My ex-roommate Bryan, ever the sleuth, discovered an amazing animation in Figure 2 of the paper, which shows graphically how the obese people conglomerate and become bigger together as little yellow circles. Yellow, no doubt, to allude to bulging lipid micelles.
A hilarious article or blog (? I can't remember which...) on the NYTimes pondered if over-weight people would lose friends as a result of this study. I think they forgot that most of the people in the study were not obese to begin with!
The full text of the article (and the animation!) are available here.