Food catering is minimal in CC coaches.
I have traveled from Balasore to Howrah, and only got cold samosa and Sweet curd (Meetha Dahi) for eating. No PC guy was selling water bottles and not even once Tea/coffee came. If boarding from Balasore onwards in CC, then better purchase good amount of chips/biscuits/cold drinks because you really will be needing good snacks to enjoy the excellent speed and outside views from the windows.