Also known as after dinner deep, postprandial sleep, the itis, food drunk or food coma, postprandial somnolence is a state of drowsiness human beings tend to feel after eating. There are two components to it. The first is a general state of low energy related to activation of the PNS (parasympathetic nervous system) in response to mass in the gastrointestinal tract, and the other one is a specific state of sleepiness. There are several theories that have been put forward to explain this including neurohormonal modulation of sleep through digestive coupled signaling, decreased blood flow to the brain and vagal stimulation. However, none of these theories have been well tested to establish that they are the true cause of postprandial sleep.
Myths About the Causes of Postprandial Somnolence
Aside from the unproven theories, there are also a number of myths that a majority of people believe concerning the cause of postprandial sleep. It is worth noting that these are plain misconceptions and there isn’t any scientific evidence to back these claims.
Cerebral Blood Flow and Oxygen Delivery
After eating, the passage of food into the gastrointestinal tract stimulates an increase in blood flow to the stomach and intestines. The assumption is that to facilitate this increased blood flow to the stomach, the blood flow to the brain is reduced. This isn’t true because the increased blood flow is enabled by a diversion of blood from skeletal muscle tissue and also an increase in volume of blood pumped by the heart each minute. The flow of oxygen and blood to the brain is very well regulated and there is nothing to indicate that there is a drop after having a meal thus canceling this theory.
Turkey and Tryptophan
This myth is based on the fact that turkey contains high volumes of tryptophan (an amino acid used in the biosynthesis of protein whose side effects include drowsiness and nausea among others when in large quantities). People believe that the tryptophan is what causes drowsiness any time one has a meal that includes turkey. Tests have however shown that the tryptophan content in turkey is almost equivalent to the one in other meats such as beef, chicken among others meaning that turkey doesn’t have a bigger role to play in postprandial somnolence as compared to other meats. Other foods, particularly soybeans, sunflower and sesame seeds as well as certain cheeses have a high tryptophan content and may therefore cause some drowsiness when consumed in large quantities.
What Causes Food Coma
Now that we’ve already set the record straight in terms of myths and misconceptions about food comas, let’s look at the facts. Again, it is important to note that as much as there have been extensive research on this matter, the findings haven’t been very conclusive and it is almost impossible to say for a fact that doing this and that, or eating this and that will give you postprandial somnolence while avoiding these particular behaviors or keeping away from these particular type of food is guaranteed to protect you from getting into a food coma after having a meal. The main reason why the findings have been inconclusive is because human beings are all different, have different rates of metabolism as well as different sleeping patterns and unique eating habits making it very difficult to establish a common trend.
Now all that having been said, researchers have still presented a number of theories to explain the tiredness after eating but they generally agree that it is a natural response and shouldn’t be much cause for concern. So, below are a few reasons that suggest why someone may tend to feel tired after a meal.
Type of Food Eaten
Foods rich in carbohydrates and protein have a higher probability of making you feel drowsy once you’ve eaten them. Researchers believe that the drowsiness is caused by an influx of serotonin (a chemical that influences the body’s sleeping pattern and regulates mood changes) inside the body. They argue that the drowsiness is as a result of a chain of events which starts with consumption of proteins and carbohydrates. The proteins then stimulate the production of an amino acid we referred to earlier as tryptophan which then helps the body produce serotonin. Carbohydrates on the other hand, help the body to absorb the tryptophan which just stimulates the whole process. Based on this, the type of food eaten could potentially have an influence on the feeling of drowsiness moments after lunch or dinner.
Amount of Food Eaten
Now that it is established that the type of food eaten might have a bearing on postprandial somnolence, it probably goes without saying that the quantity of food eaten could also have an impact on energy levels, maybe even more significant than the type of food. The researchers say that a larger meal is more likely to cause postprandial sleep. This is because a larger meal contains more protein and more carbohydrates making the chain reaction even larger because of the quantities involved. A larger lunch has a higher chance of reducing your attention because it causes your blood sugar to rise and consequently reducing the energy levels in the body.
Poor Sleep at Night
A proper night’s sleep has many benefits including keeping your heart healthy, reducing stress levels, improving your attention and concentration thus making you more alert and so much more. If you sleep well, you are less likely to get tired easily during the course of the day because in a way, your batteries have been charged. This means that even after you’ve had a meal and the proteins stimulate production of serotonin, you are less likely to be affected by it because the body already feels energetic and alert. On the other hand, if you haven’t been sleeping well, a small increase in serotonin levels inside your body will have a greater impact thus making you feel tired and very susceptible to sleep.
Having Alcohol with Your Meals
When you have alcohol with your food, there’s a very high chance that you may start feeling a drowsy effect within no time. This is because unlike other drugs, alcohol isn’t a stimulant, it is a depressant and has a sedative effect. It will therefore depress your central nervous system which in turn relaxes you and makes you drowsy. This is made even worse by the food you’ve just eaten because of the serotonin produced as discussed earlier. The effect is almost twice as bigger.
How Do You Prevent A Food Coma?
Now that the causes of a food coma have been established, one can almost deduce for themselves the best way to prevent a post lunch dip.
Eat Less but Often
Other than having a large meal all at once, you could eat little portions of food but regularly. This reduces the impact of serotonin while also maintaining your energy levels.
Get Good Quality Sleep
Try as much as possible to get a proper night’s sleep if you don’t want to experience energy slumps during the day. As earlier stated quality sleep will keep your energy and concentration levels high enough.
Be Active After A Meal
Try and get your blood flowing after a meal. You can go take a walk, ride a bike or even engage in light sports such as tennis or soccer. Once you have your blood flowing, the chances of a sleep coma are very minimal.
As already mentioned, alcohol will make you drowsy and thus compound the effects of a heavy lunch.
Laila Azzahra is a professional writer and blogger that loves to write about technology, business, entertainment, science, and health.