Here’s Why You’re Sleepy After Lunch

If you feel tired after meals, don’t be alarmed: Postprandial somnolence is totally normal, if irksome. Here are some ways to feel more alert after meals.

Boy falls asleep on a sandwich. He is tired and has put his head on the sandwich. He played too much with his phone and fell asleep.
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Have you ever felt an overwhelming need to take a nap as soon as you’re done eating a meal? We’ve all been there, ready for a nap after that extra helping of turkey and mashed potatoes at Thanksgiving. But sometimes, even eating a sandwich can make someone want to curl up under the desk for a snooze.

As strange as the post-meal nap urge can be, it turns out that getting sleepy after lunch is totally normal, with scientific reasoning behind it. But if the sluggishness makes you anxious or embarrassed, or gets in the way of your productivity, there are steps you can take to mitigate the intensity of the post-lunch dip and improve how you feel after eating.

Why do you feel tired after eating?

As strange as it may be, feeling drowsy after a meal is normal. The scientific term for experiencing tiredness after eating is called postprandial somnolence. Postprandial somnolence is influenced by a variety of factors, including our circadian rhythms, which is why we naturally feel a post-lunch dip.

“After lunch, we experience a natural lull in wakefulness that often leads people to feel sleepy after they eat,” says Dr. Chris Winter, neurologist, advisor to, and author of “The Rested Child.” “It represents a crossroads in the mechanisms that help us feel awake.” Ideally, Winter explains, our energy levels should be rising throughout the day. Your sleep drive dictates that the longer you’re awake, the more you need to sleep, which pushes energy levels down. Alerting signals, such as sunlight or a light walk, push back against your need to sleep, and help increase energy levels.

Winter says that insulin changes can also affect sleepiness. After you eat a meal, your blood sugar rises, and insulin is released into the bloodstream, suppressing a specific neurotransmitter and making you tired. “Insulin spikes can reduce orexin production. Orexin is the neurotransmitter missing in narcolepsy, which makes people feel constantly sleepy. Big meals can drop our orexin levels, making us feel temporarily sleepy.” This can happen with any meal, but is particularly noticeable after eating too many carbohydrates, which can cause a spike in blood sugar that provides a temporary surge of energy followed by a crash, leading to feelings of tiredness.

Eating also releases serotonin, a neurotransmitter and hormone that helps regulate sleep and appetite, mediate moods, and inhibit pain. When we eat foods rich in tryptophan, an essential amino acid found in protein-dense foods such as turkey, chicken, fish, eggs, and chickpeas, it stimulates serotonin production. So, some researchers believe that people may feel more tired after eating because their body is producing more serotonin. There’s also evidence to suggest that even the anticipation of eating can trigger our body to release serotonin, which can impact how we feel after a meal.

What should I do to avoid falling asleep after eating?

Get a good night’s sleep

Sleeping well and long enough fully resets your sleep drive and helps regulate your circadian rhythms. “The dip is always going to be there, but being more fully rested is always going to be helpful when compared to not being well-rested,” Winter says.

Take time to focus on eating

Giving yourself dedicated time to mindfully eat your lunch allows you to stay connected to your body and listen to your body’s signals and fullness cues. Elise Museles, a certified eating psychology and nutrition expert, and the author of “Food Story: Rewrite the Way You Live, Think & Eat,” says that many of us engage in what she calls “we eat and” during lunch. “We eat and we scroll, answer emails, watch the news, run out the door. When we can just eat — and it doesn’t have to be a whole sit-down experience — you’re more relaxed and noticing how food feels in your body. You can’t do it when you’re multitasking.”

Stay active

After eating lunch, get moving to aid digestion and keep energy levels up. This can also help with glycemic control. Go for a 5- to 10-minute walk outside, or even take a couple laps around your office.

