It's a myth that's been passed down from generation to generation: the obligatory post-Thanksgiving nap is caused by all the pesky tryptophan in the turkey. But we've been blaming the bird for too long, folks, because turns out tryptophan is the lie we tell to make ourselves feel better after eating our weight in fatty, carby, meaty food.
The folks at Huffington Post popped the tryptophan tall tales, explaining the science behind those heavy eyelids. 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.