are a category of sugars that contain either one or two molecules
What Are the 3 Types of Carbohydrates? Photo Credit olgakr/iStock/Getty Images. The three carbohydrates -- sugar, starch and fiber -- are all made from molecules of sugar. However, sugar also refers to a type of carbohydrate. Sugars, or simple carbohydrates, contain just one or two molecules of sugar. The complex carbohydrates -- starch and fiber -- consist of many molecules of sugar.