Our school canteen have unhygenic food. But many students don't think about this and almost everyday eats junk food which is harmful for the health of students. The students sometimes have a big reason, but sometimes only because of habbit they do this. 
I have three different examples. One, his mother had died at his birth time. Because his father can't make food at morning, therefore he had to eat.
But second student had both mother and father, but he denies to take food for his school lunch. And it junk food in school. third one also have both but his parent don't make lunch for him.
These three situations tell much about the reasons behind eating of unhygenic food. But the school should provide hygenic food in canteen so that the students will take a healthy meal. Also stundents should understand about this.