Well, if they just called it starvation, nobody would want to do it.
My step-mother ended her life with VSED - Voluntarily Stopping Eating and Drinking - basically starved herself to death. Her illnesses, while debilitating, did not qualify for the Oregon Death with Dignity act, as they were not terminal, and she didn't want to actually commit suicide, so VSED. It was pretty terrible for her, and for us to watch.