When I was 14, I hadn't grown much at all, I only really started growing when I was 16, same with my brother and my father. As long as your son doesn't smoke (anything) cause that will stunt his developments and he should get plenty exercise (it increases testosterone), take zinc (very important) and take a multi-vitamin. These are the most important years for his body and brain, he will never get a chance to go through puberty again and correct all these mistakes. Exercise is not negotiable, it is the cure for being an awkward teenager: It is good for the major brain developements that happen during puberty, it increases testosterone which is magical mootie for males, it causes one's brain to produce 'happy' chemicals, it gives one a positive body image which is 1 step closer to feeling really good about oneself(NB).