“Eating turkey makes you sleepy due to its tryptophan content.”

The idea that eating turkey leads to an irresistible urge to nap is a widely accepted notion, particularly after large holiday feasts. This common belief pinpoints tryptophan, an amino acid found in turkey, as the culprit responsible for the post (Review)-meal sluggishness. The myth likely gained traction due to tryptophan's known role as a precursor to serotonin and melatonin, neurotransmitters associated with relaxation and sleep. People often connect the feeling of a "food coma" directly to the turkey on their plate, making it an easy and memorable explanation for their drowsiness.

However, scientific evidence busts this popular misconception. While turkey does contain tryptophan, it's not present in significantly higher amounts than in many other common protein sources like chicken, beef, or even cheese. For tryptophan to effectively induce sleepiness, it needs to cross the blood-brain barrier, a process that is actually hindered by the presence of other amino acids found in protein-rich foods. The amount of tryptophan in a typical serving of turkey is far less than the dosage used in supplements designed to aid sleep.

The real reasons behind that sleepy feeling after a big meal are far more complex and involve several factors working in combination. Overeating, especially large quantities of carbohydrate-rich foods like stuffing, mashed potatoes, and desserts, causes a rapid rise and subsequent crash in blood sugar levels, contributing significantly to lethargy. Alcohol consumption further amplifies drowsiness by acting as a depressant on the central nervous system. Additionally, the body's digestive processes divert blood flow to the stomach and intestines, away from the brain, which can also contribute to a general feeling of low energy and sleepiness, a phenomenon known as postprandial somnolence. So, while turkey is a delicious part of many meals, it's the overall feast, rather than the bird itself, that usually sends us searching for a couch.