The stress of COVID-19 has led to a surge in eating disorders in Victoria, with one support service experiencing a 300 per cent increase in demand through the pandemic.

Eating Disorders Victoria saw the 300 per cent spike in calls to its helpline from 2020 to 2021.

The organisation's nurses also spoke to more than 900 patients in 2021 alone.

Peer worker Gemma De Leo said the pandemic has meant more people are being diagnosed with eating disorders. People in recovery have had their symptoms worsen and some who recovered have relapsed.

"We know that eating disorders are not about wanting to be thin - they're not about vanity," Ms De Leo said.

"It's about a coping strategy and when people feel like their life is out of control and things are slipping away, we turn to that coping mechanism that might be an eating disorder."

Mental Health Minister James Merlino said there was a 53 per cent increase in people with eating disorders presenting to the state's emergency departments at the peak of the pandemic.

He announced on Wednesday $20 million from the state budget would go towards supporting nearly 3200 Victorians with an eating disorder every year, which is about 1100 more people than were treated last year.

However, Eating Disorders Victoria said it was estimated about one million Australians struggle with some sort of eating disorder, equating to about 360,000 people in Victoria.

"The thing that we're really focusing on is that only a quarter of those people are accessing services," Ms De Leo said.

"Our main goal is making sure that everyone with an eating disorder has [the] ability to access treatment."

Eating disorders have the highest mortality rate of any psychiatric illness and people with one are 32 times more likely to have anxiety or depression.

Victoria's royal commission into the mental health system found there was an 11 per cent annual increase in eating disorders over the last decade before the pandemic.

The Andrews government's funding will also go towards creating another 15 mental health beds in Melbourne for patients who have eating disorders.