Last reviewed: July 2026

Sugar alcohols: why "sugar-free" isn't calorie-free

Sugar alcohols, or polyols, are sweeteners that carry roughly half the calories of sugar: EU labels count them at 2.4 kcal per gram against sugar's 4. They let a product print "sugar-free" while still delivering real calories and, for some polyols, a real blood sugar response. A striking example from the Dietly database: sugar-free chewing gum lists 0 g sugar next to 68 g of carbohydrate and 167 kcal per 100 g. The gap between those numbers is the polyols. Gum portions are tiny so it hardly matters there, but the same accounting sits inside sugar-free chocolate, protein bars and keto sweets in portions that do.

What polyols are and where they hide

Chemically, polyols are carbohydrates whose structure resembles both a sugar and an alcohol (no relation to drinking alcohol). The common ones on ingredient lists are maltitol, sorbitol, xylitol, isomalt, lactitol and erythritol, plus the catch-all "polyols" on EU labels. They sweeten at 40 to 100 percent of sugar's intensity and, unlike intense sweeteners, they also provide bulk and texture, which is why sugar-free chocolate and baked goods lean on them: aspartame cannot replace the physical mass of sugar in a bar, but maltitol can.

You will find them wherever "sugar-free" or "no added sugar" meets a solid food: chewing gum, mints, diabetic chocolate, some protein bars (this one shows 34.5 g carbohydrate but only 0.6 g sugar per 100 g, a signature polyol gap), and keto products such as keto granola. Diet drinks are the exception: liquids do not need bulk, so they use intense sweeteners instead, covered in is diet soda worse than regular.

Reading the label: the carb-sugar gap

The fastest tell is comparing the carbohydrate line with the sugars line. In a normal sweet product they travel together; in a polyol-sweetened one, carbohydrate stays high while sugars collapse to near zero. EU labels may add an explicit "of which polyols" line, and US labels sometimes list sugar alcohols separately. Two practical consequences:

• Calories survive. A 40 g portion of maltitol-sweetened chocolate typically saves only 60 to 80 kcal versus regular chocolate, not the "guilt-free" difference the packaging implies.
• Net carbs get murky. Keto arithmetic often subtracts all polyols, but only erythritol deserves full subtraction; maltitol is partially absorbed and should count at roughly half. The details live in the net carbs explainer.

Blood sugar: not all polyols are equal

Glycemic response varies widely across the family. Erythritol is absorbed but not metabolised and excreted unchanged, so its glycemic index is effectively zero. Xylitol sits low, around 13. Maltitol, the workhorse of sugar-free confectionery because it behaves most like sugar, has a GI in the region of 35, roughly a third of glucose. For people with diabetes this matters: a maltitol bar is meaningfully gentler than sugar, but it is not inert, and treating it as free is a common source of unexplained readings.

The laxative warning is not a formality

Polyols are incompletely absorbed in the small intestine. What is not absorbed travels onward, draws water into the gut and ferments, producing gas, bloating and, at higher doses, diarrhoea. Sensitivity varies, but for many adults problems start around 20 g of sorbitol or maltitol in a sitting, which is two or three rows of sugar-free chocolate. EU regulation requires the phrase "excessive consumption may produce laxative effects" once a product exceeds 10% polyols. Erythritol is again the mild one, since most of it is absorbed and excreted before reaching the colon. If you follow a low-FODMAP approach for IBS, note that polyols are the P in FODMAP and are usually restricted.

Bottom line

Sugar alcohols are a genuine improvement on sugar for teeth and a partial one for calories and blood glucose, with maltitol the weakest saver and erythritol the strongest. Read the carbohydrate line rather than the sugar-free banner, count roughly half calories and half carbs for most polyols, and respect the 20 g comfort limit. To see whether a sugar-free product actually beats its regular twin, put both labels side by side in the comparison tool.