Digestion is the process of taking food and nutrients into the body and making them available for use in all of the body's processes. The digestive system breaks down food and extracts the important nutrients, eliminating the excess substances that cannot be used. These nutrients provide energy for the body to grow, function, and make repairs to itself. "Digestion and Nutrition" describes the path that food takes through the system, the organs involved, and how the body uses different types of nutrients, while highlighting the importance of healthy eating and the problems and diseases that can affect the digestive tract.