The kids will just go to costco and buy their M&Ms in bulk, keeping them in their locker all semester and eating even MORE than if they had to buy each pack individually.
True.
My HS did this (20cough) years ago. Banned the juice machine because of the "High Sugar Content".
Kids cut class (!) to walk down to the local convenience store and buy soda (!) instead. It was cheaper than the machine, anyway.
Some kids, though I can't even conceive of such a thing (/s), would pick up a pack of smokes, too, and grab a butt on the walk back to school.
Unintended consequences, and all that. :-)