When my daughter started secondary I gave her a small cupboard and baskets in the fridge and freezer so she could make her own breakfast and lunch, including packed lunch:
cereal, cereal bars, croissants
crisps, microwave popcorn, crackers
tinned fruit, salsa, hummus, fresh fruit, cucumbers and carrots
juice, cordial, hot chocolate, coffee when she got older
chocolate, biscuits, treats
super noodles, flavoured microwave rice, tins of pasta meals
bread, wraps
brie, mozzarella, pate, pre-cooked sliced chicken packs, feta, ham
leftovers
pizza, sausages, chicken nuggets
Explained what a balanced meal was and left her to it
Obviously we had a proper evening meal and ate together on weekends, it just took the pressure off me during the week when I was working