The results of the research by youth charity YMCA, published in a report The Curate Escape, found that because of the pressure they feel to look good, two-thirds of the more than 2,000 11- to 24-years-old surveyed said they often edit photos of themselves before posting them on social media.
Respondents can spend a considerable time on this - 23 per cent said they took more than five minutes editing pictures, with some taking more than an hour.
Common edits include removing blemishes, smoothing skin and whitening teeth. Some (11 per cent) admitted that they edit pictures they post so much that they don't reflect what they normally look like in real life.
This online pressure appears to be affecting the confidence of young people; only 16 per cent said that looking at social media positively affected how confident they felt about the way they look.
The report was commissioned as part of YMCA's Be Real Campaign, which calls for a fightback against unrealistic beauty standards. To that end, social media influencers and advertisers are seen by young people as key to challenging this; 53 per cent said that if celebrities and influencers shared more realistic images of themselves it would encourage others to post content that more accurately reflect what they look like in real life.
In addition, 41 per cent said influencers who promote unhealthy products and behaviours to promote body confidence on their social media channels should be challenged, while 42 per cent said adverts should have to say when pictures have been airbrushed.
Denise Hatton, chief executive of YMCA England & Wales, said: "Social media continues to present a multitude of dangers for young people which they have been left to navigate on their own devices. These dangers are not just limited to the content they see, but also the pressure young people face to emulate them.
"Young people and the general population need to be conscious about the content they are posting online.
"While our research has shown that young people feel compelled to alter their digital selves, they are still in control of the content on their screens. As such, YMCA's Be Real Campaign is encouraging young people to curate their own safe spaces online and follow accounts that make them feel good about themselves."