What type of energy is associated with food? how is that energy stored? how does food energy change when it is used to do work

Chemical energy is associated with food. It is stored in the chemical bonds of atoms and molecules. It can only be seen when it is released in a chemical reaction. When chemical energy is released, the substance from which the energy came is often changed into a different substance. When the stomach digests food, the carbohydrate in the food breaks down into another type of sugar called glucose.