Thanksgiving Sleepiness: It’s Not Just the Turkey

After a big Thanksgiving feast, many Americans find themselves feeling a bit drowsy. It’s a familiar scene: gather around a table filled with delicious food, perhaps share some laughs, and then—bam—suddenly you’re fighting off a nap.

Traditionally, turkey gets the blame for this post-meal fatigue due to its tryptophan content, an amino acid often linked to sleepiness. However, the reality is that turkey isn’t uniquely sleep-inducing; it’s similar to other meats like chicken or beef.

According to the National Council on Science and Health, turkey contains about the same amount of tryptophan as various other types of meat. Data from the USDA shows that roasted turkey breast has around 488 milligrams of tryptophan per 170 grams, which matches that of roasted chicken and is actually less than what can be found in some cheeses and soy products.

For instance, a typical 3-ounce serving of turkey might have about 244 milligrams of tryptophan, which is far lower than the gram-level amounts often tested in sleep studies. This suggests the sleepiness often felt after a large meal isn’t solely because of turkey.

Body chemistry plays a role here as well. When you consume a protein-heavy meal, it floods your bloodstream with various large amino acids that compete to enter the brain. Tryptophan, while important, isn’t the leading player in this mix.

This means turkey doesn’t boost your brain’s tryptophan levels enough to significantly increase serotonin and melatonin—those hormones that help regulate sleep.

So, if you’re wondering why you might feel like curling up for a nap after the holiday dinner, it turns out the issue lies more with the larger act of eating a big meal. This phenomenon, scientifically known as postprandial somnolence, usually peaks one to two hours after eating and tends to intensify after particularly large, energy-dense meals.

Feasting on rich sides like stuffing, potatoes, pie, or gravy requires a lot of energy to digest. This process directs blood flow away from the brain and toward your intestines, contributing to that overwhelming desire to doze off.

In addition, the Sleep Foundation states that feeling sleepy after eating can be influenced by the size of the meal and the type of foods consumed, particularly those high in carbohydrates or fats, which can lead to rapid shifts in blood sugar levels.

Rich side dishes and desserts can spike insulin, leading to changes in amino acid balance in the bloodstream, thus enhancing the transport of tryptophan to the brain. So, perhaps next time you find yourself nodding off after dinner, consider the whole experience—from the feast itself to the mix of foods on your plate.