I’ve personally found that when I’ve got a full fridge it’s overwhelming so I try and keep the amount of stuff in my fridge as minimal as possible and aggressively consume leftovers. With a roommate/partner/etc you’ve got less control so you need to sort of trust them to do the same or else look at some alternative arrangement… in uni I was subletting a super sketchy place about a block and a half from a supermarket so I just bought what I needed to cook fresh and got a shitty little mini fridge to keep leftovers in my bedroom.