Why does eating turkey make people feel so sleepy?

Eating turkey does not make people feel sleepy. The notion that turkey causes drowsiness is a common misconception often attributed to the amino acid tryptophan. While turkey does contain tryptophan, the amount is not sufficient to cause a significant sedative effect. Factors like overeating, a large meal, and post-meal relaxation can contribute to after-meal sleepiness, regardless of the food consumed.