Last Updated on October 1, 2023 by Louise Carter
While people joke about falling into a “food coma,” the scientific term is postprandial somnolence, loosely translated from the original Latin as “sleepiness after eating.”
While it’s tempting to nap immediately after a meal, stay awake and active for at least 2 hours.
This enables the body to process food and start burning calories. Immediately sleeping after food can lead to indigestion, acid reflux, and weight gain.
Overeating diverts blood flow from the brain toward the intestines to begin processing what you’ve consumed, while the body experiences a mid-afternoon energy slump.
The food you eat for lunch will also influence your tiredness level after a meal.
Foods high in simple carbs cause a blood sugar spike. If you pair carbs with foods high in tryptophan, the brain will release the hormones serotonin and melatonin, which are essential for sleep.
Removing the foods that trigger sleepiness means you won’t need a post-lunch nap. If you feel drowsy, hydrate, exercise, and turn up the lights to influence your circadian rhythms and sharpen your senses.
Why Do I Need a Nap After Eating?
It’s common to feel sluggish after eating a large meal while the body is digesting food. You may be tempted to nap after lunch if you have a free afternoon.
What causes fatigue after eating lunch? Here are the most likely explanations:
Excessive Food Consumption
Eating a large meal is linked with feeling drowsy and tired. Social occasions that revolve around a feast, like Thanksgiving, often leave everyone sleepy after eating.
Part of the explanation for this is psychological and instinctual. Our Neanderthal ancestors didn’t have a reliable eating routine, lacking 3 scheduled meals a day.
As they didn’t know when they’d next eat, they’d overeat when food was available and sleep off the negative effects so they had sufficient energy to hunt their next meal.
While we no longer need to hunt and gather food in the 21st Century, the instinct remains.
Postprandial somnolence after a large meal can also be explained by its impact on the body. The more food we consume, the harder the digestive system needs to work.
The body diverts resources to the digestive system, especially the small intestine. According to Clinical Physiology and Functional Imaging, blood is redirected from the brain, leading to sleepiness.
The body’s circadian rhythms influence energy levels throughout the day.
If you wake up in the morning when the sun rises and head to bed at night after sunset, you’ll likely experience a mid-afternoon energy slump.
The Journal of Sleep Research believes that the energy crash results from your body temperature dropping slightly. This isn’t a conscious choice, as the body reacts to circadian rhythms.
Your body and brain will connect this drop in temperature to sleepiness.
If you’ve recently eaten lunch, especially a hearty meal, postprandial somnolence will also play a part. Your instincts will tell you it’s time to nap, even if it’s impossible.
Eating a light breakfast and lunch, rather than skipping the first meal of the day and compensating for it later, can help minimize this sharp energy depletion.
High Carbohydrate Meals
Foods high in simple carbs, like processed meals that contain corn syrup, are high on the glycemic index. They’ll raise your blood sugar before it drops away, leading to sleepiness and sluggishness.
The body breaks down carbohydrates into glucose, a fuel that provides energy. Simple carbs break down much faster than most macronutrients, and glucose enters the bloodstream almost immediately.
The body reacts by releasing insulin from the pancreas. Insulin instructs the liver and muscles to absorb this glucose. This leads to postprandial reactive hypoglycemia, where your blood sugar levels drop.
Not all carbohydrates are bad. Carbs, protein, and fat are macronutrients the body needs to function. Focus more on ingesting complex carbohydrates, especially at lunchtime.
Examples of complex carbs are brown rice, vegetables, and quinoa. These foods take longer to break down and release a steadier energy flow, meaning you’re less likely to feel sleepy after eating.
Is Falling Asleep After Eating A Sign of Diabetes?
Carbohydrates are linked to type 2 diabetes. Anybody can feel tired after eating too many simple carbs, so don’t conclude you’re pre-diabetic. Here are the main symptoms:
- Unexplained weight loss.
- Feeling thirsty all the time.
- Frequent urination (nocturia.)
- Blurry vision.
