We’ve all heard it before: you feel so sleepy after a Thanksgiving meal because of the main event: the turkey. For years, people have credited extraordinary levels of tryptophan in turkey as the reason we all feel the need to nap after the annual feast. But contrary to this popular mythology, tryptophan is probably not he largest responsible party for your post-meal exhaustion.
Tryptophan is an essential amino acid, which means it’s something that our bodies need but do not produce naturally. Your body uses tryptophan to help make vitamin B3 and serotonin, which is a neurotransmitter that sends chemicals to the brain to aid in sleep. But in order to get this essential amino acid, we have to eat foods that contain it.