Sugar alcohols are a type of carbohydrate used to sweeten candy without regular sugar. Despite the name, they contain neither sugar nor alcohol in the way you’d normally think of those words. They’re modified versions of sugar molecules where one small chemical group has been swapped out, which changes how your body processes them. The result: fewer calories, a lower blood sugar spike, and a sweet taste that works well in candy, gum, and chocolate.
How Sugar Alcohols Differ From Sugar
Regular sugar (sucrose) has 4 calories per gram. Sugar alcohols range from essentially zero calories (erythritol) to roughly 2.4 calories per gram for most others used in Europe, though estimates vary by country. The calorie reduction comes from how your body handles them: your small intestine absorbs sugar alcohols slowly and incompletely. Whatever isn’t absorbed passes into your colon, where gut bacteria break it down. That partial absorption is also why sugar alcohols raise blood sugar far less than regular sugar does.
The glycemic index tells you how much a food spikes your blood sugar on a scale where pure glucose scores 100. Here’s how common sugar alcohols compare:
- Erythritol: glycemic index of 1
- Xylitol: glycemic index of 12
- Sorbitol: glycemic index of 4
- Maltitol: glycemic index of 35
- Mannitol: glycemic index of 2
- Isomalt: glycemic index of 2
- Lactitol: glycemic index of 3
Maltitol stands out as the highest on this list, which matters because it’s one of the most popular sugar alcohols in candy. If you’re monitoring blood sugar closely, maltitol-based products will affect you more noticeably than those made with erythritol or isomalt.
Which Sugar Alcohols Show Up in Candy
Different sugar alcohols have different physical properties, and candy manufacturers pick them based on what the product needs to taste and feel like.
Maltitol is the workhorse of sugar-free candy. It tastes about 87% as sweet as sugar, produces a clean sweetness with very little cooling sensation, and behaves a lot like sugar during manufacturing. You’ll find it in sugar-free chocolate, hard-coated candies, chewing gum, and snack bars. It’s also less prone to absorbing moisture from the air, which helps keep coatings and powdered finishes stable on the shelf.
Xylitol comes in at about 97% of sugar’s sweetness, making it the closest match in taste. It’s especially common in sugar-free gum and mints. Erythritol, at about 63% as sweet as sugar, is often blended with other sweeteners to boost overall sweetness while keeping calories and blood sugar impact extremely low. Sorbitol serves mainly as a bulking agent, helping give candy the right texture and body, and doubles as a humectant that retains moisture. Mannitol produces a noticeable cooling sensation in the mouth and is used in flavor coatings, often in breath mints and similar products. It also resists absorbing moisture, making it useful as an anti-caking agent.
The Dental Benefit Most People Don’t Expect
One of the more surprising things about sugar alcohols is that some of them actively protect your teeth. Regular sugar feeds the bacteria in your mouth that produce acid and cause cavities. Xylitol and erythritol do the opposite: they inhibit the growth of the main cavity-causing bacterium, Streptococcus mutans.
Xylitol reduces the amount of dental plaque and makes the plaque that does form less sticky and less able to cling to teeth. It does this partly by starving the bacteria (they can’t use xylitol for energy the way they use sugar) and partly by altering how the bacteria produce the sticky substances they use to anchor themselves. People who regularly consume xylitol have measurably lower plaque levels than non-consumers. Erythritol shows similar effects, particularly in disrupting the early stages of bacterial film formation on tooth surfaces. This is why xylitol-sweetened gum is specifically recommended by many dental organizations.
Why Sugar-Free Candy Can Upset Your Stomach
If you’ve ever eaten too many sugar-free gummy bears and regretted it, sugar alcohols are the reason. Because they’re only partially absorbed in the small intestine, a significant portion reaches your colon intact. There, gut bacteria ferment them, producing gas. Consume enough, and the unabsorbed sugar alcohols also draw water into the intestine through osmosis, which can cause bloating, cramping, and diarrhea.
The threshold varies by person and by sugar alcohol. In clinical testing, sorbitol and lactitol both triggered diarrhea at doses around 70 to 75 grams per day, though 40 grams per day of lactitol was well tolerated without symptoms. Most people notice discomfort somewhere in the 10 to 30 gram range for sorbitol and xylitol, especially if they aren’t used to eating them. Erythritol is the gentlest option because about 90% of it gets absorbed in the small intestine and excreted through urine before it ever reaches the colon, so it causes far less fermentation and gas.
Your tolerance tends to improve over time. If you start eating sugar alcohols regularly in small amounts, your gut bacteria adapt and the side effects often diminish. The practical advice: don’t eat an entire bag of sugar-free candy in one sitting, and pay attention to which sugar alcohol the product contains if you’re prone to digestive issues.
How to Spot Sugar Alcohols on a Label
Sugar alcohols are easy to identify in an ingredient list because their names almost always end in “-itol”: maltitol, sorbitol, xylitol, erythritol, mannitol, isomalt (the one exception to the naming pattern), and lactitol. On a Nutrition Facts panel, sugar alcohols appear indented under “Total Carbohydrate,” listed in grams per serving. If a serving contains less than 0.5 grams, the label can list it as zero.
Interestingly, listing sugar alcohol content is technically voluntary under FDA rules, with one catch: if the product makes any claim about sugar content (like “sugar-free” or “no sugar added”), the sugar alcohol grams must be declared. So any candy marketed as sugar-free will show this line on the label. Keep in mind that sugar alcohols still count as carbohydrates. If you’re counting net carbs, many people subtract sugar alcohols from total carbs, though maltitol’s higher glycemic index means it behaves more like a regular carbohydrate in your body than erythritol or isomalt would.
Sugar Alcohols vs. Artificial Sweeteners
Sugar alcohols and artificial sweeteners both replace sugar, but they work very differently. Artificial sweeteners like aspartame and sucralose are intensely sweet in tiny quantities and add essentially no bulk to a product. Sugar alcohols are less sweet than sugar, gram for gram, and provide physical bulk, texture, and mouthfeel. That’s why candy uses sugar alcohols: you need a substance that can form a gummy bear, coat a chocolate bar, or create a hard candy shell. Artificial sweeteners alone can’t do that.
Many sugar-free candies use both. A sugar alcohol provides the structure and most of the sweetness, while a small amount of an intense sweetener rounds out the flavor. If you see both maltitol and sucralose on a label, that’s what’s happening.