I'm 16 years old and my body type is an ecto mesomorph (meaning more ect than meso). I'm 6' 4", a good rugby player tho but i need to put on muscle soon.. I go to the gym but find it hard to put on weight and lose it very quickly. I would like to start taking protein shakes, is it too early and what should I buy. Please no dodgy or unhealthy reccomendations- remember my body isnt yet fully developed.