Energy bars are supplemental bars containing high energy ingredients to provide require quick energy if a meal is not available.
To provide energy quickly, most of the carbohydrates are various types of sugars like fructose, glucose, maltodextrin, dextrose and others in various ratios. Use of complex carbohydrates are reduced. Proteins come mostly in the form of fast digesting whey protein. Energy bars generally don't contain sugar, since these bars, due to type of carbohydrate content, don't require low calorie sweeteners to improve their taste.