Toddling away from the table with a turkey-stuffed tummy on Thanksgiving usually means one thing: Naptime is near.

Most of us link the post-Thanksgiving penchant for dozing off on the couch to tryptophan [TRIP-toe-fan], a sleep-inducing amino acid found in turkey. But this “turkey coma” so many of us face after a big holiday meal actually has more to do with everything else on your plate than the tryptophan in turkey.

Tryptophan can cause drowsiness, but it works best on an empty stomach… and the Thanksgiving tummy is anything but. Eaten alone, the tryptophan in turkey can cause sleepiness, but the chemical doesn’t fare well when it shares stomach space with amino acids from other foods.

That’s why experts believe Thanksgiving drowsiness is probably less a turkey coma and more a “cranberry sauce, sweet potato, green bean casserole, two pieces of pumpkin pie and turkey coma.”

An overstuffed tummy has been shown to lead to increased drowsiness, as does the wine that often accompanies a holiday meal. And a long day spent cooking or traveling could also be part of what prompts the post-meal nap.

Turkey isn’t the only food with tryptophan that most of us eat regularly, either. Beef and chicken contain just as much of the amino acid, and no one ever complains of falling into a hamburger coma.

You may still need to snooze after a big Thanksgiving meal, but don’t blame it on the turkey when you curl up on the couch.