My brother sent me an article claiming scientific evidence for the idea that obesity is a socially-contagious disease.
The answer, the researchers report, was that people 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.
The same effect seemed to occur for weight loss, the investigators say, but since most people were gaining, not losing, over the 32 years, the result was an obesity epidemic.
Dr. Nicholas Christakis, a physician and professor of medical sociology at Harvard Medical School and a principal investigator in the new study, says one explanation is that friends affect each others' perception of fatness. When a close friend becomes obese, obesity may not look so bad.
"You change your idea of what is an acceptable body type by looking at the people around you," Christakis said.
I doubt that perception is the major influencer of weight gain or loss... from personal experience, fat friends want to go out and eat crap all the time, whereas skinny friends want to eat healthy and have fun in physically active ways. Either way, there's on doubt that the friends you pick have a large influence on you -- food for thought!