Parents worry all the time about whether their kids are hanging out with the right sort of peers. They understand friends can have a big impact on how they grow up; and often, because many youth congregate more on Facebook than anywhere else, they check in on their children’s relationship on the social networking site. What if Facebook itself was a bad influence—even for parents? According to a new study, it might well be. “People who use Facebook more tend to have a higher body-mass index (BMI), increased binge eating, carry more credit card debt and have lower credit scores,” says Andrew Stephen, an associate professor at the University of Pittsburgh and one of the authors of a new study. It’s not that Facebook or other social networks are exerting overt peer pressure: Facebook’s head honcho Mark Zuckerberg isn’t encouraging users to buy rocky road ice cream on their credit cards with the tag “C’mon, everybody’s doing it.” Part of the problem, researchers say, is that using Facebook makes users feel good about themselves, which in turn lowers resistance to keep some of their impulses in check. “Simply browsing Facebook makes people feel better about themselves and momentarily enhances their self-esteem,” says Keith Wilcox, an associate professor at Columbia University. “It’s that enhanced self-esteem that ultimately lowers your self-control.” (Today)