Sugar alcohols are naturally occurring, sweet-tasting carbohydrates. They are often used in place of sugar (sucrose) in food products and recipes to reduce calories and the glycemic response.
There are many different types of sugar alcohols: mannitol, sorbitol, xylitol, erythritol, lactitol, maltitol, isomalt, and hydrogenated starch hydrolysates (HSH). They are easy to identify on food labels as most end in “-itol”. Make note that xylitol is toxic to dogs (1).
When you come across sugar alcohols, you will find that they look very similar to regular sugar. Sugar alcohols are water-soluble, white crystals. But they are not as sweet as actual sucrose. You can purchase sugar alcohols for home use at natural food stores or online.
Some fruits and vegetables do naturally contain sugar alcohols. Industrially produced sugar alcohols, for example mannitol, sorbitol, and xylitol, can be derived from the hydrogenation of sugar (adding two hydrogen atoms). Erythritol is made from fermenting sucrose and glucose (2).
The body does not completely absorb sugar alcohols, which is why they have a lower calorie content than sucrose and keep blood sugars from spiking. See the below graph on the glycemic index of sugar alcohols (3).
Some people can develop digestive issues, such as diarrhea, gas, or bloating, from sugar alcohols. This is due to them not being completely absorbed in the digestive tract. Sorbitol and mannitol tend to give people the most problems, whereas erythritol tends to be tolerated the best (4).
Note that sugar alcohols are not calorie-free like some artificial sweeteners. They still contain anywhere from one and a half to three calories per gram, whereas sucrose has four calories per gram. The one exception is erythritol, which has less than one calorie per gram.
See the chart below (2) to compare the different sugar alcohols.
Erythritol is the winner when it comes to sugar alcohols. It contains the least amount of calories (0 - 0.2 calories per gram), does NOT cause digestive issues, and is almost as sweet as real sugar. It’s the sweetener of choice in Killer Whey!’s Keto Ice Cream.