I read about this at Cranky Fitness and went on to read the 2 articles she posted.
“Both obesity and thinness are socially contagious,” says study co-author James Fowler, an associate professor of political science at the University of California-San Diego.
Not for the faint of heart:
Scientific Paper: http://content.nejm.org/cgi/content/full/357/4/370
Methods: We evaluated a densely interconnected social network of 12,067 people assessed repeatedly from 1971 to 2003 as part of the Framingham Heart Study. The body-mass index was available for all subjects. We used longitudinal statistical models to examine whether weight gain in one person was associated with weight gain in his or her friends, siblings, spouse, and neighbors
My thinking is this. Have you ever worked with or hung out with a bunch of women? And did you all get pms’d or get your periods at the same time every month? I have. I tend to think this is what’s happening: our bodies tend to tune in to those around us, even if we slap scientific theories on them or not.
And it’s easy to explain why a spouse may be less affected than a friend: A spouse doesn’t listen anyway, so why would his body??