WebMD states that sugar, added sugars and refined white grains are bad carbohydrates. Sugars considered bad carbohydrates include processed sugars, and added sugars include sugars to added meals and beverages after preparation. Refined white grains are foods made with white flour, such as bagels and white hamburger buns.
WebMD defines sugars that contain bad carbohydrates as the sugars that do not provide natural fructose, such as those found in fruit. USDA research states that the average adult takes in 320 calories with no nutrients in their daily tasks by adding sweeteners to their coffee, tea and other prepared meals. The high carbohydrate count of refined white grains serves as a quick energy boost, but provides an insufficient amount of fiber.