The gravestone of a starved Sim in The Sims 3.
Starvation occurs when a Sim has gone too long without eating, specifically when their hunger motive has been completely depleted.
The Sims[]
In The Sims, adults, children and pets[TS:U] can all die from starvation (but pets usually run away before it happens). Unlike later games in the series, the player has a bit of leeway when the hunger motive reaches zero. Sims will only starve to death 18 hours after the motive reaches zero.[confirmation needed]
Babies don't have a visible hunger motive, but need to be fed approximately once every 6 hours until they age up. Neglecting one for too long will cause a social worker to arrive and take them away.
The Sims 2[]
In The Sims 2, the ghost of a Sim who died of starvation will be a transparent white. These ghosts will open and close the fridge, and will take food. These ghosts get angry if there is no fridge on the lot or if the fridge is empty. Babies, toddlers, and children cannot die of starvation; they will be removed by the social worker before their hunger drops low enough. Even if testing cheats is used to drag the Hunger motive down to zero, they will not starve. You will also see a Sim wave their arm in the air as a signal that it is expiring.
Starvation can happen from prolonged exposure to an "evil" snapdragon bouquet[TS2:OFB], after a failed wish for money from a wishing well[TS2:S], or when a good or evil witch sits on an opposite-alignment throne for too long[TS2:AL]. However, these things will usually not cause a Sim to starve unless their hunger motive is already low.
The Sims 3[]
In The Sims 3, a Sim starves if they get the "Starving" moodlet, and it expires. Since a Sim will only get this moodlet after the "Hungry" and "Very Hungry" moodlets have expired, starvation takes longer than it does in other Sims games. In The Sims 3, the ghost of a Sim who died of starvation will be purple, and the gravestone of that Sim will have a picture of a knife, fork, and plate on it. When a Sim dies of starvation, their weight will automatically be set to "very thin". It will remain that way even if they are resurrected.
In The Sims 3: Ambitions, a SimBot cannot die from starvation. Upon the Starving motive expiring, a SimBot will instead "short out", which will set the Scrap Reserves motive to 75% upon recovering, well above any sense of feeling hungry. Vampires in The Sims 3: Late Night and The Sims 3: Supernatural also cannot die of starvation, but can die from thirst.
Due to technical limitations, a Sim can only die of starvation when on a lot, as the gravestone can only be spawned on a lot. As a result, Sims do not die in areas that are outside of lots, such as roads. Pregnant Sims also cannot die from starvation. In these cases, when the "Starving" moodlet expires, the timer immediately resets to 7 hours. As a result, players can move starving Sims outside of a lot to prevent death.
With testing cheats on, even if the player drags the hunger need of a baby, toddler, child, or pet down to zero, the Sim will not die, but will be taken away by the social worker instead.
The Sims 4[]
In The Sims 4, starvation works the same way as in The Sims 3, except that it goes through two moodlets instead of three. A hungry Sim receives the "Hungry" moodlet. If hunger is not fulfilled after 24 hours, it changes to the "Ravenous" moodlet, which lasts for another 24 hours. The Sim will then die of starvation after the "Ravenous" moodlet expires. The limitation that Sims can only die on lots has been removed, so Sims can collapse from starvation no matter where they are, including right in the middle of the street. Pregnant Sims, children and younger, pets[TS4:C&D][TS4:HR], vampires[TS4:V], skeletons[TS4:JA], and rampaging werewolves[TS4:WW] cannot die of starvation. Ghosts also cannot die of starvation, as they are already dead.
Bella Goth eating a candy bar to replenish her hunger because she is pregnant.
When a pregnant Sim or ghost's hunger gets too low and they have nothing edible in their inventory, they will pull out what appears to be a candy bar and eat it, replenishing their hunger motive to about 75%. Otherwise if they have food, they will immediately eat it.
Similar to The Sims 2 and The Sims 3, newborns, infants, toddlers, children and pets will be taken away when their hunger motive gets too low.