“Eating turkey makes you sleepy.”

Many people have heard that the reason for feeling sluggish after a big meal, especially one featuring turkey, is due to the tryptophan found in the bird. This idea gained traction partly because tryptophan is indeed an amino acid that the body uses to produce serotonin and subsequently melatonin, hormones known to regulate mood and sleep. The myth likely solidified in popular culture after scientific discussions about tryptophan's role in sleep regulation emerged in the late 1960s, leading to media articles in the 1970s that linked turkey to a "natural sleeping pill" effect.

However, the scientific reality busts this widespread belief. While turkey does contain tryptophan, it doesn't contain significantly more than other common protein sources like chicken, beef, or even cheese and nuts. More importantly, for tryptophan to have a noticeable sleep-inducing effect, it needs to cross the blood-brain barrier. When consumed as part of a protein-rich meal, tryptophan must compete with many other amino acids for absorption, meaning only a small amount actually reaches the brain. In fact, consuming carbohydrates *with* protein would be more effective at increasing brain tryptophan levels, as carbohydrates trigger insulin release, which helps clear other amino acids from the bloodstream, allowing tryptophan a clearer path.

The real culprits behind that post-meal drowsiness, often dubbed a "food coma" or postprandial somnolence, are a combination of factors unrelated to turkey's unique properties. Overeating, particularly large meals high in carbohydrates and fats, requires significant energy for digestion, diverting resources and leading to a natural dip in alertness. Alcohol consumption further exacerbates sleepiness. Additionally, our bodies have natural circadian rhythms that cause a dip in alertness during the afternoon, which often coincides with when many large meals are consumed. Therefore, the general indulgence of a feast, rather than the turkey itself, is what typically sends people searching for a nap.