Yes, it’s very true that turkey contains tryptophan, which does in fact help your body produce the “sleep chemical” melatonin. BUT, turkey contains basically the same amount as other meats, according to some research. Turkey also has high amounts of proteins, which will actually help keep you awake and energized.
So why are we sleepy after Thanksgiving dinner? It’s more likely just that – the rest of the dinner. Mashed potatoes, breads, pasta, stuffing/dressing (whatever your family calls it) are all starchy, and can make you feel drowsy and tired.