Hi _Annika_, is your game up to date with the latest patch?
What's happening exactly for you? Have you tried things like resetting the Sims, travelling to a different lot and back, and pulling out your mods and CC if you use any? No you don't need to befriend sims to eat food lying around.
I also recommend this gameplay-folder reset as an often-useful glitch-remover if nothing else works:
1. Move (not copy) Saves, Tray, Mods, Screenshots, and Custom Music folders and the Options.ini file to your desktop. Delete the Scratch subfolder from inside Saves.
2. Delete the rest of the The Sims 4 folder from your Documents > Electronic Arts folder.
3. Start the game, and exit the game. Now you have a fresh Documents > Electronic Arts > The Sims 4 folder.
4. Copy all the folders and the file back and start the game again.