Happy Thanksgiving! If you are heading to a Thanksgiving feast, chances are that you’ll be stuck in at least one conversation about tryptophan. Yes, we all know the claim that the loud snoring that begins after the Thanksgiving meal is caused by that rogue amino acid. However, tryptophan may be innocent! True, tryptophan can be converted to serotonin, which causes sleepiness. But, tryptophan needs to be consumed on an empty stomach to be effective, and the protein in turkey (let alone all the other foods consumed at the Thanksgiving table) prevents this possibility. It’s possible that excessive carbohydrate consumption (think stuffing and sweet potato pie) is to blame. The carbs cause the pancreas to pump out insulin. Insulin busies the other chemicals running through your bloodstream, clearing the way for tryptophan to arrive unhindered at the transporters that shuttle amno acids into the brain. Most likely of all, post-Thanksgiving fatigue is caused by the diversion of blood from the nervous system to the stomach to deal with the excessive amount of food there.