Junk food advertising would be banned from television and radio between 6am and 9.30pm in a bid to curb child obesity rates under legislation to be debated by Parliament.
The obesity busting bill was introduced on Monday by Teal MP Sophie Scamps.
"Our children are being preyed upon every time they turn on the TV, listen to the radio, or go online, by companies that seek to profit at the expense of our children's health," Scamps said.
She said one in four children were overweight and that obesity was costing the health system $11.8b every year.
She said part of the problem was that children were exposed to more than 800 advertisements for junk food every year on television alone.
"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.
She also claimed "particularly insidious" online algorithms targeted children with advertisements for junk food. She is seeking to have a complete ban on such ads.
Scamps wants broadcasters as well as food companies to be hit with big fines if they breach the proposed legislation.
The bill was backed by Monique Ryan who claimed it was necessary because children's minds were more susceptible to the persuasion tactics and can't tell the difference between ads and facts in junk food marketing.