Raise your hand if you’ve ever experienced a wave of exhaustion or feeling of drowsiness sometimes accompanied by the sensation of being unpleasantly, uncomfortably full after eating. When you’re in this state, even the effort to get to the couch may feel taxing.
If you’re talking with friends and family, you’ll probably call it what it feels like: a food coma. Some also call it an after dinner dip, the itis, but experts refer to this sensation as postprandial somnolence or postprandial fatigue.
And yes, it’s a real, diagnosable sensation. Read on to find out why food comas occur — and what steps you can take to prevent them.
What is a food coma?
You’re far from alone if you’ve had a food coma. They’re very common, particularly on holidays like Thanksgiving, where eating is often a day-long event, beginning with snacks, leading into a big meal of many different dishes, and ending with multiple varieties of pie. Those many options can lead to eating more than usual.
They can also occur as the result of more everyday eating habits — although you probably don’t want to experience food coma every day.
“Food comas are something most everyone has experienced,” says Dena Champion, a registered dietician nutritionist at The Ohio State University Wexner Medical Center. And if they occur rarely, and after a large or indulgent meal, they’re not typically a big concern.
Here’s the good news about postprandial somnolence: While the sensation may be unpleasant, it’s relatively fleeting.
Typically, it’ll pass within a few hours — or even faster, says Dr. Alicia Shelly, an expert at Health Testing Centers. And if you end up going straight to bed, you should feel better upon waking the next day.
If you’re not sure whether or not you’re experiencing food coma, read on for symptoms, potential causes, and ways to alleviate the feeling.
Food coma symptoms
Food comas typically result in a person feeling drowsy or fatigued. Some people also feel bloated, sluggish, or less alert, and may also be distinctly uninterested in being active, Champion notes.
What causes food comas?
Theories abound, along with some misunderstanding about why people tend to feel sleepy after eating. The most likely culprit is what you eat — and how much of it.
But from a scientific perspective, the known reason isn’t nailed down, which can lead to “some controversy,” says Dr. Elena Ivanina, DO, gastroenterologist, Lenox Hill Hospital, New York City. “There is no clear cause of postprandial somnolence, but a few hypotheses,” Ivanina says.
Here are likely reasons for why you experience a food coma — along with some popular theories that may not hold water.
High-fat or simple carbohydrate meals
Another potential cause of post-meal sleepiness: a high-fat meal, full of creamy sauces, fried foods, butter, and oil, Champion says.
Other food groups may also be involved. “Carbohydrates can increase that food sleepiness,” Shelly notes. A meal that centers simple carbs (like white pasta) could lead to a crash later on.
“Alcohol can also contribute to that sluggish feeling post-meals,” Champion says. That’s for two reasons: alcohol’s sedative effect, and it’s inhibition-lowering quality, which could make you eat more, and also more indulgently, she says.
Larger-than-usual portion size
Along with what you consume at your meal, how much you eat matters, too.
“Research suggests ingestion of a large meal leads to postprandial fatigue,” Champion says.
For example, one small 2018 study looked at the eating patterns of truckers in Brazil and found an association between what truckers ate and their sleepiness — study participants who ate a “prudent” diet (as opposed to a traditional or Western meals) were less sleepy.
Animal research — specifically, a study involving fruit flies — indicates a correlation between sleepiness after eating and the amount consumed. The study also found a link between postprandial somnolence and protein-rich and salty foods. But of course, this research involves fruit flies, not humans, so whether or not these same results translate to our eating habits is unknown.
More studies are needed to determine if the size of the meal is a decisive factor in causing food comas.
Your digestive system getting to work
Eating can also turn on your parasympathetic nervous system aka the rest-and-digest system within your body, Ivanina notes. With it activated, your heart rate slows down and your digestive system gets to work. This could lead to an increase in sleepiness.
If you’ve heard that during digestion, blood is diverted from your brain and to your stomach, making you less alert, don’t be alarmed. “It used to be believed that food comas were caused by redistribution of blood after a meal from the brain to the gut,” Ivanina says. But that’s unlikely, since the flow of blood to the brain is “preferentially maintained,” she says.
Timing of your meals
Many people experience the infamous afternoon dip, with energy plummeting after their midday meal. But don’t blame lunch.
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.
