Leftover

Beginning with The Sims 2: Seasons, a Sim can store leftovers by putting them into the refrigerator. The feature is also in The Sims 3 and The Sims 4.

The Sims 2

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.

Since The Sims 2: Kitchen & Bath Interior Design Stuff is based on The Sims 2: Pets, the new refrigerators included with it do not have the ability to store leftovers. Fixes are available at ModTheSims:

Fix for players who do not have Apartment Life or Mansions & Gardens

Fix for players who have either Apartment Life or Mansions & Gardens

The Sims 3

In The Sims 3, leftovers will go bad over time in the refrigerator. Also, eating leftovers from a cheap refrigerator might give a negative moodlet. Stored leftovers can be taken as single plates straight while the group meal remains inside. Reaching level 10 in the Culinary Career rewards the Sim with a Master Chef Fridge that keeps food indefinitely.

The Sims 4

In The Sims 4, leftovers in refrigerators will stay as good quality forever and can be cleaned by Sims after all of the servings have been eaten, though they won't do this autonomously. The "Get Leftovers" interaction will make Sims take any random leftover that is inside the fridge.