Growth hormone is a substance that is naturally synthesized in the body of animals and humans by the anterior wings of the pituitatary gland. This substance is used by animals and humans to add body mass, both muscular and skeletal. Growth hormone is used in hormone replacement therapy with children to have disorders of the pituitary gland to help them achieve normal body growth. Growth hormone can be abused as well, most recently in the sporting industry, with athletes trying to increase their size, so as to increase their athletic prowess. Natural ways to increase the amount of growth hormone are to stress the skelto-muscular system with exercise. Lots of resistance training will help build body mass, it provides the input that helps dictate the pace at which the body adds new tissue. A diet that is balanced, but provides the building blocks for those types of tissues would be one that provides plenty of protein, which is what muscle is made of, along with plenty of bone-building sources of calcium and vitamin D.