Yeah, in the USAF the fattest dudes I have seen are either in cyber warfare, COMSEC, or Command Post.  Depending on the base and manning those jobs can be pretty shit (long sedentary hours).  At least the other shit jobs in the USAF (security forces or aircraft maintenance) are active throughout the day and have our own sub-cultures.  Those guys have to have a boring/shitty job, sit around all day, and deal with Big Blue Air Force.  I shudder to think what my life would have been like if I hadn't gone maintenance.