C.P.
Honestly, I don't understand why this is a difficult topic. Buy only whole grain breads, lean lunch meats and cheeses, fresh fruit, whole or cut up, and absolutely no junk food. If kids grew up only eating healthy foods from infancy, then this would not be a problem! This includes beverages! No soda! No sugary juices! No cool-aide or anything like that! Kids should be drinking low-fat milk or water with meals. Other ideas: homemade soups, salads with simple, homemade dressings, pasta salads made with whole grain pastas, cereal or granola bars, whole grain crackers...
My family just returned from staying with friends out of state for the weekend, kids the same age as ours, and I was not trilled with the foods she chooses to feed them! French toast sticks that were nothing but sugar for breakfast, no fruit to speak of except apple sauce or canned peaches... and it went on from there... also she let the kids eat constantly throughout the day, whatever they wanted, from popcorn at breakfast to candy and chocolate throughout the day/night.. and even sugary snacks at bedtime.
Schools should address this issue! I'm glad that yours is : ) Good luck!