Takes a lot of humans to get the meal to the table. More than
  just the cooks. Basic humanistic respect says a moment of thanks
  isn't too much to ask. Change the word prayer to "gratitude" if
  you like. It's just a word. well its easy enough. You don't have
  to close your eyes or anything. Just imagine for a moment the
  Industry involved - the truckers, the ships, the planes, the
  migrant workers, a mental map of all the countries and where you
  think each part of the food on your plate came from, the spices
  used... and how lucky you are to have been born in the
  Timestream at this particular point in history, in the body that
  you're in, in the place that you're living in and that you are
  breathing and have food in front of you.

  I'm agnostic (100% - don't know either way) - but gratitude only
  takes a second and nobody has to know. think about it: if it
  really didn't mean anything and you _want_ to do it, then do it.
  If it's JUST A WORD, why restrain yourself? Who are you trying
  to impress? It's just a word. Athough to be fair, I don't use
  the word God much even to myself for a similar reason: the
  societal baggage attached. So I just "Thank You" in general,
  specific to the people, unspecific to whatever else I don't know
  about. No religion required. Just gratitude.