Why do schools have horrible fatty lunches?

At my school.....everyday..the only thing you can get is pizza with grease dripping off the side an fries......or nachos with greasy fries.....how come they cant serve like healthy subs or healthy fruits and vegetables everyday......MY SCHOOL HAS SO MANY HUMONGOUS KIDS WITH FLAB ALL OVER THEM AND IT IS DISGUSTING TO LOOK AT......IT DISTRACTS ME......lol