It’s almost Thanksgiving, and that means it’s time to feast, drink, spend time with family, give thanks — and time to nap. The turkey often gets the blame for post-Thanksgiving dinner sleepiness. And, while turkey does contain a brain chemical involved in sleep, you can’t blame your Thanksgiving fatigue entirely on the bird. The stuffing, potatoes, pie and alcoholic drinks combined are the more likely suspects.

So why does the turkey get the bad reputation for making us drowsy? Turkey does contain tryptophan, an essential amino acid that promotes the production of serotonin, a neurotransmitter, and melatonin, an important hormone that tells your brain it’s time to go to sleep. The body is unable to manufacture tryptophan on its own, so it must be obtained from food protein. And turkey is a great source of this essential acid.

But eating turkey by itself does not translate to increased serotonin or melatonin production in the brain. The tryptophan in meat, such as Turkey, often has to compete with the many other amino acids found in protein-rich foods. These other protein-rich foods can make it difficult for tryptophan to be circulated through the bloodstream to the brain.

Eating a large meal full of fats and sugars will make you tired even without tryptophan based main course. When your stomach is full, your brain gets a signal telling it to send blood and energy to help the body start to digest the meal. That means less blood and energy for the rest of you!

So this Thanksgiving, if you want to avoid feeling stuffed and sluggish after your meal take smaller portions, pile on the veggies and drink water instead of alcohol