I'm not sure who wrote this originally as it was sent to me via email, but I thought it was cute and appropriate.  Sorry to whomever I'm plagiarizing and I would give you credit if I knew who you were

'Twas the week after Christmas, and all through the house
  Nothing would fit me, not even a blouse.
  The cookies I'd nibble, the eggnog I'd taste
  All the holiday parties had gone to my waist.
  When I got on the scales, there arose such a number!
  When I walked to the store (less a walk than a lumber).
  I'd remember the marvelous meals I'd prepared;
  The gravies and sauces and beef nicely rared...
  The wine and the rumballs, the bread and the cheese
  And the way I'd never said, "No thank you, please."
  As I dressed myself in my husband's old shirt
  And prepared once again to battle the dirt...
  I said to myself, as only I can
  "You can't spend a winter dressed like a man!"
  So...away with the last of the sour cream dip,
  Get rid of the fruit cake, every cracker and chip.
  Every last bit of food that I like must be banished
  'Till all the additional ounces have vanished.
  I won't have a cookie, not even a lick,
  I'll want only to chew on a long celery stick.
  I won't have hot biscuits, or cornbread, or pie,
  I'll munch on a carrot and quietly cry.
  I'm hungry, I'm lonesome, and life is a bore...
  But isn't that what January is for?
  Unable to giggle, no longer a riot
  Happy New Years to All and to All a Good Diet!!