Emily Troscianko's anorexia was so severe that when she was 26 she was barred from a treatment program because her weight had dropped so low. Therapists said she was a medical liability; they were afraid she might collapse at any time.
Her mother, Susan Blackmore, tried everything she could. Then, by accident, she spoke some honest, harsh words.
"Your anorexia is not welcome at my house… I'm not having your anorexia wrecking my new home," Blackmore says she told her daughter, who is now 28. Emily was finishing her postgraduate studies in German at Oxford University at the time, and often came home during breaks.
When Blackmore and her partner, Adam Hart-Davis, moved from Emily's childhood home she decided she wanted Emily in her new house, but did not want to shelter her anorexia.
"For both of us it was a really pivotal statement, a turning point," said Blackmore."I liken it to the dementors in Harry Potter -- she would walk through the house and you could feel the cold.... you felt as though all the energy was being sucked out of you because of this waif."
At the time Troscianko didn't take her comment well. "I thought 'She's being stupid, how could she think that there is a me that isn't an anorexic me' because that was my whole identity then," said Troscianko. "It did make me think and it did make me upset and scared of alienating the closest member of my family."
Troscianko gradually began to eat again. She went from 83 pounds to 145 and feels she's finally healthy today.
The family shared their story with the U.K.'s Daily Mail, and Troscianko also writes about recovering from anorexia in her blog, A Hunger Artist, for Psychology Today.
Despite their success fighting anorexia, Blackmore said she'd hesitate to give other parents advice. For years she felt meetings with psychiatrists, in seminars and in treatment groups, didn't give a single good answer. Meanwhile she watched other parents "turn their lives upside down" trying to find the right treatment. A few mothers even quit their jobs to help with their children's treatment.
"My very strong impression is that no one knows what to do," said Blackmore."Nobody knows how to help anorexics get out of it because they don't want to get out of it."
Experts interviewed by ABCNews.com wouldn't go as far to say there's no parental influence -- but they do agree treating an eating disorder can be one of the toughest challenges in therapy.
"The statistics say somewhere between 20-21 percent (of patients) will die of their eating disorder," said Tyler Wooten, a child, adolescent and adult psychiatrist at UT Southwestern Medical Center in Dallas, Texas. Those deaths can be caused by heart irregularities, starvation and suicide.
Wooten thought Blackmore's conversation with her daughter was an example of saying the right thing at the right time, but not so-called tough love.
"They are telling an adult that we love you and we would love to have you in the house for visiting, but if you do not get treatment… you cannot come into our house," said Wooten. "That is an effective thing at her age.