You could amend it to say "while school is in session". Also, any food made at the school or central facility specifically for the school would be exempt. Everyone needs a soft m&m cookie now and then.
Yes, those cookies are to die for, especially when they're greasy enough to melt through the napkin...
BUT, I have to say, that's sort of why I put this clause in the bill. Isn't it a good idea to stop selling this stuff on the premises? If kids want it they can go off-property.
Kids are not allowed off property. And having a cookie with your lunch isn't going to kill them.
What kills them is washing it all down with 20oz of coke or a package of powdered mini donuts that features mechanically separated beef and enough preservatives to preserve a small mammal for eternity.