Seek light

Exposure to natural daylight (a very bright white-blue light) and sunlight (white light) helps to regulate our circadian rhythms and promote wakefulness and alertness. A study exploring the effects of light intervention on alertness and mental performance during the post-lunch dip concluded that both blue-enriched and red-saturated white lights had more efficient stimulating effects on modulating the brain activities associated with daytime alertness than the dim and normal indoor light conditions during the post-lunch dip hours. Try eating lunch outside or by a window with plenty of natural light, or go for a light walk outside afterward.

Properly space out meals

Besides avoiding eating larger meals, which take more energy to digest and can leave you feeling sluggish, don’t wait too long to eat in between meals. Museles recommends checking out your eating rhythm — how long it takes to get hungry in between meals — to determine your hunger levels and how frequently you need to eat. Consider having a well-balanced snack to keep your blood sugar levels steady and tide you over until the next meal.

What foods should I eat to avoid feeling tired after lunch?

Eat balanced meals & snacks

Eating causes your blood sugar levels to rise, which can lead to a decrease in energy. After you eat a meal, insulin unlocks sugar into the bloodstream. But you want to make sure that you’re eating meals that are more balanced, so you won’t have that spike,” Museles explains.

To stabilize blood sugar and sustain your energy levels throughout the day, Museles recommends including the following four macronutrients on your plate, and offers suggested sources for each:

  • Healthy fats: nuts, flaxseed, avocados, and salmon
  • Fiber: lentils, beans, and vegetables such as alliums (leeks, garlic, onions), artichokes and asparagus
  • Complex carbohydrates: whole grains, legumes, fruits, and both starchy and non-starchy vegetables
  • Protein: fish, eggs, chicken, turkey, legumes, dairy products

For snacks, incorporate the same macronutrient balance, just in a smaller quantity. For example, you can try including vegetables, nuts, and in-season fruit, or a protein shake with fruits or veggies and flaxseed or nut butter, such as those used in these afternoon snacks for an energy boost.

Don’t overdo the carbs

“If you have too many carbohydrates, it does affect your blood sugar, and causes a spike. Imagine drinking caffeine: You feel a charge of energy and then a crash,” Museles says. “The same thing happens when you have carbohydrates without anything that’s going to slow down absorption of glucose.” Since carbohydrates turn to glucose, ensuring that you have a balanced plate that also incorporates healthy fats and protein (plant-based sources count, too) can help your blood sugar stay more regulated and help you to feel less fatigued.

Avoid eating big meals

“Bigger meals are more likely to make you feel sluggish because your body is working harder to digest that meal,” Museles says. That’s not to say that you can’t have a larger meal, like at Thanksgiving, for example. But having an awareness that a larger meal will take longer to digest, and that feeling more tired is a normal response, can help alleviate concerns and help you plan accordingly, like making time for a light walk afterward.

Stay hydrated

“Hydration is a huge part of energy and fatigue. We might think we’re hungry, and we might be, but we also could be dehydrated,” Museles says. “If you’re feeling fatigued, think about if you’ve had enough water during the day. Or if you’ve exercised, have you made sure you had a bit of electrolyte replacement?” Museles suggests adding fresh lemon or a bit of sea salt to your water to supply natural electrolytes to aid replenishment. In addition to drinking enough water, she also recommends reaching for fruits and vegetables with high water content to keep hydration levels stable. Examples of seasonal produce with high water content include watermelon, strawberries, cucumbers, and tomatoes in the summer, and carrots, leafy greens, and citrus in fall and early winter.

Is feeling tired after eating normal?

“Feeling tired after eating is very normal,” Winter says. “Some cultures feel it's so normal, they institute siestas!” But if you’re still experiencing excessive tiredness after eating, even after making tweaks to your lunch routine, it could be time to consult a health care professional. In addition to seeking medical advice, Museles says that it can also be helpful to examine your family health history to see if there is a pattern of illnesses — such as diabetes, hypoglycemia, anemia, or thyroid issues — that might explain why you feel fatigued after eating.

Feeling tired after a meal is normal. But the effects of the post-lunch dip can be lessened by eating well-balanced meals to sustain stable blood sugar and energy levels throughout the day, keeping hydrated, seeking out light, and staying active.