Obesity Is 'Socially Contagious'

My interest here is the mimetic one. I heard this on Radio 4 this morning. "If a person you consider a friend becomes obese, the researchers found, your own chances of becoming obese go up 57 percent. Among mutual friends, the effect is even stronger, with chances increasing 171 percent." One of the presenters asked a pertinent and disarmingly simple question: 'why don't you get thinner among skinny friends?' This is partly answered by this explanation: "Consciously or unconsciously, people look to others when they are deciding how much to eat, how much to exercise and how much weight is too much." I say 'partly' because we need to say also that because eating is generally pleasurable and sometimes social, and because exercise is hard work and so there is a tendency to avoid it, the mimetic drives are stronger in directions that lead to overweight. However; "It's important to remember," Fowler said, "that we've not only shown that obesity is contagious but that thinness is contagious." But, if I'm right, thinness can be contagious but more factors need to be in place for it to be so.
ScienceDaily: Obesity Is 'Socially Contagious':