Sugar alcohols are lower in calories and have a much smaller effect on blood sugar than regular sugar, which makes them a reasonable swap for many people. But “better” depends on what you’re optimizing for. Sugar alcohols come with their own trade-offs, including digestive side effects and, in at least one case, emerging cardiovascular concerns that are worth understanding before you make the switch.
How Sugar Alcohols Compare on Calories
Regular sugar (sucrose) delivers about 4 calories per gram. Most sugar alcohols land between 1.5 and 3 calories per gram, with erythritol at the low end providing essentially zero usable calories. That calorie reduction is real, but it’s not as dramatic as you might expect from products marketed as “sugar-free.” Maltitol, one of the most common sugar alcohols in candy and baked goods, still packs roughly 2.7 calories per gram. If you eat a full bag of maltitol-sweetened chocolate, you’re still taking in a significant amount of energy.
It’s also worth noting that sugar alcohols are generally less sweet than sugar. Xylitol is the closest match at about the same sweetness level, while sorbitol and maltitol are roughly 60 to 90 percent as sweet. Erythritol is only about 70 percent as sweet. Manufacturers often compensate by using more of the sugar alcohol or blending it with other sweeteners, which can offset some of the calorie savings.
Blood Sugar: Where Sugar Alcohols Clearly Win
This is the strongest argument in favor of sugar alcohols, especially if you have diabetes or insulin resistance. The glycemic index (GI) measures how much a food raises blood sugar on a scale where pure glucose scores 100. Regular table sugar scores around 65. Sugar alcohols score dramatically lower:
- Erythritol: GI of 0 to 1
- Mannitol: GI of roughly 2
- Sorbitol: GI of 4 to 9
- Xylitol: GI of 7 to 13
- Maltitol: GI of roughly 35
Erythritol barely registers on blood sugar at all. Even maltitol, the highest of the group, still causes less than half the blood sugar spike that table sugar does. For people managing type 2 diabetes or trying to reduce insulin spikes throughout the day, this difference is meaningful. That said, maltitol is high enough that eating large portions of maltitol-sweetened foods can still raise blood sugar noticeably, something people with diabetes sometimes learn the hard way.
Dental Health: A Real Advantage
Sugar feeds the bacteria in your mouth that cause cavities. Those bacteria break down sugar, produce acid, and that acid eats away at tooth enamel. Sugar alcohols short-circuit this process because cavity-causing bacteria can’t efficiently metabolize them. Without that breakdown, the bacteria produce far less acid, and plaque pH doesn’t drop low enough to damage enamel.
Xylitol appears to go a step further than other sugar alcohols. Research from the American Academy of Pediatric Dentistry suggests that habitual xylitol use may actually reduce the levels of cavity-causing bacteria in plaque over time. The bacteria that survive in a xylitol-rich environment seem to produce weaker, less sticky plaque that doesn’t adhere as well to teeth. This is why xylitol shows up in so many sugar-free gums and mints: it’s not just neutral for your teeth, it’s actively protective.
Digestive Side Effects
Here’s where sugar alcohols lose points. Most sugar alcohols are poorly absorbed in the small intestine. They pass into the large intestine, where gut bacteria ferment them, producing gas. The result, especially if you eat too much, is bloating, cramping, and diarrhea. Products containing sorbitol or maltitol are required to carry a “may cause a laxative effect” warning in many countries for this reason.
Erythritol is the exception. About 90 percent of it is absorbed in the small intestine and excreted through urine, so it causes far less digestive distress than other sugar alcohols. Most people can tolerate reasonable amounts without any GI symptoms. Xylitol falls somewhere in the middle: it’s better tolerated than sorbitol or maltitol but can still cause problems at higher doses, typically above 30 to 40 grams per day.
Tolerance tends to build over time. If you’re switching to sugar alcohol-sweetened products, starting with smaller amounts and increasing gradually gives your gut a chance to adjust.
The Erythritol Heart Risk Question
A 2023 study published in the American Heart Association’s journal raised a concern that caught many people off guard. Researchers found that when healthy volunteers consumed 30 grams of erythritol (roughly the amount in a couple of erythritol-sweetened drinks), their blood levels of erythritol increased more than 1,000-fold. More concerning, this spike was linked to enhanced platelet reactivity, meaning blood platelets became more responsive to signals that trigger clotting. Glucose, given in the same amount, did not produce this effect.
The worry is that increased platelet reactivity could raise the risk of blood clots, which can lead to heart attacks or strokes. This research is still early, and it studied a single dose in a controlled setting rather than tracking long-term outcomes. But it’s a significant enough signal that people with existing cardiovascular risk factors should be aware of it. Erythritol had previously been considered the safest sugar alcohol because of its near-zero calorie count and minimal digestive effects, so these findings have complicated the picture considerably.
What About Weight Loss?
Many people reach for sugar-free products hoping to lose weight, and the logic seems straightforward: fewer calories in, less weight gained. In practice, the evidence is less encouraging. The World Health Organization released a guideline in 2023 advising against using non-sugar sweeteners for weight control, noting that long-term studies don’t show a clear benefit for body weight management. Their broader recommendation: reduce the overall sweetness of your diet rather than swapping one sweetener for another.
That guideline specifically exempted sugar alcohols from its scope, classifying them separately from non-nutritive sweeteners like aspartame or stevia because sugar alcohols do contain some calories. Still, the underlying principle applies. If replacing sugar with sugar alcohols just maintains your preference for intensely sweet foods and drinks, it may not change your eating habits in a meaningful way. The calorie reduction per serving is real, but it’s modest enough that overall dietary patterns matter more.
Which Sugar Alcohol Is the Best Choice?
There’s no single best option because each sugar alcohol has a different profile of benefits and drawbacks. Xylitol is the strongest choice for dental health and has a moderate glycemic index of 7 to 13. Erythritol has the lowest impact on blood sugar and causes the fewest digestive problems, but the emerging cardiovascular data introduces uncertainty. Maltitol is the most common in packaged foods because it behaves most like sugar in cooking and manufacturing, but it has the highest glycemic index of the group and is notorious for causing digestive issues.
For most people, sugar alcohols are a reasonable alternative to sugar in moderate amounts, particularly for blood sugar management and dental health. They’re not a free pass, though. The digestive effects are real, the calorie savings are smaller than many assume, and the long-term safety picture, especially for erythritol, is still developing. The simplest advice remains the least satisfying: using less sweetener overall, regardless of type, does more for your health than finding the perfect sugar substitute.