We’ve all been there: that overwhelming urge to lie down and take a nap after eating. Feeling subdued after eating is normal, but feeling sleepy and uncomfortably full is especially common around Thanksgiving and other holiday gatherings when we’re more likely to eat richer foods — and reach for extra helpings.
This feeling of drowsiness and fullness after eating is commonly called a food coma, but it turns out that there is a scientific term for it, too: postprandial somnolence. Read on to learn about food coma symptoms, causes, and prevention tips, as well as how to know when your food coma symptoms might warrant seeing a doctor.
What is a food coma?
“Food coma, or postprandial somnolence, is the feeling of sleepiness or drowsiness after eating,” says William Ja, Ph.D., associate professor, Department of Neuroscience at The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology.
“It’s not actually a coma, which should go without saying,” says Christine Byrne, dietitian and owner of Ruby Oak Nutrition. “It’s getting up from the table, or maybe 15 to 20 minutes after a meal, and you’re just hit with this wave of tiredness.”
Food coma symptoms
“An individual would experience feelings of extreme fatigue and desire to sleep after a meal,” says Marie-Pierre St-Onge, Ph.D., founding director of the Center of Excellence for Sleep and Circadian Research at Columbia University and author of “Eat Better, Sleep Better. “This is typically accompanied by reduced alertness and accuracy in tasks requiring attention.”
It’s normal to feel full after any meal, but if you’ve over-indulged and wonder if you’re heading for a nap, common symptoms of a food coma include:
- Sleepiness
- Drowsiness
- Lethargy
- Difficulty focusing
- Bloating
- Gas
- Stomach cramps
What causes food comas?
There are several scientifically backed reasons why you feel tired after eating, but food comas have not been extensively studied in humans. Still, several possible factors can contribute to food comas, including eating a large meal, consuming foods high in protein, salt, or fat, alcohol intake, and sleep quality.
Eating a big meal
Eating a large meal is one of the most likely causes of food comas. “When you eat food, your body redirects a lot of blood flow and energy to your digestive system, which can make your body feel really tired,” Bryne says. “That happens no matter what you eat, but when you eat a lot at once, it happens significantly.”
“At the ‘food’ level, it seems pretty clear that bigger meals lead to more post-meal sleepiness,” Ja says. A research study conducted by Ja and other researchers on postprandial sleep in fruit flies found that, on average, flies log more sleep after eating than before. “We basically looked at the thousands of feeding events or meals that we had data for and asked, ‘What does fly sleep look like before and after eating?’ We did additional experiments to show that this was ‘real’ sleep, and not just flies not moving around because they ate a lot,” Ja explains. “We were then able to take our data set and ‘sort’ it in different ways to ask how meal components impact sleep. For example, by grouping the meals into small, medium, and big meals, we could see that the bigger the meal, the greater the post-meal sleep.” Ja is quick to point out that the fruit fly study results may or may not reflect anything in humans.
One small 2018 study looked at the eating patterns of truck drivers in Brazil and found an association between what the drivers ate and how sleepy they felt — study participants who ate a “prudent” diet (as opposed to traditional or Western meals) were less sleepy.
Meals high in protein and salt
In the fruit fly study, Ja and his team sorted the data to examine other components, and by doing so, “we could see that protein and salt intake also seem to drive post-meal sleep,” he says. “Surprisingly, sugar did not have this effect. Everything we looked at happened in the 20 to 30 minutes following eating. So, it’s possible that sugar does have an effect on sleep, but at a longer time scale.”
Foods high in fat
Bryne says it is possible that meals high in fat can contribute to postprandial somnolence, though conclusive studies have not yet been conducted. “Fat is more calorie dense than protein or carbs, so it would make sense that if you’re eating a meal that’s high in fat, you’re probably eating more calories overall, and food does take more energy to break down,” Bryne says.
