Thanksgiving is coming up and with that comes overindulging for many, followed by the traditional post-turkey “coma” that many experience after the lengthy, filling dinner. Along with loosening our belt buckles with each passing hour comes much talk about how the turkey dinner made us sleepy.MORE: The Beauty Benefits of Thanksgiving Foods (Infographic)The reality, though, is that our Thanksgiving turkey typically gets a bad rap and shouldn’t be blamed (solely) for our passing out on the couch during the football game on TV. Turkey contains L-tryptophan, an amino acid—the building blocks for protein. In addition to turkey, tryptophan is found in chicken, duck, cheese, eggs, fish and even yogurt. The body breaks down the tryptophan in these foods to produce serotonin, a brain chemical that improves our sleep and helps us feel calm and relaxed. In turn, serotonin is then used to make melatonin, a hormone that, when present during darkness, induces sleepiness.Turkey actually contains the same amount of tryptophan as many other foods, and even a little less so than chicken. We don’t usually fall asleep after having a typical mid-week chicken dinner, so something else must be at play than simply having a lot of tryptophan-containing turkey for Thanksgiving.The answer lies in all of the carbohydrates we pile on our plates during the holiday meal. Scoops of stuffing, mashed potatoes, rolls and pie are just as much to blame as the turkey. Consuming even a small amount of carbohydrate can significantly increase your serotonin levels, giving you that relaxed feeling.MORE: Stress Reduction DietAn even greater sleep-inducing effect is found when we combine foods that contain tryptophan with carbohydrates. Tryptophan has some difficulty getting through the blood-brain-barrier all by itself. When combined with a small serving of carbohydrate, tryptophan easily gets across. Once we finish off all of the additional carbs on our plate, the tryptophan combines with the added serotonin, and we become sleepy.With Thanksgiving dinner also often comes increased consumption of alcohol, thereby inducing sleep—though, typically of poor quality. We are more relaxed from the alcohol, but our bodies also need to work extra hard to process the multiple plates of food, utilizing more energy than normal.Although the post-turkey “food coma” is a tradition in many families, try to avoid a nap if you struggle regularly with insomnia. If you don’t have trouble sleeping at night, a quick, 20-minute power nap earlier in the afternoon can help give you the additional energy you might require for all that Black Friday shopping!MORE: 5 Ways to Boost Your Energy (Infographic)