What are sugar alcohols?
Sugar alcohols — erythritol, xylitol, sorbitol, maltitol and isomalt — are neither sugars nor alcohols in the everyday sense. This is a plain, sourced guide to how they are built, how the body handles them, and the two cautions worth knowing.
At a glance
What a sugar alcohol is
A class of carbohydrate whose chemical structure carries features of both a sugar and an alcohol — which is where the name comes from — but which is neither table sugar nor the alcohol in drinks.
Sugar alcohols, or polyols, occur naturally in small amounts: sorbitol in some fruits, erythritol in grapes, melons and fermented foods, xylitol in fibrous plants and hardwoods. Most of what reaches food is produced industrially. They are used as bulk sweeteners — they add sweetness and body the way sugar does — and because they are less sweet than sugar, they are often blended with a high-intensity sweetener to round out the taste.
Why they're only partly absorbed
The small intestine absorbs polyols slowly and incompletely. The portion that is not absorbed passes to the colon, where gut bacteria ferment it. That is why sugar alcohols deliver fewer calories than sugar — and why, in larger amounts, they can cause gas, bloating or a laxative effect. Tolerance varies by polyol and by person; erythritol, which is mostly absorbed and then excreted unchanged, is generally the best tolerated.
The common sugar alcohols
The five with a dedicated Zero Sugar Facts page, with their FDA caloric factors. Sweetness is given relative to table sugar.
| Sugar alcohol | Calories (FDA factor) | Sweetness vs. sugar | Typical use |
|---|---|---|---|
| Erythritol | 0 kcal/g | ~60–70% | Widely used in low- and no-sugar foods; often blended with monk fruit or stevia. |
| Xylitol | 2.4 kcal/g | ~100% (as sweet) | Sugar-free gum, mints and oral-care products. |
| Sorbitol | 2.6 kcal/g | ~60% | Sugar-free candy and gum; carries the FDA laxative warning above a threshold. |
| Maltitol | 2.1 kcal/g | ~75–90% | Common in sugar-free chocolate and candy. |
| Isomalt | 2.0 kcal/g | ~45–65% | Mainly hard candy and lozenges. |
Two more polyols appear often but have no page here: mannitol (1.6 kcal/g), which shares the laxative warning with sorbitol, and lactitol (2.0 kcal/g).
Calories, labeling and tolerance
How the FDA counts sugar alcohols, where they appear on the label, and the cautions the agency attaches to them.
| Point | What the FDA says |
|---|---|
| Calorie values | General factors range from erythritol at 0 to sorbitol at 2.6 kcal/g — below sugar's 4 kcal/g (21 CFR 101.9). |
| Where on the label | Listed under Total Carbohydrate, not on the Added Sugars line. The gram amount is voluntary unless a claim about sugar alcohols or sugars is made. |
| Laxative warning | Foods where sorbitol or mannitol could be eaten in quantity must state "excess consumption may have a laxative effect." |
Digestive tolerance. Introduce sugar alcohols gradually; the unabsorbed portion fermented in the colon is what causes gas or a laxative effect in larger amounts. Erythritol is generally the best tolerated.
Dogs and xylitol. Xylitol is dangerous to dogs and ferrets, per the FDA. Keep gum, candy, some nut butters and human toothpaste away from pets, and use only pet toothpaste on a dog's teeth.
Common questions
Are sugar alcohols a type of sugar?
No. They are a separate class of carbohydrate. On the US Nutrition Facts label they appear under Total Carbohydrate, not on the Added Sugars line, and they provide fewer calories than sugar.
Do sugar alcohols raise blood sugar?
Less than sugar does, and the amount varies by polyol — erythritol has a negligible effect, while maltitol is higher. See the page on sweeteners and the glycemic index for how they compare.
Why do sugar alcohols sometimes cause stomach upset?
Because they are only partly absorbed. The portion that is not absorbed is fermented by bacteria in the colon, which can cause gas, bloating or a laxative effect when intake is high.
Are sugar alcohols safe for dogs?
Xylitol is dangerous to dogs and ferrets and can be life-threatening, according to the FDA. Keep any product containing it — gum, candy, some nut butters, human toothpaste — out of a pet's reach.
Selected sources
- US FDA, 21 CFR 101.9 — general caloric factors for sugar alcohols and nutrition-labeling rules.
- US FDA Nutrition Facts label guidance — sugar alcohols, including the sorbitol/mannitol laxative warning.
- US FDA Consumer Update — "Paws Off Xylitol; It's Dangerous for Dogs."
See how the sweeteners compare
Sugar alcohols are one family among several. See how the polyols line up against sugar, allulose and the high-intensity sweeteners on calories, sweetness, glycemic impact and baking — all twenty-one side by side.
Open the comparison hub →