I actually find the the post-lunch coma to be really distracting and wonder if companies could benefit trying to feed their employees twice a day with a light late breakfast and then later light lunch.
Pivotal labs does this by offering everyone free catered breakfast at the start of the day. As I understand it, the motivation was to synchronize everyone's lunch hunger so half of a pair-programming team wasn't hungry earlier because they hadn't eaten lunch but their pair had. It also served to mitigate mid-afternoon food-coma somewhat.