All living organisms need food, unlike green plants, which can make their own food , human and all animals need to obtain food from other living organisms.
The human body obtains the energy and nutrients it needs from food. However, our cells cannot absorb these nutritional benefits until the food has been "digested" - meaning, "processed and converted into a useable form". Thus digestion is the complex process of breaking down food molecules into energy and other useful components, which can then be absorbed into the bloodstream and distributed throughout the body to maintain good health. Food remnants which are not absorbed during the digestion process are expelled as waste in the form of feces.
