Sugar alcohols are a type of carbohydrates – “polyols" – and include erythritol, maltitol, sorbitol, xylitol among others. They are not completely absorbed by the body and normally don’t have a big impact on blood sugar levels , so some of them are suitable for keto desserts. That said, the different types of sugar alcohols act in different ways in the body. The downside is that, because our body cannot completely break them down, they can ferment in the gut and cause bloating, gas, or diarrhea.
Erythritol is almost completely excreted in your urine, does not affect blood sugar, has very little calories and also is less likely to cause adverse intestinal symptoms , making it a perfect sugar substitute for keto desserts.
Xylitol’s sweetness is very close to that of sugar but, because of its relatively low glycemic index, it does not affect blood sugar levels greatly. It can help with dental health, may help promote good bacteria in the gut, and has also been linked to increased collagen production . However, it can cause gastric distress, so if you’re considering it for keto desserts or to sweeten a cup of tea it should be used sparingly (it is also extremely toxic for dogs and can be lethal).
Maltitol is also very similar to sugar but with half the calories. The problem is it has a quite a high glycemic index, which means it can cause spikes in blood sugar levels . For this reason, it is not recommended.
Other sugar alcohols include sorbitol, lactitol, glycerol, and isomalt, but these should be avoided because of their effect on blood sugar levels .