Erythritol is a sugar alcohol used as a low-calorie sweetener. It occurs naturally in some fruits and fermented foods and is about 70% as sweet as sucrose (table sugar) but contains almost no calories. Erythritol is popular in sugar-free and reduced-calorie products due to its ability to mimic the sweetness of sugar without significantly raising blood sugar levels. It is generally recognized as safe by regulatory agencies and has minimal digestive side effects compared to other sugar alcohols.