Respuesta :

I would say the teen doesn't think of the consequences that not having good health habits maybe affect them in their life later on. Also maybe the parents don't encourage them to live a healthier life. 
Maybe because they weren't inform properly, or maybe they do not know how to practice/do it, sometimes bad things for us are good things for a while, but remember it'll only last a moment and we keep looking for what satisfy us until something really bad happen to us, then we'll stop doing it and wish we didn't do it (too late).