From Friday patients will be able to claim 40 sessions of psychological treatment for an eating disorder in a 12 month period, and up to 20 sessions with a dietitian in the same period.

This would include treatment for people with anorexia, bulimia and issues around binge-eating.

One-in-20 Australians are estimated to live with an eating disorder with more than 70 per cent of people with eating disorders avoiding treatment.

Kim Coffey has three daughters who have experienced an eating disorder and treatment costs had been prohibitive.

"We have spent so much money on psychologists, nutritionists and other health professionals just trying to get our daughters well," Ms Coffey said.

"Family holidays and other luxuries have fallen by the wayside. We at least had the option to afford treatment, where many just don't."

InsideOut Institute for Eating Disorders director Sarah Maguire told AAP the changes were "very big news" for people with eating disorders and their families.

Dr Maguire said the new amount of sessions was the minimum treatment recommended for patients, who only had access to 15 psychology sessions before.

"Eating disorders are mental illnesses, they originate in the mind," Dr Maguire said.

"Their main action of expression is your body and your relationship with food."

Dr Maguire hoped to see a drop in the rate of people avoiding treatment, saying early intervention could result in a full recovery in up to 80 per cent of cases.

Butterfly Foundation chief executive Kevin Barrow this came at a critical time for people with serious mental illness and was a much needed reform.

"We know that, with the right intervention and support, full recovery is possible," Mr Barrow said.

Patients would have to be assessed to have an eating disorder by a GP.

The changes will also allow people to get a rebate to develop an eating disorder plan, a formal specialist review by a consultant and regular GP reviews of their progress for the treatment plan.

The plan would expire and need to be reviewed at the end of each 12 month period.

While the Australian New Zealand Academy of Eating Disorders welcomed the changes, it cautioned patients to only seek out clinicians with experience in treating eating disorders.

President Kim Hurst said proper treatment required a well-coordinated team of mental health, dietary and medical professional experts.

Australian Associated Press