Comparison table. Erythritol: no effect on blood sugar, very well tolerated, calorie-free. Xylitol, also called birch sugar: small effect on blood sugar, good for the teeth, can have a laxative effect from about 20 to 30 grams. Maltitol: raises blood sugar noticeably, caution. Traffic-light rating from green for favourable to red for caution.
Sugar alcohols at a quick glance
Substance
Blood sugar
Special note
Traffic light
Erythritol
no effect
calorie-free, very well
tolerated
Xylitol
= birch sugar
small (GI ~7–13)
good for the teeth;
laxative from ~20–30 g
Maltitol
(Maltitolit)
noticeable (GI 35)
raises blood sugar
the most – caution
🐕 Important for dog owners
Xylitol (birch sugar) is toxic to dogs – even small amounts can be dangerous.
Erythritol: the blood-sugar-neutral favourite
Evidence level: established
Erythritol practically doesn’t raise blood sugar (glycaemic index around 0) and is calorie-free. It’s largely excreted unchanged and is therefore usually well tolerated – though in larger amounts it affects digestion slightly in some people. For the blood-sugar-conscious it’s thus the most straightforward candidate.
Xylitol (birch sugar): tooth-friendly, with a small blood-sugar effect
Evidence level: established
Xylitol – often sold as birch sugar (it’s the same substance) – raises blood sugar only a little (GI ~7–13, largely insulin-independent). Its plus point: it’s considered good for the teeth, because caries bacteria can’t metabolise it into acid. The downside: from about 20–30 g per day it can be laxative and cause bloating.
Xylitol (birch sugar) is toxic to dogs – even small amounts can be dangerous. Keep it well out of reach.
Maltitol: the problem case among sugar alcohols
Evidence level: established
Maltitol is the exception: it raises blood sugar noticeably (GI 35 – about half as high as table sugar) and can also be laxative. It’s often found in “sugar-free” chocolate. Anyone watching their blood sugar should read the ingredients list especially carefully for maltitol. Why that is, and how “sugar-free” can mislead, is covered in detail in the article on “sugar-free” sweets.
Key takeaways
- Erythritol: doesn’t raise blood sugar, calorie-free, usually well tolerated.
- Xylitol (birch sugar): small blood-sugar effect, good for the teeth, laxative from ~20–30 g – and toxic to dogs.
- Maltitol: raises blood sugar noticeably (GI 35) – the problem case.
- Read the ingredients list: the name of the sweetener decides the blood-sugar effect.
Sources
Sources as of: 21 Jul 2026.
- Erythritol and xylitol: blood-sugar effect, tolerance, calories. Nutrient reference. naehrstoffallianz.dsgip.de
- Xylitol (birch sugar): dental benefit, laxative threshold, toxicity to dogs. Reference. gesundfit.de
- Xylitol – benefit and risks (incl. dogs). IKK classic. ikk-classic.de
- Glycaemic index of polyols incl. maltitol (GI 35). Livesey (2003), PubMed. pubmed.ncbi.nlm.nih.gov