If I don't feed my kids breakfast they eat the sack lunch. Gives them a bit more time in the mornings to get ready or build up a little Fun before going to school.
I also ran out of time to get my Sim breakfast before sending her to work, so I had her pack a sack lunch with leftover garden salad, then had her go upstairs at work (she's in the Science career) to eat it, so it saved a few Simoleons. (She's mainly in Science for the chance at more collectibles for the Curator aspiration -- her main interest right now is vampire lore because she's going to be a vampire hunter.)
