Yesterday a study was published in the New England Journal of Medicine all about how our social networks seem to influence whether we become obese - or lose weight (free full text if you want it). It was an opportunistic study that used the data from the 12,000 people in the long term Framingham Heart Study in Massachusetts. For this particular analysis, they used 32 years worth of data.
By analyzing the BMIs of friends and family over time (who were given as emergeny or information contacts in the original questionnaires), the team found that people who gain weight seem to drag their friends with them.
My first reaction was, well OF COURSE that makes sense. Obesity, while containing a large genetic quotient, tends to be about lifestyle choices. Lifestyle choices tend to be shared by social circles; social circles tend to be in the same geographic or socio-economic neighborhood, which is also a predictor of obesity...and badda bing badda boom! A bunch of fat friends.
My interest was actually piqued upon reading the New York Times this morning, and finding they had a discussion board about the story they ran on the study yesterday.
The discussion board is TERRIFYING. I’ve read most of the comments; I COULD NOT PULL MY EYES AWAY. There certainly are a lot of people in America who are angry about obesity - either because they themselves feel attacked, stigmatized and blamed for their weight OR because they just want obese people to quit eating Ho-Hos and go for a walk already. In fact, many of commenters criticized the study because it was just so OBVIOUS, that it couldn’t possibly be, like a REAL cause of obesity or whatever. There were few level heads to go around.
A large portion of writers were angry about this study because they found it to be, yet again, more blame, another reason to steer clear of fat people and rightfully mock them. One person said they felt like they might wake up tomorrow and have less friends. Others attacked the study as pseudo-science, anecdotal bullshit, STOOPID (sic). One man even demanded that the lead author pay back the money he received to conduct the study.
Most seemed particularly angered by the use of the word “contagious”. And I agree, it might not have been the most prudent choice of words from the NYTimes. And suggesting you ditch your fat friends is, urm, kind of mean. But what is shocking about the scaling up smaller social experiments on eating habits to a longitudinal, epidemiological approach?
1) This study from 2006 found that people eat more when they are in the company of their friends, not strangers or alone.
2) Or take this 1994 study, which found that family dinners are larger than solitary meals, and friend-social dinners are larger and of longer duration than solitary meals; and longer duration meals = more food intake.
3) Meals size increases by a power function to the number of co-eaters and we can eat up to 75% more with lots of friends or family compared to when we are alone.
It’s not to say that fat is contagious, but social forces are obviously HUGELY powerful determinates of how much we eat, when and where. And just as important a part of understanding the rise in obesity as genetics, food availability, portion sizes, the shift to more sedentary jobs, cars and suburbs. And lambasting a study because it made you FEEL BAD, is not appropriate criticism.