Protein Necessary for tissue formation, cell reparation, and hormone and enzyme production. It is essential for building strong muscles and a healthy immune system. Carbohydrates Provide a ready source of energy for the body and provide structural constituents for the formation of cells. Fat Provides stored energy for the body, functions as structural components of cells and also as signaling molecules for proper cellular communication. It provides insulation to vital organs and works to maintain body temperature. Vitamins Regulate body processes and promote normal body-system functions. Minerals Regulate body processes, are necessary for proper cellular function, and comprise body tissue. Water Transports essential nutrients to all body parts, transports waste products for disposal, and aids with body temperature maintenance.