As recently many studies on the relationship between excessive sugar intake and chronic disease have been reported across the world, more attention to sugar intake has been paid. Sugars, called simple sugars, is a kind of carbohydrate and sum of monosaccharides and disaccharides. Sugars that are particularly related to health are added sugars or free sugars, which are added to food by processing or cooking. It is generally not to give satiety and increases energy density without other nutrients. Especially, the major food source of added sugar is sugar-sweetened beverages(SSBs), from which sugars are closely linked with health outcome. The total sugar intake in Korea is 61.4 g per day and it is almost half of those in the western countries such as the U.S. or Australia and it is within the recommendation level by the Dietary Reference Intakes for Koreans. However, when it is classified by age groups or food sources, sugar intake in adolescents and young adults are high and the sugar from processed foods is also high that would lead to high intake levels of added sugar. Particularly, the frequency of SSBs, the major food source of added sugar, is the highest among 20's. While the studies of excessive sugar intake with chronic diseases including obesity, type 2 diabetes, metabolic disease, cardiovascular disease reported in the Western populations, those in the Korean populations have just started. Given our dietary practice is very different from those in the western population, more prospective studies would be necessary to evaluate sugar intake by type or food source exactly and examine its relationship with chronic diseases in the Korean population.