Complaints over an advert showing two girls eating Dairylea cheese triangles upside down has led to it being banned for encouraging 'unsafe behaviour.'
The authority stepped in after reports of one person saying their three-year-old relative had tried to copy them.
People had reported the video, seen on ITV Hub, All 4 and My 5 in August, as they claimed other kids could copy them and end up choking.
There were 14 viewers who felt that the girls hanging upside down from a football goal before one opened the cheese snack and ate it, condoned or encouraged behaviour that could be dangerous if children copied it.
Dairylea owner Mondelez UK said the ad's purpose was to show parents allowing their children more freedom and the video included two supervising parents in the background.
Mondelez referred to a study that they said supported their view that a person's ability to swallow was not affected by the position they ate in, including when eating upside down.
Based on the research, and because Dairylea was a soft food, they considered there was a very low risk of choking when eating upside down.
The ad had also been given an "ex-kids" scheduling restriction, but Mondelez said they were no longer running it and would remove references to eating upside down if they used it in future.
The Advertising Standards Authority (ASA) said it sought advice from the Child Accident Prevention Trust, whose view was that the scenario depicted in the ad represented a situation where there was potentially a high risk of choking.
The ASA also noted that one complainant had reported that their three-year-old relative, after seeing the advert, ate their food whilst hanging upside down.
The ASA said: "We therefore considered that eating whilst upside down was an unsafe practice and one which could be dangerous for children to emulate.
"We therefore concluded that a scheduling restriction was not sufficient to reduce the risk of harm and that the ad breached the Code."
The ASA ruled that the ad must not appear again, adding: "We told Mondelez UK to ensure their advertising did not condone or encourage unsafe practices."
A Mondelez spokesman said: "We recognise and will abide by the ASA's decision but we are disappointed by the ruling.
"We carefully consulted with Clearcast to pre-approve the content of this video on demand advert prior to airing.
"It was aimed at adults (parents) rather than young children and was deliberately scheduled away from programming likely to appeal to children under 16. As such, we believe it was unlikely to encourage 'copycat' behaviour by young children.
"We remain committed to responsible advertising and work with a range of partners to make sure our marketing meets and complies with all relevant UK regulations."