St-Onge says that some experts suggest that high-fat meals lead to increased levels of inflammation that promote sleepiness. She points to a study that noted that IL-1, a group of proteins that play a key role in fighting infections and regulating inflammation, may be partially responsible for this.
Alcohol intake
Alcohol can make you sleepy, too. “Alcohol is a sedative,” Bryne says. “Some people might think [the food coma is caused by] the turkey or steak meal, but the bottle of wine you’re drinking is contributing as well.”
Sleep quality the night before
Another factor that might be contributing to feeling sleepy after eating includes the quality and duration of sleep you got the night before. If your sleep quality was poor, you’re more likely to start the day already feeling sleepy, unfocused, or lethargic.
Does tryptophan make you sleepy?
A lot of people believe tryptophan is the cause of food comas, particularly around Thanksgiving when tryptophan-rich foods such as turkey are served. But chances are you’re not eating enough turkey for it to be the only reason you feel tired after eating.
“People talk a lot about tryptophan because it’s an amino acid. It’s found in protein as a precursor, which means it’s a building block for melatonin, a hormone that regulates your circadian rhythm and can make you tired,” Bryne says. “But you’re not getting enough tryptophan through food to produce enough melatonin to really be having that effect. While that’s possible, it’s more likely just the quantity of food that you ate.”
Plus, poultry isn’t the only source of tryptophan — you’ll find this amino acid in many other foods, including cheese, egg whites, fish, milk, peanuts, and pumpkin and sesame seeds, according to the U.S. National Library of Medicine (NLM). In fact, a serving of roast turkey breast has 488 milligrams of tryptophan, which is actually less than a comparable serving of salmon (570 mg). So, it’s possible tryptophan plays a role in making you sleepy. But if you don’t typically experience a food coma after a salmon dinner, something else may play a role beyond this amino acid.
How to prevent a food coma
Feeling sleepy after eating is normal, but it can be problematic if you need to focus on other tasks such as working, studying, socializing, or taking care of your family. Here, Bryne offers some tips for preventing or counteracting a food coma.
Eat smaller portions or spread meals out throughout the day
Eating less or spreading out your meals over the course of the holiday can help reduce feelings of tiredness because your whole digestive system doesn’t have to perform as much work at once.
Choose balanced meals
Byrne says it’s okay to eat big meals and the foods you love, but it can be helpful to have a variety of different foods on your plate. “You’ll probably feel your best if a big meal has a mix of protein, carbs, and fat and includes some fruits and vegetables for fiber because carbs give you energy; protein and fat slow digestion of food to keep blood sugar from spiking, and fiber can keep your digestive system working properly,” she says.
Have your big meal earlier in the day
If you’re committed to one big meal, try serving your big holiday meal earlier in the day so that your body has enough time to digest before bed. “If you’re eating a lot of food and your digestive system is doing a lot of work, if you’re drinking a lot of alcohol, you’re probably going to have trouble sleeping when it’s time to get to sleep,” Bryne says. “Because you might be really bloated, or really gassy, or your stomach might feel distended. Try making the meal a little bit earlier so that you have a few hours to digest before you go to sleep.”
But don’t blame a midday meal for the infamous afternoon dip. Instead, look to your circadian rhythms, aka the internal clock telling your body when to feel sleepy and when to be alert. For many of us, it dips in the afternoon, causing you to feel sleepy and not as alert. “Studies that evaluate food comas test this in the context of mid-day intakes, and mid-afternoon is a period of known reduced alertness from a circadian rhythms standpoint,” St-Onge says.
Stay hydrated
Dehydration can make you feel tired and less focused, so drink plenty of fluids, such as water and herbal tea, throughout the day. “Staying hydrated can help you drink less alcohol and slow the effects of alcohol,” Byrne says. Plus, drinking water and other beverages helps your body digest food, according to the Mayo Clinic.
Avoid or limit alcohol
Alcohol can also make you tired, so it’s best to avoid it or limit your consumption, “especially if you’re drinking more than one or two drinks,” Byrne says.
