A television ad for cosmetic surgery featuring people admiring themselves after undergoing nose, teeth and breast procedures must not screen again before 9pm to minimise the risk of children seeing it.
The ad for The Hospital Group Healthcare was seen by 35 complainants between 6.45pm and 10.45pm on various television channels and began with a woman, who had a long nose, scowling at herself in a mirror.
A man was shown giving a business presentation while looking uncomfortable and covering his mouth with his hand before a close-up showed he had crooked teeth, and a woman was shown walking along a street with her arms crossed tightly across her chest, wearing a baggy jumper and looking unhappy.
A voiceover said: "If you're unhappy with your appearance you could change it. If it affects your confidence you could overcome it. If it makes you feel self-conscious, you could take control with cosmetic surgery or dentistry from The Hospital Group.
"So if other self-improvement methods haven't worked, talk to the experts. And just like thousands of others, start seeing the new you."
The Advertising Standards Authority (ASA) said most of the 35 complainants believed that the ad was irresponsible for trivialising cosmetic surgery and implying that happiness could be achieved through cosmetic surgery.
Most of the complainants also challenged whether the ad was scheduled irresponsibly when children might see it, because they believed it could have a negative impact on body image.
The Hospital Group said the ad showed scenarios that were relevant in everyday life and drew on patient feedback that said a lack of self-confidence was a significant factor in their decision to undergo surgery.
It said it only targeted adult-viewing programmes when booking advertising spots, and as its licence was limited to procedures on adults only there was therefore no financial gain in targeting those aged under 18.
The ASA found that while some adult viewers might find the ad distasteful, it did not trivialise cosmetic surgery and was therefore not generally irresponsible.
But it said it was concerned that children, and in particular young teenagers, were likely to interpret the ad differently to adult viewers, noting that the depictions of the characters' sudden physical transformations were accompanied by an instant and dramatic change in their emotional well-being.
The ASA said: "We considered it likely that many young teenagers would identify with such negative feelings about their physical appearance.
"We considered the ad's scenarios were likely to reinforce harmful feelings that those who did not have a 'perfect' physical appearance were unattractive and should be self-conscious about their looks, should aspire to a particular ideal of beauty, and that they should take action to change their physical appearance in order to meet that ideal.
"We therefore considered that a scheduling restriction should have been in place to minimise the risk of children, particularly young teenagers, seeing the ad. We concluded the ad should have been given a 9pm timing restriction."