Turkey does contain L-tryptophan, an essential amino acid with a documented sleep inducing effect. L-tryptophan is used in the body to produce the B-vitamin, niacin. Tryptophan also can be metabolized into serotonin and melatonin, neurotransmitters that exert a calming effect and regulates sleep. However, L-tryptophan needs to be taken on an empty stomach and without any other amino acids or protein in order to make you drowsy. There’s lots of protein in a serving of turkey and it’s probably not the only food on the table.
Here are a few other things that add to your food coma-like state after dinner:
- Fats: Fats slow down the digestive system, giving Thanksgiving dinner plenty of time to take effect. Fats also take a lot of energy to digest, so the body will redirect blood to your digestive system to tackle the job. Since you have less bloodflow elsewhere, you will feel less energetic after eating a meal rich in fats.
- Alcohol: Alcohol is a central nervous system depressant. If alcoholic beverages are part of the holiday celebration, then they will add to the nap-factor.
- Overeating: It takes a great deal of energy to digest a large meal. When your stomach is full, blood is directed away from other organ systems, including your nervous system. The result? You will feel the need to snooze after any big meal, particularly if it is high in fats and carbohydrates.
- Relaxation: Although many people find the holidays stressful, the most relaxing part of the festivities is likely to be the meal. No matter what you may have been doing throughout the day, Thanksgiving dinner provides an opportunity to sit back and relax — a feeling that can carry over after the meal.
So don’t blame the bird if you are sleepy after a big Thanksgiving dinner. Your drowsiness is actually a combination of the type of food, amount of food, and celebratory atmosphere.