The process by which the body converts food into energy is called metabolism. This complex series of chemical reactions breaks down food into usable energy, primarily in the form of ATP (adenosine triphosphate). Metabolism encompasses both anabolism, the process of building up molecules, and catabolism, the breaking down of molecules for energy. The efficiency of metabolism depends on various factors, including age, activity level, and individual health. Optimizing metabolism through nutrition and exercise can enhance energy levels and overall health.