A Website to Update Your Friends About Your Body Weight
The movement to encourage -- and contain -- social dieting

Why would someone choose to bemoan her difficulties in resisting junk food, accompanied by a photo of herself -- bare-bellied and in a sports bra -- in a Facebook post? I ask only because I've seen it happen. A much better place for a dieter in need of support to turn might be a new site, like Friendship Weight, of that sort that is custom built for these people with both a lot of body dissatisfaction and only a little sensibility about what shouldn't be shared with their entire Facebook network.
The basic premise of Friendship Weight is that users sign up to track their weekly gains and losses (without posting their actual weight), and then invite hand-chosen friends and family members to receive updates on their progress.
In the proper context, harnessing social ties can be an incredibly effective way of reaching a goal. As David Freedman described in The Atlantic magazine last June, socially driven behavior modification is a powerful tool. Freedman reviewed a number of online programs where dieters are teamed up with dieticians, psychologists, and similarly minded peers as a sort of e-support group; but their limitations lay in the high costs (up to $3,000 a year) associated with hiring professional help. Some less expensive apps simply aid in self-motivation/flagellation, or pit users competitively against people who are also trying to lose weight.
The friends you've already got, provided they're good ones, are willing to do a lot of that for free. Or for $9 a month, which is what the site charges for the service of reminding them to send you encouraging messages. This can be particularly helpful once the initial weight is lost and the longer -- by many accounts harder -- period of maintenance begins.
People who already do this sort of thing on Facebook seem to have figured out the power of social motivation for themselves, but are in serious need of an appropriate space in which to utilize it. Rebecca Rosen wrote about an interesting study yesterday where researchers found that, despite high-minded conversation about virtual networks, our best friends in the real world are easily identified by our activities on Facebook. Having things like where you went to school in common with other users was much less predictive of your friendship's strength than shared comments and "likes." What's more, she explains, "The study's authors found that public interactions such as comments and wall posts were just as revealing as private messages."
The study, to me, highlights an area where it's easy to get into trouble. It suggests that we're susceptible to assuming, on some level, that when we share information online, we're in effect doing so only with our best friends. In that space of false intimacy, we forget about the legions of "friends" -- scare quotes intact -- at whom our posts are directed, and who are unlikely to respond or otherwise interact with us, but who are nonetheless there, seeing what we post.
A service that limits your social sphere while appealing to an ethos of online sharing is simple and tasteful solution to that. For those who like the conceit but would rather not pay, you can perhaps do one better by setting up a private group, or email list, or anything else that doesn't subject the rest of us to the kind of information that should be reserved for real friends.