Likely myth: Foods with tryptophan
Call this one the turkey theory, since the centerpiece of the Thanksgiving meal, is famous for containing tryptophan, an amino acid.
When you eat foods high in tryptophan, it ups your melatonin levels, Ivanina explains. That matters, since your levels of this naturally occurring hormone rise in the evening, helping to prime your body for sleep by getting it into a relaxed state, per Johns Hopkins Medicine.
Still, there’s good reason to feel skeptical about this theory. Many of us have experienced a food coma after Thanksgiving when turkey is the main meal. But 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
“If you have already over indulged and are feeling sluggish, you may have a hard time feeling more energetic quickly,” Champion notes. That is, there’s not much you can do to treat a food coma once it hits — you might just need to wait it out.
Hydrating yourself by drinking fluids can help, as can going for a short walk, she says. Or, give in and take a nap, Ivanina suggests. A small 2015 study also suggests that bright light exposure after lunch may provide similar benefits 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.
But with so few methods available to immediately ease the discomfort, your best bet is to learn to ward off a food coma.
Try these tips if you need to keep up your energy and suspect you may succumb to food coma symptoms after a certain meal.
Watch portion size
“The most important things you can do to prevent this from happening are to eat smaller meals and possibly meals lower in fat,” Champion says.
Here, a few of Champion’s recommended strategies to avoid a food coma:
- Slow down: Chew your food completely and enjoy the tastes, smells, and textures.
- Assess your hunger: When you start to feel full, take a few breaths and pause to see if you’re satiated.
- Don’t go in hungry: “Don’t skip meals all day in preparation for a large feast. This often leads to eating to the point of discomfort,” Champion cautions.
Eat a balanced ratio of fat, carbs, and fiber
At a celebratory meal or big family gathering, you may not want to cut out all high-fat foods. “If you are going to eat rich foods, enjoy them, but try pairing them with lighter foods like fruits and vegetables,” Champion says.
At Thanksgiving, that may mean serving yourself creamy mashed potatoes and luscious gravy, but also devoting some dish real estate to a side salad or roasted veggies.
For more everyday meals, try to make swaps. For instance, opt for baked fish rather than fried, Champion suggests. Or, serve fried fish with roasted veggies and potatoes.
In general, a meal made up of high-fiber foods with lean protein makes it less likely you’ll feel sleepy afterward, Champion says. “Think veggies, whole grains, and tofu versus creamy alfredo pasta and bread,” she says. High-fiber foods are filling, and leave you satisfied — not exhausted, she says.
Alcohol has a sedative effect, making you feel relaxed and ready to sleep, Shelly points out. So if you want to stay alert, limit your intake of cocktails and wine, she says.
Having a caffeinated beverage will leave you feel 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.
Just 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. An after-dinner cup of joe might prevent you from getting a good night’s rest.
Get enough sleep
If you go into a meal feeling tired, you’ll only feel more tired at the end. The best path toward being well-rested is to stick to a schedule, with the same bedtime and wake-up time each day.
If you are tired after a daytime meal, consider a quick power nap, Shelly says (not too long, though, since that could interfere with your sleep schedule, she notes).
Drinking water will help you feel full, furthering your goal of avoiding excessive portions, Shelly says. Plus, drinking water and other fluids helps your body digest food, according to the Mayo Clinic.
When to see a doctor
Every expert agrees: We all experience the sleepies after eating sometimes.
But if food comas occur persistently or when you’re eating small meals, reach out to a health-care provider. “If it is happening frequently or accompanied by other symptoms such as dizziness or lightheadedness or other symptoms then it is best to discuss with your physician,” Ivanina says.
Any extreme or ongoing fatigue is something to bring up with your physician, Champion notes. Fatigue is a frequent symptom in many diseases, including depression, anemia, cancer, heart disease, and sleep apnea, according to the Mayo Clinic.
Given the seriousness — and variety — of these conditions, it’s a symptom that merits attention if you feel that it’s an on-going experience.
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.
The key to controlling food comas
With researchers divided when it comes to a cause, it’s worth trying to track what seems to drive your own food comas. “Pay attention to how you feel and decide if what you ate is worth it,” Champion recommends.
More modest portions are the top-recommended strategy to avoid a food coma. But 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.