The following foods are allowed in a clear liquid diet: Water (plain, carbonated or flavored) Fruit juices without pulp, such as apple or white grape. Fruit-flavored beverages, such as fruit punch or lemonade. Carbonated drinks, including dark sodas (cola and root beer) Gelatin.
Your body has a mechanism and set of enzymes for digesting the carbs, protein and fat molecules in your food. Chemical digestion occurs in several steps beginning in the mouth and ending with absorption in the small intestinal cells.
Carbohydrates and the Brain. The main function of carbohydrates in your diet is to provide energy and fuel to your body, especially your brain. Carbohydrates break down into glucose in your body, which is then used as energy. Complex carbohydrates are carbs that break down more slowly in your system, providing a more gradual energy source than simple carbohydrates, which can cause spikes to your blood sugar and energy levels.