“Eating turkey makes you sleepy.”

The idea that a serving of turkey inevitably leads to a post-meal nap is a widely held belief, often surfacing around holiday feasts. This common misconception likely stems from the fact that turkey contains tryptophan, an essential amino acid. Tryptophan is indeed a precursor to serotonin, a neurotransmitter that contributes to feelings of well-being, and melatonin, a hormone that regulates sleep. However, the connection between turkey and drowsiness is not as direct as many assume.

While turkey does contain tryptophan, the amount present is actually quite small compared to other foods, such as cheese, nuts, or even chicken. More importantly, for tryptophan to have a noticeable sleep-inducing effect, it needs to cross the blood-brain barrier. This process is complex and can be inhibited by the presence of other amino acids, which are also abundant in protein-rich foods like turkey. Therefore, consuming turkey alone is unlikely to provide a sufficient dose of tryptophan to directly make you sleepy.

The real culprits behind that drowsy feeling after a big meal are far more complex than a single ingredient. Large meals, especially those rich in carbohydrates and fats, require a significant amount of energy for digestion. The body redirects blood flow to the digestive system, which can temporarily reduce blood flow to the brain, leading to a feeling of sluggishness. Additionally, consuming sugary foods can cause blood sugar levels to spike and then crash, further contributing to fatigue. Alcohol, often consumed during celebratory meals, also acts as a depressant and can certainly induce drowsiness, compounding the effect. It's the overall caloric load and nutrient composition of a large feast, rather than the turkey itself, that tends to bring on the post (Review)-meal slump.