Fillers and stabilizers
Konjac (glucomannan)
Definition
What it is
Konjac / glucomannan: highly concentrated dietary fiber from the konjac plant; a high-FODMAP ingredient that can cause significant gas and bloating in sensitive individuals at the doses used in food products.
On the label
How it appears on labels
- konjac
- glucomannan
- konjac flour
- konjac gum
- konjac starch
- e425
Regulation
Regulatory status
No bans or restrictions are recorded for this ingredient in the jurisdictions clearlabel tracks (US, EU, UK, Canada, Japan, Australia/NZ, Brazil).
Explainer
In plain language
Konjac is a fiber made from the root of the konjac plant, and its main component is a soluble fiber called glucomannan. It absorbs a large amount of water and forms a thick gel, which is why it is used to thicken foods, make low-calorie noodles and jellies, and add fiber. It has almost no calories and little flavor, doing its job through texture and bulk.
Assessment
Why it is flagged
The flag is mostly about digestive tolerance and, separately, a physical choking and swelling concern in certain products. As a highly water-absorbing fiber, konjac can be fermented in the gut and is considered high-FODMAP, so it can cause gas and bloating in sensitive people at the doses used in foods and supplements. Studies of glucomannan have examined both its fiber effects and its tendency to swell. Regulators have acted on the physical hazard specifically: konjac has been restricted or banned in certain mini-cup jelly candy formats in the US and EU because the firm gel can pose a choking risk, particularly for children. It remains permitted as a food additive (E425) in many products. Clear Label flags it as low severity so both the digestive pattern and the product-specific cautions are visible, and the gut response is something you can test in your own logs.
In the aisle
Where it commonly shows up
- Shirataki and konjac noodles
- Konjac jelly snacks and fruit jellies
- Low-calorie and keto pasta alternatives
- Fiber and weight-management supplements
- Some vegan gummy candies
- Thickened sauces and desserts
Practical
Reading the label
It appears as konjac, glucomannan, konjac flour, konjac gum, or the additive code E425. It is common in products marketed as low-calorie, low-carb, or high-fiber, and glucomannan is the name to look for on supplement labels.
Alternatives
If you want to avoid it
Some people who bloat with konjac choose noodle or thickener alternatives such as shirataki-free options, whole-grain pastas, or dishes thickened with small amounts of starch. For fiber, whole foods like vegetables and legumes are gentler for some digestions.
FAQ
Common questions
Why is konjac restricted in some candies?
In certain small cup-shaped jelly candies, the firm konjac gel does not dissolve easily and has been linked to choking incidents, especially in children. Because of this physical risk, regulators in the US and EU restricted or banned konjac in some of those specific products.
Does konjac cause bloating?
It can. Konjac is a highly water-absorbing, high-FODMAP fiber, so it may be fermented in the gut and cause gas or bloating in sensitive people at food-level doses.
What is the difference between konjac and glucomannan?
Glucomannan is the main fiber found in the konjac root, so the terms are closely related. On labels you may see either name, and supplements usually list glucomannan.
Citations
Sources
Citation
Primary reference
About this page: the definition, label names, severity, and regulatory chips come from the clearlabel ingredient taxonomy, the same data the scanner uses to score products. Research summaries describe associations reported in published studies, not diagnoses; individual responses vary. Scan any product with clearlabel to see which of its ingredients carry flags.