The Hard Facts: Your Friends Might Not Be Making You Fat

It’s Research Wednesday! Where I share the latest, or most fascinating, in the science of friendship.

“Over the past few years, a series of highly publicized studies by two researchers have concluded that behaviors like [overeating, smoking and drug use]  can be literally contagious — passed from person to person. … But now those surprising conclusions have drawn heated criticism from other scientists who claim that the studies’ methodology was flawed and the original data completely inadequate to estimate the role that contagion might play in the spread of these behaviors.” (“Catching Obesity From Friends Might Not Be So Easy” New York Times, 8/9/2011)

You know how one day scientists will say something is unhealthy–red wine, perhaps, or chocolate, or cheese–and the next day they’ll be telling you to get at least three servings a day? How one day fat was the devil, until it wasn’t, and instead we should cut the carbs. And then carbs got added back, but only the unprocessed ones, and sugar became the target? That’s what’s becoming of the latest friend research.

First, behavior was contagious. The activities of our friends was the most important thing when it came to our own healthy behavior. I wrote on this blog about research that said unemployment could be “caught” between buddies. But the same held true, supposedly, for smoking, drinking, levels of happiness, exhaustion, and weight. The theory as to how this contagion works is interesting and, in my opinion, convincing. Here, the author is referencing weight contagion: “A person’s idea of an acceptable weight, or an acceptable portion size, changes when he sees how big his friends are or how much they eat.”

This was the claim of the researchers, and I buy it. My ideas of what is acceptable is directly influenced by my friends, if I’m being honest. Not just any friends but, for me, it’s the friends I see regularly. They influence what I deem “normal” and then, subconsciously or not, I adapt to fit that mold.

But “not so fast!” say the other scientists. (They really love challenging each other’s research don’t they? Tough crowd.) Apparently, according to the haters, it’s “impossible to separate homophily [the tendency to choose friends like oneself] from contagion.” So, basically, there’s no way of knowing if people are “catching” behaviors, or simply flocking to those who behave as they do. Birds of a feather and all that…

The end result: Smokers are friends with smokers, happy people hang with other happy people, and when your friends eat too much, you probably do too. The reasons why this is the case? Still up for debate.

Oh, the scientists. They’re just never satisfied.

Have you ever noticed that your behaviors are similar to the friends you associate with? If so, do you get the sense that you chose your pals (however subconsciously) because of these similarities? Or have you grown more similar–passing behaviors between you like the flu–as your relationship has progressed?