Children grow rapidly between ages 8-14, gaining height and weight. During this time, girls and boys become more aware of their appearance. Girls worry about weight while boys worry about height. Parents should reassure children that temporary looks are not important, but health is. Genetics influence growth, but good nutrition, sleep, and exercise can help children grow up healthy. Puberty begins between ages 8-13 for girls and later for boys as hormones trigger physical changes that transform children into teens. Changes for girls include breast and body hair development while boys experience voice changes and growth of body hair.