In The Sims 2, leftovers in the refrigerator or in a Sim's personal inventory can be stored forever. If leftovers are stored in a refrigerator, they are associated with the lot, not that specific fridge, or even that specific household. They will not be lost if the fridge is sold and replaced. If the household is moved to a new lot, they will not go with it, even if one member takes the fridge in inventory. Instead, they will remain with the lot and will be available if a new household moves in.