More than 240 people had inpatient admissions in acute hospitals due to eating disorders last year.
The vast majority related to anorexia with children the most affected group.
The HSE says 189,000 Irish people will experience an eating disorder at some point in their lives.
Research shows this is rising particularly among adolescents.
The HSE says anorexia has the highest death rate of all mental health disorders.
Last year, 241 people had an inpatient admission in an acute hospital due to an eating disorder with 88% being female.
Of these admissions, 189 were down to anorexia, eight were due to bulimia and the remaining 44 were other eating disorders.
133 of the admissions related to children.
Harriet Parsons from Bodywhys, the Eating Disorders Association of Ireland, says anorexia is a big problem among children.
"Up until a couple of years ago the average age of onset would have been about 15-24 years old and that age has come down now so the average age of onset for anorexia is 13-18 and the same for bulimia.
"So what that means is that more people are developing eating disorders and they are becoming younger at the point where they develop the eating disorder so that is really worrying."
Ms Parsons said that the new figures on hospital admissions are very concerning.
"The reason they would be admitted into hospital would be that their restrictive eating would have caused them physically to deteriorate to the point where their health and their live is really at risk."
The HSE says it aims to establish 16 community-based eating disorder teams across the country to deal with the problem.
If you or someone you know is struggling with an eating disorder, contact Bodywhys on 01 2107906 or firstname.lastname@example.org.