Why You Sleep on Thanksgiving

Indulging in a gluttonous hours-long dinner, especially one that includes dessert and drinks, can leave you with barely enough energy to stumble to the couch in time for football. But it's not just the extra calories that make you feel drowsy on Thanksgiving. Here are four reasons the holiday can leave you feeling so sleepy:

1) The Turkey and Trimmings
It's well known that turkey is loaded with tryptophan, an amino acid that promotes the production of serotonin, a brain chemical that's involved in REM sleep and has a calming effect. Whether bingeing on the bird is the most effective means of achieving the sedating effects associated with tryptophan is less clear. A study published last month in the Canadian Journal of Physiology and Pharmacology asserts that, in order for tryptophan to be absorbed most effectively from the blood stream into the central nervous system, it must be combined with a high-glycemic carbohydrate, which reduces the level of neutral amino acids that compete with tryptophan for absorption. In other words, if you ate only turkey, that might not help you sleep. But combine it with Thanksgiving trimmings like mashed or sweet potatoes, and you're likely to feel the effects. (And if you want to find out which foods are the biggest Thanksgiving calorie culprits, check out our list of the most fattening foods of fall.)

2) A Chance to Relax
Most of us don't get the seven to eight hours of sleep each night that specialists recommend. That can be especially true during the holiday season, when our evenings are filled with parties and shopping trips. So on Thanksgiving, when many of us finally get a chance to relax, our bodies are anxious to catch up on missed sleep. "Thanksgiving and sleepiness go together like turkey and pumpkin pie," says Dr. Ralph Downey III, chief of sleep medicine at the Sleep Disorders Center at California's Loma Linda University Medical Center, in a release from the American Academy of Sleep Medicine. "We nap or feel drowsy because we are in a relaxed state. When we finally relax, our brain is primed for sleep from all the days when it has not had as much." Just don't sleep too long or too late. A longer nap, or a nap taken too close to bedtime, may adversely affect the length and quality of your nighttime sleep. A short 20- to 30-minute midafternoon nap, however, should provide a "significant benefit" for improved alertness and performance without interfering with your nighttime sleep, according to the National Sleep Foundation. In fact, afternoon naps might even boost your mood and your mental performance the next day, according to new research at NewYork-Presbyterian Hospital/Weill Cornell Medical Center. So don't worry if you doze off on the couch after your Thanksgiving meal. Just make sure someone wakes you in time for dessert. For more tips on getting a great siesta, check out our seven secrets to a great nap.

3) A Soporific Combo
An Australian study published in February in the American Journal of Clinical Nutrition found that eating carbs that quickly raise blood sugar, especially if you do it four hours before bedtime, may help you fall asleep faster. That means carbs with a high glycemic index, including traditional Thanksgiving sides like mashed and sweet potatoes, rolls, and bread stuffing.

4) Drinking Up
If you want a good night's sleep, say specialists, avoid alcohol or caffeinated drinks. Too bad they both often accompany a Thanksgiving meal. While alcohol initially acts as a sedative, making it seem easier to fall asleep, it tends to disrupt sleep in the second half of the night; as the drink wears off, you may wake up and then have difficulty going back to sleep. Drinking alcohol may also make insomnia worse in those who already suffer from it. But don't try to counter the effects with caffeine. A coffee, even in the early afternoon, can make it difficult to fall asleep at night. Caffeinated food and beverages—including coffee, tea, sodas, and even chocolate—remain in the body on average three to five hours, but they can affect some people up to 12 hours later, according to the National Sleep Foundation. So stick to decaf and sips of wine if you want to stay alert through the meal but sleep well that night.