Relationship breakdown, divorce and problems at work commonly affect families with eating disorders and only a small proportion get the support they need from health services, according to a survey.
In the survey, by Britain's leading eating disorders charity BEAT, 79 percent of families affected by eating disorders said they had caused lasting damage to their lives.
Some 1.1 million people in Britain are affected by anorexia, bulimia or binge eating, BEAT said in the survey published at the start of eating disorders awareness week.
Twenty percent of anorexia sufferers die, the highest mortality rate of any mental illness, BEAT said.
Guidelines on the treatment of eating disorders and on the need to involve family members in therapy - published in 2004 by the National Institute of Health and Clinical Excellence (NICE) - are not being followed, BEAT said.
"The cost of continuing to fail families is too high. Too many lives are damaged and destroyed by this most deadly of mental illnesses," the charity said in its report.
Only 12 percent of families, of 500 surveyed across the country, felt they had access to the support they needed and 23 percent had no support at all.
"We are shocked at their response and moved by the efforts they have to make to fight for the support that is theirs by right," BEAT added.
The survey found 35 percent of families felt excluded by the hospital from the care and treatment of the affected relative and only 45 percent were offered family therapy - the evidence-based treatment of choice.
Affected families talked about relationship breakdown and divorce, problems at work because of the need to provide care, visit hospitals or attend therapy, the impact on other children, damaged friendships and lives put on hold for years.
BEAT called on all doctors to provide basic information and improve their knowledge of eating disorders and for families to be given the right support and access to specialist treatment.
Members of Parliament, in response to the survey, said more needed to be done to ensure families had the information and support they needed.
"This report highlights how far we need to come to ensure the right information and support is available to the thousands of families around the UK caring for someone with an eating disorder," said Labour's Ian Gibson.
