Junk food advertising could disappear from Australian children's entertainment platforms in a bid to stamp out childhood obesity.

Marketing of unhealthy foods would be prohibited from 6am to 9.30pm on TV and radio broadcasts, while ads on social media and online sites would be banned outright, under a proposed bill to be introduced to parliament on Monday by independent MP Sophie Scamps.

However, print or outdoor advertisements, marketing as part of sports sponsorships, and content shared by food and beverage companies on their own channels would not be impacted.

"Our children are exposed to over 800 junk food ads on TV alone every year, and there is a direct link between those ads and childhood obesity," Dr Scamps said.

Obesity is estimated to cost the health system $11.8 billion every year with a quarter of children on the path to chronic disease due to being overweight.

The former general practitioner and athlete argued current restrictions were not strong enough and self-regulation was just not working.

"If we continue to stand by while children are deluged by junk food advertising on social media and on TV, then we are failing them," she said.

Broadcasters, service providers and food companies could face hefty fines if they fail to adhere to the proposed guidelines.

The bill has the support from fellow MP and former pediatrician Monique Ryan as well as a host of health and medical associations.

Regulating unhealthy food marketing is a critical first step on the road to safeguarding children's futures, Food for Health Alliance executive manager Jane Martin said.

"Our children deserve a healthier future, free from the constant bombardment of junk food marketing."

Professor Nitin Kapur, from the Royal College of Physicians, urged the government to intervene for the sake of our children's health.

"Children are exposed to predatory marketing of junk food and sugary drink across multiple mediums," Prof Kapur said.

Dr Scamps has been heartened by conversations with the government and believes there is an appetite for change.

About 40 countries have or are planning to regulate junk food advertising including the UK, South Korea, Norway and Chile.