Statements like “he can eat a lot because he has a fast metabolism” are somewhat misleading. Metabolism isn’t about the digestion of food in your stomach; it’s the name given to all of the chemical changes that occur in an organism’s tissue cells. There are basically two kinds of chemical changes that can occur;that is tissue matter can be built, or it can be broken down. These processes are called anabolism and catabolism. More specifically, anabolism is responsible for an organism’s growth, its maintenance, and the repair of its tissues. So when you cut yourself and your skin scabs over and heals, you’re seeing anabolism at work. Or if you grow taller or wider, that’s also evidence of anabolism.