Everyone knows that we eat to give our body energy and raw materials to function, heal, and grow. Even the most avid couch potato burns energy sitting on the couch and watching TV. The human body is a machine, which means it needs energy to operate at all times. A sleeping person may not look like he’s doing much of anything, but there are still brain impulses racing around, the heart is still beating, the lungs are still inhaling and exhaling. Hair and nails are growing, and skin is regenerating. If there’s no energy for the body to operate, none of this will happen. More and more body functions will be cut off in an attempt to conserve power. And as everyone knows, starvation can lead to a great many problems – even before it gets to the point of being life-threatening.