Key takeaways:
The types of foods you eat — and when and how much you eat — can affect how sleepy you feel after a meal.
It’s common to feel tired after eating, and it often isn’t cause for concern. But in some cases, feeling tired after eating could be caused by an underlying medical condition.
To avoid getting sleepy after eating, try having smaller meals, limiting high-carbohydrate and high-fat foods, being physically active, and avoiding alcohol.
Food is supposed to give you energy. So why do you sometimes feel tired after eating?
Feeling sleepy after eating could just be a sign that your body is working to digest your food. But in some cases, it could be related to an underlying health condition, such as problems with your blood sugar regulation. Let’s take a look at some of the reasons you may feel tired after eating — and what you can do about it.
Why do I get tired after I eat?
Scientists are still learning exactly why eating can make people feel sleepy.
One theory was that eating diverts blood toward your digestive system and away from your brain, leading to sleepiness. But research hasn’t consistently supported this idea. Other studies suggest that eating food triggers the release of hormones that affect your brain’s sleep and wakefulness centers.
Despite some uncertainty about the exact cause, feeling tired after eating is a real and common phenomenon.
Potential causes of fatigue after eating
Below are some of the most common reasons for postmeal fatigue.
1. What you’re eating
Eating meals of any type can lead to sleepiness. But certain types of foods are more likely to make you feel sleepy than others, including:
Carbohydrate-heavy foods: Foods high in carbohydrates include pasta, bread, and white rice, as well as potato chips and pastries.
Fatty foods: Examples of foods high in fat are fried foods, red meat, and items made with heavy cream or butter.
Foods containing melatonin: Eggs, pistachios, and tart cherries are some of the foods especially high in melatonin, the sleep-regulating hormone.
2. Larger meals
It’s common to feel sleepy after eating a large meal. But there aren’t a lot of high-quality, human studies looking specifically at meal size as a trigger for food-related sleepiness.
One fruit fly study found a clear connection between meal size and sleepiness. The bigger the meal, the more the flies slept after eating.
3. Timing of meals
Your body has a circadian rhythm that controls your sleep-wake cycle. It helps you nod off to sleep at night, and also causes a dip in alertness in the middle of the day. Many people call this drop in energy an “afternoon slump.”
This energy dip happens at different times for different people, but it’s often sometime between 1 p.m. and 4 p.m. So, if you’ve noticed that lunch is the meal that has you reaching for a pillow, your body’s circadian rhythm may also be playing a role.
Read more like this
Explore these related articles, suggested for readers like you.
4. Alcohol with meals
Alcohol is known to cause sleepiness. Drinking alcohol along with a meal is likely to make you feel tired after eating. And if you combine alcohol with some of the factors mentioned above — such as eating a carbohydrate-heavy meal in the afternoon — you’re just about guaranteed to find yourself ready for a nap.
5. Low blood sugar
People often talk about a “sugar crash” after eating. But for most healthy people, the body is able to tightly regulate blood sugar levels by releasing just the right amount of insulin during and after a meal. As a result, a dramatic drop in blood sugar after eating is uncommon.
But some people with underlying health conditions do experience a true drop in blood sugar after meals. This is known as reactive hypoglycemia, or postprandial hypoglycemia. It occurs about 2 to 5 hours after a meal, and can cause sleepiness. This differs from typical postmeal sleepiness, which usually occurs 30 to 60 minutes after a meal.
Sleepiness caused by postprandial hypoglycemia often occurs along with symptoms, such as:
Shakiness
Sweating
Heart palpitations
Confusion
Postprandial hypoglycemia is more common in people who have:
Thyroid or other hormone problems
6. Insulin resistance
Insulin resistance may make you feel tired after eating, especially after a big meal. Insulin is a hormone that helps move glucose from your bloodstream into your cells, where it’s used for energy. When your cells become less responsive to insulin, glucose can build up in the blood instead of being used efficiently by the body.
Insulin resistance is common in people with prediabetes and Type 2 diabetes. But it can also occur before diabetes develops. Other factors that may increase the risk of insulin resistance include:
Physical inactivity
Having a body mass index (BMI) over 30
7. Underlying health conditions
Sometimes, feeling tired after eating has less to do with food and more to do with an underlying health condition. Several conditions can cause ongoing tiredness and make you more likely to feel sleepy after meals, including:
How to stop feeling tired after eating
Postmeal sleepiness can come at the worst times — just before a work presentation or right before the drive home. The good news is that there are things you can do to keep your energy levels up and prevent sleepiness after eating.
