I think some extra warning could be added by adding an extra status. And I'd also add in some negative effects to worse levels of hunger prior to starvation, if they're not already present (I don't spend much time in hungry states except where I have no choice, which usually results in death, so I don't know what effects might already be present).
Anyway, here's what I'd have:
Normal
Hungry (no negative effects, just a warning) - kicks in much earlier than the current "Hungry" state.
Famished - kicks in where the current "Hungry" state does, causes some minor To and St abuse.
Ravenous - kicks in where "Hungry!!" currently does, causes significant To and St abuse, and minor abuse to Le, Dx, Wi, and Ap.
Starving - unchanged from the current setup, except adding further stat abuse beyond the temporary stat drops.