Staying in shape

Alright, so I've got an internship lined up at B4. I'm excited for the free food that will be constantly flowing, although concerned as to how I'm not going to gain 50 pounds while eating it all. Is it possible to stay in shape eating out all the time? Any tips? At my current job, I always pack my own lunch (budget reasons, mostly) and work out a few times a week. Not sure how my body will transition to butter-laden restaurant food. How do you stay in shape? Any tips? Or should I just pack on the hibernation pounds, since it's not like anyone from the outside will see me anyway.