@gjammer Starvation is one of the trickiest death types to achieve, so I'm also surprised that it's happened to your sim unintentionally.
In Pinstar's Legacy Challenge, one can score a point for coordinating a specific minimum number of death types so I've tried starving a sim a number of times.
Starvation is so time-consuming that I just skip that death type. Entering CAS or, as Playalot mentioned, traveling to another lot will reset the household sims' needs.
My sims will eat when their Hunger meter is low, even when the club has set "Eat" as a banned activity.
Once a sim gets the "Hungry" moodlet, if they go without eating another 24 hours, they'll get the "Ravenous moodlet.
If a Ravenous sim goes another 24 hours without eating, they'll die of starvation.
If your other households are eating normally, though, perhaps that particular household is glitched.
Did you create those sims yourself or download them from the Gallery?