Here's why:
* Food is made of molecules: Food is composed of organic molecules like carbohydrates, fats, and proteins. These molecules store energy in their chemical bonds.
* Breaking bonds releases energy: When animals eat, their digestive systems break down these food molecules, releasing the stored chemical energy. This energy is then used for various bodily processes like growth, movement, and maintaining body temperature.
So, the energy in food is essentially potential energy stored in the chemical bonds of the molecules. Animals transform this chemical energy into other forms of energy they need to survive.