Australia Day is the country's peak day for youth drunkenness and assaults, according to a new study sponsored by Vic Health.

The Turning Point Alcohol and Drug Centre studied 10 years of police, ambulance and hospital data on public holidays.

The findings showed ambulance attendances for intoxicated people under 25 almost doubled on Australia Day.

Vic Health's Brian Vanenberg says there is also a two-fold increase in injuries due to assaults.

"We've found that there's a spike in alcohol-related problems on days like Australia Day, and not surprisingly New Year's Eve and Anzac Day as well," he said.

"We think that the research really highlights that it's time for Australia to really change the way we drink."

Assaults and acute intoxication in those over 25 years old peak on New Year's Eve.