Glucose metabolism is the process in which your body breaks down glucose (sugar) molecules so it can use them as energy. When you eat something that has sugar in it, your body breaks down the sugar into glucose molecules. Then, your cells absorb the glucose and use it as energy to keep your body running. The cells also turn excess glucose into a type of energy storage, called glycogen. Glycogen is stored in your liver, and your body can use it later when it needs more energy. That's why it's important to eat healthy snacks with a little bit of sugar. It helps your body get the energy it needs.