Glucose, also known as blood sugar, is the body's main source of fuel. We get most of it from foods and drinks that contain carbohydrates. When we eat, the digestive system and liver break these foods down and release glucose into the bloodstream, where it becomes available for our cells to take up and use for energy.

Diabetes is what happens when there's too much glucose — sugar — circulating in your blood. That glucose comes from the food you eat, and it's meant to be your body's main fuel.