Is he too thin? Have you taken him to a doctor for bloodwork to see if he's missing nutrients? Have you explained how nutrients work to him so he understands he can become malnourished if he doesn't eat properly? And if you're the parent and he's the kid, well, maybe the problem is he doesn't get that.
He is not too thin but thinner than average. Yes but we always ended up with a fight when I try to take him to the doctor!!! Because Im having a really busy life since Im running a hotel all alone and really busy with my other son and the 3 year old daughter and I have to run behind her too to feed her. So I hardly find time to be with him.. Yes I always explain him the importance of eating nutritious food but he doesn't care them at all.. When he is at home he is always with the computer or sleeps! So what should I do to make him understand..?