Obesity can spread from person to person, much like a virus, researchers are reporting today. When a person gains weight, close friends tend to gain weight, too……..people were most likely to become obese when a friend became obese. That increased a person’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 influence than friends….Proximity did not seem to matter: the influence of the friend remained even if the friend was hundreds of miles away…. The same effect seemed to occur for weight loss, the investigators say. But since most people were gaining, not losing, over the 32 years of the study, the result was an obesity epidemic. 
There was no effect when a neighbor gained or lost weight, however, and family members had less influence than friends….Proximity did not seem to matter: the influence of the friend remained even if the friend was hundreds of miles away…. The same effect seemed to occur for weight loss, the investigators say. But since most people were gaining, not losing, over the 32 years of the study, the result was an obesity epidemic. 
