A support group that helps parents of children with eating disorders believes there is a record number of young people being treated at Starship Hospital in Auckland.
Four adolescents are currently being treated at the hospital.
A lack of inpatient services in Auckland means 11 people have had to be sent to Australia for treatment since December 2006.
The Eating Disorders Association says Starship is not set up to cope with severe eating disorders.
Another group, the Eating Difficulties Education Network, says current funding is not meeting demand.
The northern regional director of mental health and addiction services, Ian McKenzie, acknowledges there is a gap in services, but says there is a coherent plan among the district health boards.