HGH, Human Growth Hormone, is a driving factor in stimulating the rapid growth that occurs in adolescence. At about the age of 15 HGH production declines. It continues to decline throughout adulthood.
There are also a variety of genetic, dietary, and lifestyle factors that can impact HGH production. As for diet, one study in particular assessed carbohydrate intake. This means a high carbohydrate diet produced low HGH specifically for men in the study. Additionally, poor sleep has been linked to low HGH production. Subjects with a normal sleep time had peak of up to 6 times more HGH than those subjects with a delayed sleep time. Sleep is directly related to the amount of HGH secreted by the pituitary. Emerging research has also indicated traumatic brain injury as a potential disruptor of HGH production.