Apples contain pectin, which slows digestion, according to a study. Ever heard of “an apple a day keeps the doctor away?” There is a reason for it. Not all calories are created equal and people who ate an apple felt fuller for longer than those who consumed the same amount of calories but from apples juices, which are some of the worst drinks for your body. Apples have simple, quick-burning carbs and complex, slow-burning carbohydrates that will provide optimal amounts of energy.