- Slow healing of cuts and wounds.
- Feelings of numbness in the hands and feet.
If you take early action, you may be able to avoid developing type 2 diabetes.
Foods High in Tryptophan
Tryptophan is an amino acid in certain foods, like turkey, fresh fish, nuts, and cottage cheese.
According to the International Journal of Tryptophan Research, tryptophan encourages the brain to produce serotonin.
Serotonin is a chemical messenger in the brain that regulates mood, most notably feelings of contentment and relaxation.
This is why serotonin is often called “the happiness hormone.” It’s a precursor to the production of the sleep hormone melatonin.
If the brain releases serotonin after a tryptophan-rich meal, you’ll experience an increase in melatonin, especially in a dark room. The additional melatonin leads to sleepiness.
Is Napping After Eating Healthy?
It’s natural to feel sleepy after eating, especially post-lunch, but is it a good idea to nap? If you have no other responsibilities, a brief rest will be appealing.
Giving in to the temptation to nap straight after eating is inadvisable.
Your body needs the opportunity to process the meal before lying down, as immediately taking a horizontal position can lead to heartburn and acid reflux.
Can I take a 20-minute nap after eating? Yes, but a longer sleep leads to sleep inertia and foggy thinking.
How Long Should I Wait To Take A Nap After Eating?
If you can keep your eyes open after eating, try to do so for at least 2-3 hours. This will give the body sufficient time to carry out the digestive process.
This will likely tie in with most people’s routine during a 9-to-5 working day.
If you eat at lunchtime and experience an energy slump, the passing of 3 hours will likely coincide with the end of your shift. After this, your time is your own.
Be careful about immediately seizing the opportunity to nap once this time has passed. If you enter a deep sleep a few hours before bedtime, you may struggle to sleep at night.
Usually, the immediate sluggishness and exhaustion of postprandial somnolence will have passed. You’ll likely experience a second wind and feel ready to tackle the remainder of the day.
Does Taking a Nap After Lunch Make You Fat?
If you regularly consume more calories than you burn, you’ll gain weight, regardless of whether you nap. However, napping immediately after eating can lead to faster weight gain.
While the human body burns calories while we sleep, the process is much slower than when awake.
If you rest for 30 minutes straight after eating, you may burn around 25 calories. Just sitting upright can burn twice as many calories in the same timeframe.
If you ate a 100g chicken salad, a banana, and a low-fat yogurt for lunch.
This is about 200 calories. Staying awake for 2 hours, even if you’re primarily inactive, will cancel out the calorie count of your lunch. Taking a nap will leave you with a deficit of around 100 calories.
This issue becomes more prevalent if you eat a larger, less health-conscious lunch. If your lunch has 700 calories, a 30-minute nap will burn less than 5% of the calories.
Is It Better To Walk or Nap After Eating?
Get some light exercise if you’re serious about burning calories after eating. For example, 30 minutes of walking can burn off almost 200 calories.
Stepping outside and into the sunshine can reset your circadian rhythms, which can combat the afternoon energy lull that can otherwise feel inevitable.
Sports Medicine also builds upon the previous explanation of how breaking up sedentary periods can bolster health, as physical movement manages glucose levels and reduces blood pressure.
A light stroll can work wonders for your health and reduce the risk of weight gain.
How To Stop Feeling Tired After Eating
The best ways to retain balanced energy levels during the day include:
- Eat smaller meals with greater frequency.
- Turn up the lights in your home or office. PLoS One stated that lighting increases wakefulness.
- Get some light exercise, even if it is just a short, brisk walk around the block.
- Drink water because dehydration leads to sleepiness and foggy thinking.
- Avoid trigger foods likely to cause fatigue, like simple carbs.
A reliable sleep pattern and eating at the right times help avoid sleepiness. Industrial Health explains how night shift workers who eat in the evening struggle with wakefulness and performance.
Where possible, resist the urge to take a nap straight after eating. The longer you stay awake and active, the more calories your body will burn and the more comfortable you feel when lying down.