Food is digested, or broken down, so that the nutrients can be extracted for use by the body as it passes through the digestive system. If food wasn't digested you would not have energy required to run vital chemical reactions and eventually resulting death
Food has to be digested into smaller component nutrients that are then absorbed and used throughout your body. Calories in food provide your body with the energy it needs to complete vital processes such as cellular maintenance and reproduction, and respiration. also you might get fat and you die
