how does the body cells get energy from the food we eat?

Answer 1

In all molecules, there is a type of chemical energy called "enthalpy", it is the energy stored in bonds. Think of it this way, all particles want to be free and in motion, in complete disorder, thats the "entropic" nature of the universe. So, it takes energy to make particles stick together (forming compounds and molecules). This energy is stored in bonds, and when the bonds are broken, the energy is released. Our cells have the ability to break these bonds, and utilize this energy.

Think of it this way, glucose is C6H12O6. Our cells can break down all of the bonds in glucose until we form a few CO2 and water molecules. Thats how we get our energy.

Answer 2

Short answer: Energy from food can come from three sources in the food, carbohydrates, fat, and protein. These three can be changed to glucose when the body needs it. Glucose can then enter the cell, and enzymes change it using the glycolysis pathway, which changes it into ATP. ATP can then be used by the parts of the cell that need energy as they need.