Surprise surprise, Facebook is making people feel bad about themselves.

According to a new study from University of Auckland, women in their mid-30s to mid-40s are the most likely to feel dissatisfied with the way they look after using Facebook, a new University of Auckland study shows.

The research, by doctoral candidate Samantha Stronge and published in the journal Sex Roles, is the first study of its type in New Zealand.

Study participants were drawn from the New Zealand Attitudes and Values study database run by Associate Professor in the School of Psychology Chris Sibley.

The study group of more than 11,000 people was made up of 62.5%women and 37.5% men aged 18-years-plus with a mean age of 49.23 years. They included both Facebook users and non-users.

Among women, 69% had a Facebook profile and 58% had used it in the past week. Overall, women used Facebook more often than men.

The study showed women Facebook users in their mid-30s to mid-40s had the lowest level of body satisfaction of any group, with women aged 38 least happy with the way they looked of any age group.

For women Facebook-users, body satisfaction levels begin to fall at around 30 years but did start rising again as they got older – at around 50. Women who didn't use Facebook had higher body satisfaction overall.

“We know from previous studies that media in general can make women feel bad about the way they look,” Stronge says. “What we see in this study is that those findings are replicated for social media users and in this case, women who use Facebook on a fairly regular basis.

In general, men reported higher levels of body satisfaction than women but men who used Facebook still reported lower levels of body satisfaction than their non-Facebook-using counterparts.

“Similar to women, men who use Facebook were less likely to feel satisfied with the way they looked so that seems to suggest that the effect of idealised versions of femininity and masculinity in social media is similar for men and women,” Stronge says.

The fact younger women showed higher levels of body satisfaction than older women was an interesting result from the study.

“It may be that for younger women, those around the 18-years-old age group, Facebook use is simply a normative practice and therefore not related to body satisfaction but more work does need to be done in this area.