Hospital admissions for eating disorders rose by 16% in England from 2011 to 2012, official figures show.
Preliminary data from the Health and Social Care Information Centre (HSCIC) show 2,290 admissions in the 12 months to June 2012.
Three quarters were related to anorexia nervosa, and children and young people account for most admissions.
Eating disorder experts have said that the figures are "just the tip of the iceberg".
It is estimated that, across the whole of the UK, about 1.6 million people are affected by an eating disorder.
The figures reflect for the number of admissions, rather than patients, and the HSCIC says some may have been admitted to hospital more than once.
One in every 10 of the admissions was a 15-year-old girl.
And women made up 91% of admissions, up from 88% in 2010-11.
A quarter of those admitted were discharged on the same day, while 5% spent at least six months as in-patients.
The region with the highest number of eating disorder admissions by population size was the north east - where there were 5.8 per 100,000 (150 admissions).
Tim Straughan, chief executive of the HSCIC, said: "It might be assumed that a person suffering with an eating disorder is cared for in the community through primary services rather than in hospital, with activity in secondary care only part of a bigger picture.
"However, our figures do suggest that hospitals in England are admitting a greater number of eating disorder cases than in previous years.
"The data points to a relatively small but nevertheless significant rise in child admissions for the treatment of an eating disorder."
A spokeswoman for the eating disorders charity Beat said that, since only those who were most seriously ill were admitted to hospital, these figures were "just the tip of the iceberg".
She said earlier treatment and more community-based care was needed.
A Department of Health spokesman said: "We take the issue of eating disorders, especially among young people, extremely seriously.
"Early intervention is essential for those with eating disorders and there is clear guidance for GPs when choosing the most appropriate treatments for individuals."