The bars are usually easy to digest and come in a wide array of flavors and textures. Energy bars are most often associated with top athletes and endurance sports, such as bicycling and running. Some people also eat them as a snack or meal replacement throughout the day. Most energy bars are placed in this group because they are high in carbohydrates and low in proteins and fats. Manufacturers of this type of bar claim that the equal proportion of food groups leads to greater fat-burning during exercise.
Nutritionists tend to favor the high-carbo group.
However, one study showed that runners do not pay attention as much to the overall percentage of carbohydrates in a bar, but to the actual composition of the carbohydrates. Nutritionist Alice Lindeman, Ph.D., R.D., suggests that the blend of carbohydrates should be equal. Fifty percent should be simple carbohydrates which are important for the beginning phase of exercise and are used at a more rapid rate. Several sources of simple carbohydrates include honey, fructose, and corn syrup. Complex carbohydrates are found in maltodextrin, glucose polymers, or unprocessed rice, oats or wheat flour.