Food joints should be banned near schools ....

No they should not be banned.

Banning food joints isn't going to stop students from leaving the school.

There is no reason fast food places should be banned around schools. That is just silly. Sure they set up there hoping to attract the kids but they have that freedom. The kids don't have to eat there. And if the schools don't want them eating there then don't allow them off campus. The high school I went to did not allow us off the property. They took attendance at the beginning of every period and if you were caught even in the parking lot (say to get a book from your car) you got an after school detention. Heck you got a detention for being out of the building after the bell rang at the beginning of class. It kept all the students safe.

Banning food joints isn't going to stop students from leaving the school.

Not necessarily....but I think that before opening one the proprietor prepare an outline showing the type of food that it plans to serve and then present it to the local school board approval or disapproval.