Malissa Jones is living proof of the saying "Be careful what you wish for."
Jones was just 17 when she underwent gastric bypass surgery.
At first, it was a dream come true as the weight melted off her.
But now she's been diagnosed as anorexic.
She weighs just 120 pounds, and 40 pounds of that is the flabby skin left from her time as an obese young woman.
She has lost most of her hair, her teeth are shot, and she can barely force herself to eat.
A typical meal at her home in England is buttered toast.
"This is a bleak, bleak picture, and it's heartbreaking," says Los Angeles psychotherapist Dr. Mike Dow, who thinks Jones's excess skin is a major issue.
"One of the things we see in anorexia is, no matter how thin a person becomes, the person always sees fat in the mirror. So I'm sure that for Malissa having 40 pounds of excess skin hanging on her, that contributes to that."
Doctors say Jones is wasting away and has only six months to live if she doesn't start eating more.
She told INSIDE EDITION she rues the day she had the surgery.