By Megan Riddle, M.D. Ph.D.

Right now, you are being bombarded by messages about holiday weight gain. “Avoid those 5 holiday pounds!” “Drop the Egg Nog and drop that extra weight!” The media reminds us again and again that American gluttony will have us bursting at the seams. So, here’s the secret all those news articles leave out: No one knows where that five pound number came from.