Actors onscreen usually don't really eat the food. It's usually fake food that's been created to look perfect, because real food doesn't do well under camera lighting. Fake food can look fresh all day. And if they bit into a sandwich they'd need a new sandwich for each retake. The actors would also gradually get full, and spills would cause costume and set problems. Some directors do real food but generally it's just asking for trouble. And actors certainly don't do real laundry or other domestic things on camera lol. Sppliances usually aren't even plugged in. It's all phony.

There was one famous heartwarming Coke commercial where a kid gives his Coke to a tired football player, who downs it and then tosses the awestruck kid his jersey. I remember the player saying they did 15 or 16 takes and he drank the whole Coke each time.