Thanksgiving’s official mascot isn’t totally to blame for your holiday food coma. Turkey does contain tryptophan, an essential amino acid needed to make serotonin, a precursor to sleep-regulating melatonin, says Raj Dasgupta, M.D., a pulmonary and sleep specialist at the University of Southern California. But that’s not the only reason you feel sleepy—all those yummy dishes and desserts you enjoy alongside turkey tend to be high in carbs, which contribute to post-meal sleepiness, as does overeating in general, he adds. An evening espresso to wake yourself up sounds like a good idea, but it can backfire by keeping you up later that night when it’s really time for bed. And while a nap might be tempting, it can similarly mess with your nighttime sleep. Instead, try Dr. Dasgupta’s tips for…