Contrary to popular belief, turkey does not contain a lot of tryptophan, an essential amino acid that can influence mood and sleep as it contributes to serotonin and melatonin production. While tryptophan may promote relaxation, overall diet and lifestyle greatly affect sleep quality. Eating foods with tryptophan in addition to a large number of carbohydrates leads to sleepiness, and carbohydrates come from the other typical foods at the Thanksgiving table, such as breads, potatoes, peas, corn, sugary drinks, and desserts. Overeating and consuming a lot of carbs and calories in a short time can also make you feel sleepy. In addition, the time of year and changes in metabolic activity during digestion can also play a role in holiday sleepiness. Therefore, it is not just the turkey that makes you sleepy after Thanksgiving dinner, but rather a combination of factors.