Between 60% and 80% of your height is determined by the DNA that your parents passed down to you whereas about 20% to 40% of your growth is influenced by your own environment. A good diet healthy exercise and lots of sleep can help you get taller in this period than you would otherwise. [1] For most people however growth plates close in their early twenties and after that they are not going to gain any inches naturally. Source: https://www.artikelschreiber.com/en/.