Friends Can Make You Fat! - or Fit!

In my work as a behavioral change consultant I have the chance to talk with helping professionals all over the world. One thing is no secret to them or to me, the power of social networks on individual behavior. For anyone— a kid getting into trouble to an adult indulging in unhealthful behaviors— it’s pretty true. Change is hard, but if you change your friends, you can change your life.

For decades, sociologists and philosophers have suspected that behaviors can be “contagious.” Now, scientists are on to it. How does that work? And how wide is the sphere of influence? A recent New York Times magazine article by Clive Thompson describes that your friends—and even your friends’ friends and beyond—can make you quit smoking, eat too much or even get happy.

So, we’re doing all we can to eat well and train hard, to live a healthful life. What happens if people we know start to gain weight or take up smoking? Surely that can’t impact me? Thompson summarizes some research and says, oh yes it can! When one person in a social network gains weight, it turns out that his or her friends are 57 percent more likely to gain weight too. And the link doesn’t stop there. A person can be roughly 20 percent more likely to gain weight if the friend of a friend gains weight…even if the connecting friend didn’t gain a single pound. And, guess what … a person’s risk of gaining weight went up by about 10 percent even if a friend of a friend of a friend gained weight. The same patterns appear for smoking, drinking and even unhappiness.

Oh my! So, here I am minding my own business in Maryland, and the text I get from my friend who’s pushing herself away from the sports bar in downtown Los Angeles, telling me how much her friends are eating and drinking and sleep-depriving … even those people can affect me and my decisions?

How does this happen? “People are connected, and so their health is connected,” the author explains. One theory behind this is that we pick up subconscious social signals from others, signal that serve as normative cues. So, 3000 thousand miles away, the indulgences of people I have never and will never meet are making it okay for me to indulge a little myself, to be a tad less healthful—or worse. Wow. I guess impulse checks come in handy.

Thompson also describes another significant finding for those of us that want to increase our fitness and well-being: if you want to be happy, it’s important to have lots of friends. His research shows that the happiest people have the most connections, even if all the relationships aren’t necessarily deep ones. It comes from having daily exposure to many small moments of contagious happiness. When we frequently see other people smile, our spirits are repeatedly affected by our mirroring of their emotional state. How perfect for us then, as swimmers! Regularly going to practices and meets and swimming with others when we travel out of town, we can make new connections every day with people who are doing healthful things.

What if, though, we expand our network of casual acquaintances only to unwittingly include a few negative sourpusses? That’s okay, according to Thompson. The gamble of increased sociability pays off, and for a surprising reason: happiness is more contagious than unhappiness. The study indicates that each additional happy friend boosts your good cheer by 9 percent, while each additional unhappy friend drags you down by only 7 percent. So, no matter what, adding more links to your social network should add to your net happiness level.

I guess we better be a bit careful who we communicate with, and who communicates with them, especially as connections and influences jump miles and links. The power of social networking technologies is immense, toward and away from our own health. But, to go ahead anyway and take the risk, keep swimming and keep expanding our swimming social network. One sure way to do this, and we can even add it to our list of New Year’s resolutions, is to keep hanging at the pool and keep hanging with others who hang with others who are working to get fit.

To read more:

• Clive Thompson—“Are your friends making you fat?”--New York Times, 9/10/09
• Google “The Framingham Heart Study”
• Forthcoming: “Connected” by Nicholas Christakis and James Fowler