars before you ever eat it. Between the two, you have a firm plant protein for most cooking and a chewier one for grilling.
Why does my tofu stir-fry upset me if tofu is low FODMAP?
Look at everything else in the wok. Onion and garlic go in first in most recipes, the sauce is usually a bottled one built on both, and a stir-fry is an easy place to pile in a cup of broccoli or a handful of snow peas well past their own serves. The tofu is carrying 0.08 g of GOS and very little blame.
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