Sugar is an informal term for a class of edible crystalline substances, mainly sucrose, lactose, and fructose characterized by a sweet flavor. In food, sugar almost exclusively refers to sucrose, which primarily comes from sugar cane and sugar beet. Other sugars are used in industrial food preparation, but are usually known by more specific names—glucose, fructose or fruit sugar, high fructose corn syrup, etc.
Excessive consumption of sucrose has been associated with increased incidences of type 2 diabetes, obesity and tooth decay.
Sugar consumption varies from country to country; Brazil has the highest per capita production and India the highest per-country consumption.