When I worked as ground staff if there was more than one person at the gate I would go down and help the crew during the beging of the turn roung so that the could have 5 mins to sit down and eat something. We would try to get thing organised so that boarding didn't take as long. Some of our crews were doing 6 sector days so we always tried to do this on at least 1 turnround.
I have worked for several airlines and at each on the captain could delay the flight so the crew could eat (although they were always reluctant to do this!!)