Does turkey make you sleepy?

According to the Discovery Channel,

The right answer is false. Turkey does contain the amino acid tryptophan, which is a natural sedative, but so do plenty of other foods, such as chicken, beef, pork, cheese and beans. Not only do all of these foods also contain protein, which negates the effects of tryptophan, but we generally don't ingest enough at one sitting to feel it.

However, what does tend to make people exceptionally drowsy is eating a big, heavy meal — Thanksgiving dinner, for example. Blood is diverted to the digestive system to help tackle all the fats and carbohydrates you've consumed, which decreases blood flow to your brain and makes you feel lethargic. Drinking alcohol — while watching football or during the meal — only makes matters worse. So even if you didn't eat any turkey, you'd still feel like taking a nap afterward.

I guess eating everything on that table made me take a three hour nap on the couch listening to a loud American Chopper on the tube.