What sort of food?
Many, if not most foods sold at room temperature are perfectly fine some time after their date, which is usually a best before (quality) date.
Most chilled foods have a use by date, which is about safety while there's some margin built in to this, no one's going to tell you it's safe to eat things after their use by date, because sometimes it's not. Most home-cooked meals fall into this category. They keep for a few days in the fridge or should be frozen, and can spoil in harmful but not detectable ways. I say "meals" because there are exceptions such as plenty of baked goods, and obviously some home cooking is based on preserving techniques, such as making jam.
It's not really about the ingredients - tinned fish, for example, will keep for years after the best before date, but fresh fish will go off in a few days. Or consider dried fruit vs. fresh fruit. It's about the whole process.