Lives are being lost and destroyed by the NHS 'inability to provide care to people with eating disorders, say MPs and activists.
They say that more than a million people have a eating disorder, but that the help of a specialist is often difficult to access.
Patients can only rely on general practitioners who lack the skills and training to help them.
The warnings were issued in two separate reports – from the charity Beat and the multipartite committee on public administration and constitutional affairs.
They acknowledged that improvements had been made to children's services, but that adult care remained more problematic.
Beat's research has shown that some specialty services have wait times longer than five months.
Andrew Radford, general manager, said: "This research should sound the alarm.
"Eating disorders have one of the highest mortality rates of all mental illnesses yet the chances of a person's recovery are subject to a lottery and lives are in danger."
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"I was so sick that I could not go on anymore"
Hannah, 30, from South London, contracted bulimia in her early twenties. It got so much worse that she made several suicide attempts.
But her only treatment was one hour of group therapy a week – and she had to wait months before starting.
"It was just not enough," she said. "I was so sick that I could not continue, I did not see any future."
After being diagnosed with depression and bulimia, the treatment was still inadequate, Hannah said.
"This was not done significantly – there was no plan of care."
She eventually got help from a charity, but over the next three to four years she developed anorexia.
This time, she went to private treatment because it was available more quickly.
"If I had access to good care in my 20s, I might have been OK.
"The model is flawed.You are asking people to wait for months of treatment while they are already sick and they are passing the door of their GP."
What is the magnitude of the problem?
Estimates suggest that more than a million people suffer from a eating disorder, although activists believe that the real figure could be even higher.
About three quarters of them are women.
There is a range of different conditions.
Anorexia and bulimia – where overeating fits are offset by measures such as forced vomiting or taking laxatives – account for about half of all cases.
Many cases start in adolescence, but the treatment can take years. Most patients therefore need support in adulthood.
Less than half of anorexic and bulimic patients recover fully.
Anorexia has the highest death rate of all mental illnesses.
Affected individuals have a five times higher risk of death, linked to complications such as a weakened immune system and heart problems.
Where does the NHS fail?
General practitioners are often the first point of call for patients.
But the committee warned that they lacked training, and some research suggests that doctors have barely more than "a few hours in medical school".
The committee was told that this had led physicians to simply rely on the body mass index (BMI) as an indicator of problems.
This echoes the research done by Beat, with patients complaining of having trouble getting help.
General practitioners can call on specialized support provided by community mental health teams.
This normally involves some form of speech therapy.
However, information provided under the Freedom of Information Act has revealed a sevenfold increase in the number of people getting help by services.
Wait times ranged from two weeks to five and a half months.
And even when they are referred for help, a significant number of people have to rely on the support of the general health teams because of the lack of specialized staff.
Although both reports looked at services in England, Beat said the rest of the UK had similar, if not worse, problems.
What do we do to tackle problems?
The committee's report followed a review in 2017 by the Parliamentary Services and Health Services Ombudsman.
He highlighted serious failings that contributed to the death of Averil Hart, a 19-year-old – who died after leaving home to go to university – and two other young women.
The committee stated that the findings of its review two years later showed that there had been no progress.
But the NHS England insisted that it was taking action.
The health service has invested in services specifically for under-19s, with a new wait time target expected to come into effect next year.
It requires that 95% of people seeking an eating disorder receive help in the week for urgent cases and within four weeks for non-urgent cases.
Funding for mental health services is also increasing faster than the overall budget.
Some £ 2.3 billion of the additional 20 billion available for the NHS in England by 2020 will go to mental health.
Dr. Helen Stokes-Lampard, of the Royal College of GPs, said more resources were needed to help doctors support patients with eating disorders.
"It's an incredibly complex field and the standard 10-minute rendezvous is just not long enough for us to solve the many complex problems."