Go for a walk after eating
“I love the idea of going for a walk after eating because that forces blood flow back to the rest of the body. It can also help with digestion in general,” Bryne says. “It can also help regulate your blood sugar so that you’re not having such a blood sugar spike and then crash, and that crash would make you tired.”
Take a nap
Or, give in and take a nap, suggests Dr. Elena Ivanina, a gastroenterologist in New York City. A small 2015 study also suggests that bright light exposure after lunch may provide benefits similar to a nap. Participants who were able to take a nap or get bright light exposure after lunch were less fatigued and better at task-switching.
Try caffeine
Opinions on having caffeine are mixed. On the one hand, having a caffeinated beverage will leave you feeling energized and more alert, per the Mayo Clinic. It could help counteract the effects of a food coma. If you have the time, you could even try a coffee nap.
On the other hand, St-Onge says she would not recommend caffeine due to potential adverse influence on nighttime sleep. If you are going to have caffeine, be thoughtful about the timing of your caffeine intake: Its effects can linger in your body for up to six hours, according to the NLM.
Get enough sleep
If you go into a meal feeling tired, you’ll only feel more tired at the end. “The best advice is to get adequate sleep during the night to avoid feeling excessively sleepy during the day,” St-Onge says. The best path toward being well-rested is to stick to a schedule with the same bedtime and wake-up time each day.
When to see a doctor
Experts agree that experiencing sleepiness after eating is normal. But if food coma symptoms persist for a few days or are interfering with your routine or daily functioning, it might be time to seek out a medical professional.
St-Onge says that excessive day-time sleepiness should be taken seriously, as it could point to some nighttime sleep disorders. “Obstructive sleep apnea is often associated with excessive daytime sleepiness and should be evaluated and treated. Excessive wake at night (chronic insomnia) could also lead to daytime sleepiness. If individuals experience sleep attacks randomly throughout the day, this could indicate narcolepsy,” St-Onge says. “Other symptoms include cataplexy (loss of muscle control), sleep paralysis, and hallucinations. Individuals should seek diagnosis and treatment for these conditions from a healthcare provider.”
“I don’t think having a ‘food coma’ is a reason to reach out to a doctor, but some symptoms of a food coma could be reasons to seek a doctor. Like if you’re having really distracting digestive issues, feeling really bloated all or most of the time, or [suffering gastrointestinal issues] for more than a few days,” Bryne says. “It probably means that something else is going on, not just that you ate a bunch of food or a certain type of food in one sitting and are feeling bad; it’s that there’s another underlying problem.”
What to know about diabetes and postprandial somnolence
It’s not just overeating or having rich foods that can lead to postprandial somnolence.
“There could be an issue with insulin and sugar regulation causing low blood sugar after a meal that can cause somnolence,” Ivanina says. Out-of-whack blood sugar is a potential sign of diabetes, so this merits a check-in with your physician.
“If you’re eating a really big meal and you take insulin, you’re probably going to have a hard time. It’s not going to be your usual dose; you’ll probably be adjusting the amount of insulin, probably taking more because you’re eating more carbs, so it’s possible that you might overestimate the amount of insulin you need which would then lead your blood sugar to go too low,” Bryne says. “Low blood sugar, in general, can lead to fatigue. Eating regularly is something that’s more important when you have diabetes to ensure that you have a healthy insulin response.”
The key to controlling a food coma
There is no conclusive evidence as to what causes food comas, but it’s worth paying attention to the different factors at play and how you feel after eating to get a sense of what might be driving your own food coma.
More modest portions are the top-recommended strategy to avoid a food coma, so aim to eat smaller meals more frequently whenever possible.
The good news is that there’s no need to eliminate beloved foods entirely; instead, strive to eat them in moderation and balance them out with options full of fiber, like veggies and whole grains. Stay hydrated, maintain good sleep and activity habits, and, most importantly, listen to your body.
With additional reporting by Madeleine Burry
