The only thing about changing foods available is that the kids don't want the food that is good for them.
I've seen it first hand with my kids, friends' kids, co-workers' kids. It's also been widely reported.
So, they eat crappy burgers and fries, or they eat nothing.
Better would be to offer healthy choices and see what sells. Better yet would be to have the kids make their own lunches with ingredients provided.
Maybe a little "home economics" wouldn't hurt.
Is that even taught anymore?