Not much can be done to increase your height, especially at certain ages. Although there are factors that contribute to one's height, these factors range from nutrition to genetics. Height is basically determined by your genetics; genetics covers about 60 - 80% of the height, while the remainder of the percentage that is not covered by hereditary is environmental, the main factor being nutrition. Various researchers have found out that as nutrition is improved, as time goes by, people have grown taller. Instance after 18, even a person taking a balanced diet might not observe an increase in his height.
This is because of the growth plates responsible for height. The plates are cartilage towards the end of one's long bones. Height increase is because of the lengthening of one's long bones as the growth plates are very much active. Towards the end of puberty, some hormonal changes begin to occur, which causes the growth plates to become harden, thereby stopping the lengthening of bones.
There many people that are not happy with their height, but is there anything they can do about it? As you grow older, your chances of growing taller get slimmer. For most people, you cannot increase your height after age 20, whether you eat healthy, exercise, or stretch techniques or not. The reason why you cannot grow taller is that the growth plate of your bones is no longer active, so the length of your bone stops increasing. Normal, during childhood and early puberty stage, your growth plate, also known as the epiphyseal plate, is active and open. Towards the end of puberty, the hormonal changes in the body cause the growth plates to close, and the bone stops increasing in length. However, people suffering from the condition known as gigantism are extremely tall due to the production of excess growth hormone in the body.