I agree with Needles. We need to put the responsibility back on the parents where it belongs. When I was in elementary school (I'm only 43 so it wasn't that long ago) we didn't even have a lunch room. We went home for lunch. We ate breakfast at home as well. Our parents didn't expect the school to be responsible for feeding us.
Now, the schools are expected to provide breakfast and lunch. At my school, we have universal breakfast which means every kid is allowed to eat a school provided breakfast for free. Yes, school breakfasts and lunches could be much healthier but I understand why they buy the processed stuff. In almost every case, the processed food is cheaper to buy in bulk. When you're responsible for feeding so many kids you have to do it as cheaply as possible.
Kids are a lot lazier (for lack of a better word) than they used to be. We were almost never inside during the day. We rode bikes, ran around, played outside. Parents today don't unplug their kids and send them outside.