First of all, where did bạn read that? I have never read hoặc seen that the boys were forced to lose weight and if they do that, i suppose its their management who is thêm concerned about their image than their music.
Secondly, they will NEVER end up like Michael Jackson because they arent (no offence to the những người hâm mộ of the king of pop) crazy dark skin people who think being white is going to stop criticism and racism. Sorry again to the những người hâm mộ but thats my opinion :(
Again, the boys are healthy and im quite sure if they exercise is for their own good