Beware: using Facebook can make you eat more and get into debt - but still feel really pleased with yourself, researchers say.
Users that feel strong ties to their friends tend to feel high self-esteem while actually on the site, and a loss of self-control afterwards, says the University of Pittsburgh and Columbia Business School team.
And the more time these users spend on the site, the greater their body-mass index - and the higher their levels of credit-card debt.
"To our knowledge, this is the first research to show that using online social networks can affect self-control," says Andrew Stephen of the University of Pittsburgh.
"We have demonstrated that using today’s most popular social network, Facebook, may have a detrimental affect on people’s self-control."
The team worked with more than 1,000 US Facebook users, who completed surveys about how closely they’re connected to friends on on the site. And, they found, participants with weak ties to Facebook friends didn't feel any more self-esteem - but those with strong ties to their friends did.
And this high self-esteem seems to be linked with poor self-control. When given the choice between a cookie and a granola bar, people who had recently browsed Facebook were more likely to pick the cookie - and were also more likely to give up when set a puzzle.
And a survey covering height and weight, the number of credit cards owned and the number of offline friends also showed the Facebook users to be particularly weak-willed.
"The results suggest that greater social network use is associated with a higher body-mass index, increased binge eating, a lower credit score, and higher levels of credit-card debt for individuals with strong ties to their social network," the researchers write.