The chart on the right is excerpted from the Wall Street Journal. It shows which occupations have the lowest obesity rates, and most of it makes sense. There are folks who do a lot of physical labor (janitors, 
maids, cooks, etc.). There are health professionals who are probably hyper-aware of the risks of obesity. There are athletes and actors who have to stay in shape as part of their jobs.
And then, at the very bottom, there are economists, scientists, and psychologists. What’s up with that? Why would these folks be unusually slender? I can’t even come up with a plausible hypothesis, aside from the possibility that these professions attract rabid obsessives who are so devoted to their jobs that they don’t care about food. Aside from that, I got nothing. Put your best guess in comments.