The holidays take its toll on everyone. A pretty known digiscrapper I know even gained 12 pounds over the holidays. Must be all the cooking she did for her six kids.
But even if it's only two pounds or ten that you want to lose, you might want to reconsider popping that diet pill. After all, with basically the same discipline you'd require popping those pills everyday and the same amount you'd spend on them, you can lose weight more healthily. Not as fast maybe, but healthily, and probably in a more permanent way (unless you binge again).
Go grab a copy of Readers Digest Asia (January issue) for the weight loss tips that work best. Some are as easy as making sure half of what you eat are veggies, taking a great many number of steps and eating spicy food.