Why do people eat food?

People eat food for sustenance and energy.  Food is required to keep us alive and moving about in our daily lives.  It is just as important as water is to our lives.  Your body converts the food into ATP (e.g. energy) for your cells to use.  Nutrients also come from food and help us to grow, and keep the bodily functions working correctly like breathing, digestion, blood flow and the overall health of the immune system.