If you’ve ever had a big meal—think Thanksgiving dinner or a celebratory buffet where you feasted on a bit more rounds of food than you might have needed—you might have found yourself getting up from the table wishing it was time for bed or dozing off in your recliner in front of the TV.
Feeling sleepy after eating is a fairly common phenomenon, but sometimes, you feel more than a little tired—you frankly feel like you’re going to zonk out and fall asleep right there and then.
Often dubbed a “food coma,” feeling exhausted after eating can make it hard to go about the rest of your day.
So, what is a food coma, and how do you get out of a food coma and revive yourself? In this article, we will discuss what a food coma is, what can cause it, and how to get out of it!
We will cover:
- What Is a Food Coma?
- What Causes a Food Coma?
- What to Do to Get Out Of a Food Coma
Let’s dive in!
What Is a Food Coma?
A food coma is a colloquial term used to describe the feeling of sleepiness or fatigue after eating. The medical term for a food coma is postprandial somnolence.
Although there is a medical term to describe a food coma, the entire phenomenon is rather poorly understood and vague in terms of what actually constitutes a food coma or even postprandial somnolence.
Food comas tend to occur after eating a large meal, particularly if it is either rich and fatty or high in carbohydrates and/or accompanied by alcohol.
However, mini-food comas can occur after smaller meals as well, particularly if you have sensitivities to the foods you ate or if you consumed foods high in certain nutrients like tryptophan.
For example, some people experience a post-lunch slump, which essentially involves a dip in energy after eating lunch that might leave you feeling like you want to take a nap at your desk.
This might not be a full-blown “food coma,“ but there really isn’t a specific set of criteria that must be satisfied to qualify as such. Any noticeable feeling of sleepiness after eating can be considered postprandial somnolence.
Symptoms of a food coma can vary but generally involve sleepiness, physical exhaustion, low energy levels, lethargy, sluggishness, poor concentration, and poor attention.
Despite the name, there is no true “coma“ aspect of a food coma, and it should not be confused with the very dangerous medical condition of a coma. With a food coma, there is no unintentional loss of consciousness but rather a feeling of fatigue or sleepiness that washes over you or a draining of energy that leaves you wanting to fall asleep.
What Causes a Food Coma?
Although people seem to experience food comas rather often, scientific research surrounding the pathophysiology is scarce.
However, there are various theories about the potential causes of food comas, including the following:
#1: A Food Coma May Be Caused By Changes In Blood Circulation
Historically, scientists believed that food comas were primarily triggered by changes in blood flow after eating. It was thought that as more blood was sent to the digestive tract to begin digesting food, blood was diverted away from the brain, causing a relative lack of oxygen and glucose availability to brain cells, resulting in sleepiness.
However, for the most part, this theory has been largely invalidated by subsequent studies that have found that the brain still receives more than enough blood flow during situations like exercise, where the muscles, rather than the intestines, are competing for oxygenated blood.
It seems unlikely that the brain would not be able to receive adequate blood flow after eating if it can during exercise. (Would the digestive tract really need that much more blood flow than all of your skeletal muscles that are working during exercise?)
With that said, one study did find that brain blood flow decreased after eating lunch, although this seemed to occur in subjects who had skipped breakfast, so maybe there is a time interaction or fasting influence on hemodynamics.
#2: A Food Coma May Be Caused By Eating Large Meals
Typically, food comas are more likely to occur after eating a large, heavy meal.
For example, one study found that men who overindulged in a meal of pizza reported feeling more tired, lethargic, and low-energy in the 4-hour window after eating than the men who ate until they were satisfied but not overstuffed.
There was even an older study that found that people who ate a heavier lunch were not only more sleepy in the two hours after eating than those who ate a light lunch containing just 1/3 as many calories, but they also had impaired driving ability, demonstrating more difficulty staying in their lane.
Animal studies have found that meals high in protein and salt can increase the length of sleep after eating.
Meals that are larger and higher in calories take longer to digest because both increased volume and increased caloric content slow the rate of gastric emptying.
It actually takes a fair number of calories to digest and absorb nutrients—particularly protein and fat—which is termed the thermic or thermal effect of food.
Therefore, it might be that the metabolic demand of digesting a large, rich meal results in a high energy output that leaves you feeling tired.
#3: A Food Coma May Be Caused By Eating Certain Nutrients
Meals high in carbohydrates can cause a food coma because they can cause a relative increase and then decrease in blood sugar levels.
Studies suggest that high-carb foods may also increase the production of tryptophan, an amino used by the body to synthesize various proteins, as well as niacin (a B vitamin) and a molecule known as 5-hydroxytryptophan or 5-HTP.
Because 5-HTP is a precursor for the neurotransmitter serotonin, and serotonin helps regulate sleep, it’s normal to feel tired after eating foods high in tryptophan.
High-protein meals can contain lots of tryptophan, leading to lethargy after eating. Foods high in tryptophan include chicken, turkey, pork, fish, eggs, milk, cheese, and tofu.
Finally, eating foods high in melatonin can increase the levels of this melatonin in your body and can leave you feeling tired after eating.
Examples of foods high in melatonin include milk, tart cherries, pistachios, grapes, mushrooms, corn, oats, eggs, rice, and bananas.
#4: A Food Coma Can Occur If You Drink Alcohol With Your Meal
Most people who imbibe in alcohol with a meal will notice feeling particularly tired after eating. Alcohol can cause drowsiness because it’s a nervous system depressant.
#5: A Food Coma May Be Caused By Changes In Hormones
Finally, some of the same hormones and nervous system pathways involved in digestion also regulate sleep.
The parasympathetic nervous system is commonly referred to as the “rest and digest“ nervous system, pointing to the fact that it governs both of these activities. This overlap may be responsible for some of the food coma sensation.
Additionally, some of the hormones secreted around mealtime or after eating can affect energy levels. For example, orexin, which is a hormone that increases hunger and alertness, is inhibited after eating, and melatonin, which is a hormone involved in the sleep-wake cycle, increases as the digestive process begins.
It is this neurohormonal response that seems to be the current prevailing theory underlying the mechanism of action for developing a food coma.
What to Do to Get Out Of a Food Coma
So, whether you’ve eaten too much or your meal just seemed to zap your energy levels for one reason or another, how do you get out of a food coma and feel energized again?
Here are a few tips that may help you feel more awake after eating:
- Go for a walk.
- Get fresh air outside.
- Do 5 minutes of exercise like jumping jacks, running in place, squats, running up the stairs, or jumping rope.
- Drink 12-16 ounces of water.
Getting the body moving can activate the sympathetic nervous system and can increase circulation, both of which can help you feel more alert and energized.
Although these tips won’t help break a food coma once you have one, they can help prevent food comas:
- Eat smaller, balanced meals
- Eat more frequently
- Get enough sleep at night
- Limit alcohol
- Be mindful of your caffeine intake
- Minimize your intake of simple sugars
- Consider paring back on foods high in tryptophan when you need to feel alert after eating
- Keep a food diary to notice if certain foods cause sleepiness
Food comas, or feeling tired after eating, usually isn’t a cause for concern, but if it’s happening frequently, or is disruptive to your life, speak with your doctor about possible underlying medical conditions or necessary dietary modifications.
If you are feeling strangely sleepy after eating carbohydrates in general, check out our article discussing fatigue after eating carbs.
