Social networks may increase individual tendencies toward obesity.
Another cutting edge study from Framingham suggests that that "obesity appears to spread from one person to another like a virus or a fad, researchers reported...in a first-of-its-kind study that helps explain -- and could help fight -- one of the nation's biggest public health problems." that "social networks play a surprisingly powerful role in determining an individual's chances of gaining weight." For example, when one spouse in the study "became obese, the other was 37-percent more likely to do so in the next two to four years, compared with other couples."
[Volume 357:370-379 July 26, 2007 Number 4]