Sugar Alcohols Explained: Erythritol, Xylitol, Maltitol — What's Safe?

Sugar alcohols (polyols) are a class of sweeteners used in nearly every 'sugar-free' or 'low-sugar' snack. They taste sweet like sugar but provide fewer calories and don't spike blood glucose the way sugar does. They are not alcohol in the drinking sense — the name refers to their chemical structure.

Not all sugar alcohols are created equal. Some are well-tolerated; others are infamous for causing gas, bloating, and diarrhea. Here's the breakdown.

Erythritol: The best-tolerated sugar alcohol. About 60–80% as sweet as sugar, with only 0.2 calories per gram (sugar has 4). 90% is absorbed in the small intestine and excreted in urine — meaning very little reaches the colon to cause GI issues. A 2023 observational study linked high blood erythritol levels to cardiovascular events, but causality is hotly debated and the doses studied were far above typical intake. Most relevant for our purposes: erythritol is the polyol least likely to cause digestive upset.

Xylitol: As sweet as sugar, with about 2.4 calories per gram. Well-tolerated in small amounts; causes GI issues in larger doses. Notable bonus: xylitol prevents tooth decay, which is why it's common in sugar-free gum. Critical warning: xylitol is highly toxic to dogs. Keep it away from pets.

Maltitol: The one to avoid. Commonly used in cheap 'sugar-free' protein bars and chocolates because it has a sugar-like mouthfeel. Maltitol has a glycemic index of 35–52 (sugar is 60), so it does spike blood sugar meaningfully. It's also the most notorious sugar alcohol for causing gas, bloating, and diarrhea. If a product leads with maltitol, treat it with suspicion.

Sorbitol and mannitol: Less common in modern products. Both are known GI irritants in moderate doses. Found in some older 'diet' foods.

Allulose: Technically a 'rare sugar,' not a sugar alcohol, but worth mentioning because it's the new gold standard for low-calorie sweetening. 70% as sweet as sugar, 0.4 calories per gram, doesn't spike blood glucose, and digests cleanly. Premium products are shifting to allulose.

Glÿka uses a combination of allulose and natural flavors — no maltitol, no sorbitol, no controversial polyols. We made this choice specifically because GI comfort matters for an everyday product. If your 'sugar-free' snack makes you regret eating it, it's not a habit you'll keep.

Practical advice: when reading a low-sugar product label, scan the ingredients list. If maltitol is in the top three, expect GI consequences. Erythritol, allulose, stevia, and monk fruit are the cleanest options.