Xylitol has a similar level of sweetness to sugar but with a fraction of the calories. It is a popular ingredient in a variety of products. Xylitol has a low glycemic index (GI). This means that consuming it does not cause spikes in blood glucose or insulin levels in the body. Xylitol is a reduced-calorie sugar substitute similar in sweetness to table sugar. Xylitol also has a low GI, which makes it an attractive alternative to sugar for people wishing to lose weight and those with diabetes.