constant theme of eating + Groundhog Day

As this movie left me with a certain amount of questions, I was looking through several discussions about it, here and on reddit, and I noticed that nobody has talked about the constantly present theme of eating. I did not exactly keep track but I think there was either someone eating or at least talking about eating in every scene of the movie, even if it's only a short "Have you eaten already?" or, for instance "I'll make you eat your hair". Adding to that is the fact that the second stage of the "sickness" was the refusal/inability to eat. Does anybody have any thoughts on that? It can't have been coincidental.
Another question I have, that I did not see discussed anywhere, what was the significance of them watching Groundhog Day?