Hospital admissions for patients with eating disorders jumped by 33% during the pandemic.
Official NHS data reveals 4,576 needed hospital treatment in England for conditions like anorexia and bulimia during the 12 months ending in April.
This is a sharp rise of more than 1,100 from 3,449 in 2019/20.
Tom Quinn, of the eating disorder Charity Beat, said: "These figures are worrying and unfortunately the rise is not unexpected, as over the course of the pandemic we saw demand to helpline services increase by 302%.
"Those affected by eating disorders have had to cope with extreme changes to daily routine, increased isolation and lack of access to support networks."
Mr Quinn believes more people ended up in hospital as they had been unable "to access treatment promptly in community settings."
He said: "Treating people quickly doesn’t only bring about better results for the individual but it also makes the money go further.
"It means more people can be seen early in the development of their eating disorder and less people need crisis services or hospital admission.
"The Government recently pledged an additional £40million to children and young people’s mental health services.
"It is crucial a fair share reaches eating disorder services."
Claire Murdoch, NHS England mental health director, told how staff had responded rapidly to support the rising number of people in need.
She said: "Anyone who needs support should come forward. The NHS is here for you."
Claire Murdoch, NHS England’s Mental Health Director, said: "The last year has taken its toll on the country’s mental health and our staff have responded rapidly to support the increasing numbers of people coming forward.
"Children and young people’s community eating disorder services are in place in every part of the country, treating more children and young people than ever before, with additional capacity being made available for those who need care, while adult services have been working hard to minimise disruptions in care by using virtual platforms for appointments and anyone who needs support should come forward – the NHS is here for you."
