Tofu (silken/soft)
Legumes & Tofu · Tofu Tempeh
Weigh out 170 g of silken tofu and you have 0.3 g of GOS and an amber rating. The same 170 g of firm tofu is rated green on 0.08 g. Same bean, different set, different answer. Silken tofu is green at a third of a block, 85 g, and that third is the portion to work to.
Last updated 4 September 2026Serving sizes for tofu (silken/soft)
A third of a block, 85 g, is rated green. Two thirds, 170 g, is rated amber.
Tested serving sizes
| Serving | Amount | Main FODMAP | Rating |
|---|---|---|---|
| 1/3 block | 85 g | GOS 0.15 g | |
| 2/3 block | 170 g | GOS 0.3 g |
Breakdown for 0.33 blocks
Is tofu (silken/soft) low FODMAP?
GOS is the only group in play, at 0.15 g in a third of a block and 0.3 g in two thirds, which is where the rating turns amber. The reason lies in how the block is made. Silken tofu is set in the tub it is sold in, a soft custard of soy milk left whole, so it is never cut, drained or weighted, and whatever GOS the soy milk carried is still there when you peel the lid off. Firm tofu sets out what changes when that liquid is squeezed out instead.
Tofu (silken/soft) and IBS: what to know
Silken tofu is rarely eaten in slices, and that is where portions go astray. It is the tofu of smoothies, chocolate mousse, blended dressings and creamy pasta sauces, all of which start with a whole block and divide it by however many people are at the table. Two servings of a mousse made from one block is well past the green third. Miso soup is the gentler habit, since the cubes floating in a bowl add up to a small fraction of a block.
Gut-friendly ways to eat tofu (silken/soft)
Portion before you blend, not afterwards. Cut the block into thirds while it is cold and firm from the fridge, then build the smoothie, the dressing or the dessert on one of them and wrap the rest. Silken tofu also stands in for cream in a soup or a curry sauce, where a third of a block will thicken a pot for several people without anyone noticing. When protein is the point rather than texture, move to firm tofu or tempeh, both cleared at serves built for a main meal.
Frequently asked questions
How much silken tofu can I eat on a low FODMAP diet?
A third of a block is the green serve and two thirds is amber, so the block itself is your measuring device. Cut it in three and one piece is a smoothie, a dessert or a sauce for the pot. Amber does not mean off limits, but it is a portion to test on purpose rather than one to reach for on a bad week.
Is silken tofu the same as soft tofu?
Close enough that they share an entry here. Both are coagulated straight in their packaging and sold sitting in liquid, and neither goes under a weight, which is what keeps the GOS in the block. The dividing line that matters for portions is between these and the firm or extra firm blocks, which are pressed and rated separately.
Can I use silken tofu in a smoothie with IBS?
Yes, if you measure the tofu before it goes in the blender. A third of a block gives a smoothie its body and protein and stays inside the green serve, whereas half a tub tipped in by eye lands you nearer the amber one. The fruit deserves as much attention: a whole banana or a mango can outweigh the tofu for FODMAPs in the same glass.
Why is silken tofu not as low FODMAP as firm tofu?
It keeps its water. GOS is water-soluble, so a block that never has liquid pressed from it holds on to what the soy milk brought, which is why two thirds of a silken block rates amber while firm tofu is rated green at the same weight. Texture, in other words, is a reasonable guide: the wetter and wobblier the tofu, the more it is carrying.
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