After she died at 15, Liv's heartbroken loved ones have a message about the deadliest mental illness

Robb Evans said his daughter was vibrant and passionate before she lost her life after a battle with anorexia nervosa. (Supplied)

Robb Evans's teenage daughter had been battling an illness with a high mortality rate for a year, but he did not realise its deadliness until the stakes were aired aloud for the first time.

"She has a terminal illness," doctors had told Mr Evans.