Children and young people across the state are being exposed to at least 25 advertisements for unhealthy foods and drinks each day, a new Cancer Council Victoria study has shown.

Before the pandemic, more than 60 per cent of food and drink advertisements on Melbourne's public transport and near schools was spruiking unhealthy options and treats.

Mr Chatfield, a VicHealth ambassador, has added his voice to Cancer Council Victoria's new Food Fight campaign aiming to curb the enticements and raise awareness of processed food's impact on young people's health.

The 21-year-old, who hails from Koroit Football Club, has this year stepped up to Footscray's Victorian Football League list and has been named as a top-up AFL player for Western Bulldogs under new COVID-19 rules.

He said football offered him a good platform to be a role model and help make a positive, healthy difference.

"I'd do anything to help promote enjoying a healthy life and positive relationships with food, especially being part of a football club," Mr Chatfield said.

"I want to help in making sure children have a positive future with eating and what they're putting in their body. Building healthy relationships with food is a must and that includes wherever you are socially connected, especially after school when there is the urge to get junk food with your mates."

Children who were exposed to high levels of food and drink advertising were more than twice as likely to have tried a new food and drink product, Cancer Council Victoria found.

Mr Chatfield said sporting clubs were a great place to build social connections and a great start to improving your lifestyle. He also wanted to be a healthy role model for his younger siblings.

Cancer Council Victoria's obesity program executive manager Jane Martin said some people might find the Food Fight campaign confronting but children's health was at stake. Global research has shown fast food advertising was effective in influencing children and impacting their diets, putting them at long-term risk of serious disease and up to 13 preventable cancers.

Ms Martin pointed to transport bans on unhealthy food advertising in London, Amsterdam, New York and Canberra for successful drops in kilojoule-laden food and drink purchases. She said there was no reason why Victoria should not be next.

"Our children deserve to grow up in environments that support and promote good health and well-being and governments have a role to play," Ms Martin said.