More than 360 children were hospitalised for anorexia or bulimia over the past three years.
According to new figures, there was an increase of 42% between 2016 and 2018.
The Health Service Executive (HSE) says eating disorders, especially anorexia, have the highest mortality rate of all mental illnesses.
Patients with these illnesses tend to have the longest admission in hospitals.
Though eating disorders can happen at all ages, they are most common among the young population.
Ninety people under the age of 16 had inpatient stays in Irish hospitals for anorexia or bulimia in 2016.
According to details released under the Freedom of Information Act, this rose to 145 in 2017.
Last year 132 children had a principal diagnosis of anorexia or bulimia when they were discharged from hospital.
The number of hospital discharges aged 0-16 years by hospital group, 2016-2018 | Source: HSEThere were admissions across the country - but across the three years, 148 children were treated in Dublin's children's hospitals: Crumlin, Temple Street and Tallaght.
Dr Madeleine Ní Dhálaigh is a member of the Irish Medical Organisation's GP committee.
"Those statistics are really quite sobering, because admitting a child or adolescent for inpatient treatment for an eating disorder really is often the last resort.
"Doctors much prefer to treat young people in the home environment, within the family structure.
"If the illness becomes progressively worse they've sometimes no other option".
The HSE says early intervention in eating disorders is key, and outpatient specialist care is the most effective treatment.
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Reporting by Eoghan Murphy
