A sugar substitute is a food additive that provides a sweet taste without the added calories or negative health effects of sugar. Sugar substitutes are often used as a replacement for sugar in food and beverage products, especially for individuals with diabetes or those looking to reduce their calorie intake. Common sugar substitutes include aspartame, stevia, sucralose, and erythritol. While sugar substitutes are generally considered safe, some individuals may experience adverse effects such as digestive upset or headaches.