It goes like this: tryptophan, an amino acid, helps create seratonin. Among other things, seratonin also helps regulate your sleep cycle, which may be why folks have been perpetuating the tryptophan lie for so many years. While the substance does exist in turkey, it's hardly enough to cause the immediate drowsiness we associate with the holiday meal.

For that, we must blame all the other things we're stuffing into our mouth holes, like mounds of mashed potatoes, tubs of butter, wagon loads of rolls and trays of pies. So there you have it: turkey makes you sleepy but only because you're eating it with 3,508 calories of other equally coma-inducing foods, you glutton. Pass the gravy, please.