Are you looking forward to Thanksgiving dinner? It can be a great opportunity to spend time with family or reconnect with friends while enjoying a delicious meal. But feeling bloated and exhausted after dinner could cause your excitement to be short-lived. Who knew eating could take that much out of you? The turkey, large quantities of carbs and possibly alcohol that are part of the traditional Thanksgiving meal create the perfect storm for tiring you out.

You might have heard of the sleep aid melatonin, a hormone that acts as an internal clock. Melatonin levels are low during the day when we are meant to be awake and high at night when it’s time for bed. Turkey contains protein that is in part made from an amino acid called tryptophan. The body uses tryptophan to make a chemical called serotonin, which in turn produces melatonin. When you eat turkey, your melatonin levels rise. This spike corresponds to an increase in fatigue.

Most of us have heard about how turkey and tryptophan can make you tired. But, we can’t blame only the turkey! The body follows the directions of the nervous system, which operates under the sympathetic or the parasympathetic response. The sympathetic response is commonly known as the “fight or flight” system, which prepares the body for strenuous activity. This includes an increase in heart rate and blood pressure. In contrast, the parasympathetic response is referred to as the “rest and digest” system and kicks in following a big, long meal. In the rest and digest “setting,” your heart rate decreases and your muscles relax, almost as if you were trying to fall asleep.

If you enjoy wine or other alcoholic beverages with your Thanksgiving dinner, it may be another reason you start to feel sleepy. Alcohol acts as a depressant to the central nervous system. Nerve cells (neurons) that normally fire rapidly are slowed by the effects of alcohol. This lag in neuronal firing is what leads to the drowsiness that lingers after a big meal.

To avoid feeling drowsy during the holidays, make sure to get a good night’s sleep the day before your celebrations. Try eating smaller quantities or “mini meals” throughout the day rather than enjoying everything in one sitting. By spacing out your eating and curbing your alcohol consumption, you may be able to kiss the dreaded “food coma” goodbye.