A Heavy Influence

In a fascinating study reported today, researchers found that our friends have a very big influence on weight--in other words, obesity can be contagious. According to the International Herald Tribune, researchers who followed residents of Framingham, Massachusetts for decades made a surprising discovery:

[P]eople were most likely to become obese when a friend became obese. That increased one's chances of becoming obese by 57 percent. There was no effect when a neighbor gained or lost weight, however, and family members had less of an influence than friends. It did not even matter if the friend was hundreds of miles away - the influence remained. And the greatest influence of all was between mutual close friends. There, if one became obese, the other had a 171 percent increased chance of becoming obese too.

It's fascinating to me that obesity can spread through social networks. Ever since I read Bowling Alone, I've been interested in the benefits of social connections and social capital. This study suggests, however, that interconnectedness can have a downside. In the coming years, the challenge for our society will be to see if, without stigmatizing people who are overweight or obese, we can channel the power of friendships into making ourselves healthier.