To avoid feeling tired and sluggish, try to:
Eat a balanced diet that includes nutrient-rich foods that can increase your energy.
Eat smaller meals more frequently throughout the day instead of large meals.
Limit or avoid alcohol.
Try to get enough high-quality sleep.
Make time for daily physical activity.
Spend time outdoors in sunlight.
When to get help for fatigue
Feeling sleepy after a big meal is often nothing to worry about. But if you need to take a nap after most meals, or you feel tired all the time, it’s best to connect with a healthcare professional. They can help you figure out whether an underlying health condition might be contributing to your fatigue.
Frequently asked questions
There’s no single best vitamin for fatigue because the cause can vary. If the fatigue is the result of a nutrient deficiency, correcting that deficiency with supplementation can improve energy levels. Common nutrient deficiencies linked to fatigue include iron, folate, and vitamin B12. But fatigue can also be caused by poor sleep, stress, diet, or medical conditions. In these cases, taking extra vitamins is unlikely to increase your energy levels. If you have persistent fatigue, it’s a good idea to see a healthcare professional who can help pinpoint the cause and recommend the right treatment.
Prediabetes often doesn’t cause any symptoms. Many people feel completely normal and only realize they have it when they get routine blood work done. When symptoms do occur, they can include feeling more tired than usual, increased thirst, having to pee a lot, and weight loss. Some people experience a skin condition called acanthosis nigricans. This often looks like a thick, dark patch of skin on certain areas of the body such as the back of the neck, armpit, groin, or face.
There’s no single best vitamin for fatigue because the cause can vary. If the fatigue is the result of a nutrient deficiency, correcting that deficiency with supplementation can improve energy levels. Common nutrient deficiencies linked to fatigue include iron, folate, and vitamin B12. But fatigue can also be caused by poor sleep, stress, diet, or medical conditions. In these cases, taking extra vitamins is unlikely to increase your energy levels. If you have persistent fatigue, it’s a good idea to see a healthcare professional who can help pinpoint the cause and recommend the right treatment.
Prediabetes often doesn’t cause any symptoms. Many people feel completely normal and only realize they have it when they get routine blood work done. When symptoms do occur, they can include feeling more tired than usual, increased thirst, having to pee a lot, and weight loss. Some people experience a skin condition called acanthosis nigricans. This often looks like a thick, dark patch of skin on certain areas of the body such as the back of the neck, armpit, groin, or face.
The bottom line
It’s normal to feel a little drowsy after eating, but frequent or severe postmeal sleepiness can sometimes point to an underlying health issue. Paying attention to what, when, and how much you eat may help keep your energy up. And if your “food coma” is becoming a daily event, a healthcare professional can help you figure out why.
Why trust our experts?
References
Altuntas, Y. (2019). Postprandial reactive hypoglycemia. Şişli Etfal Hastanesi Tip Bülteni.
American Academy of Dermatology Association. (n.d.). Acanthosis nigricans: Signs and symptoms.
Bazar, K. A., et al. (2004). Debunking a myth: Neurohormonal and vagal modulation of sleep centers, not redistribution of blood flow, may account for postprandial somnolence. Medical Hypotheses.
Cunliffe, A., et al. (1997). Post-prandial changes in measures of fatigue: Effect of a mixed or a pure carbohydrate or pure fat meal. European Journal of Clinical Nutrition.
Eicke, B. M., et al. (2003). Volume flow in the common carotid artery does not decrease postprandially. Journal of Neuroimaging.
Kvietys, P. R. (2010). Chapter 5: Postprandial hyperemia. The Gastrointestinal Circulation.
Murphy, K. R., et al. (2016). Postprandial sleep mechanics in Drosophila. eLife.
Orr, W. C., et al. (1997). Meal composition and its effect on postprandial sleepiness. Physiology & Behavior.
Slama, H., et al. (2015). Afternoon nap and bright light exposure improve cognitive flexibility post lunch. PloS One.
Stahl, M. L., et al. (1983). Postprandial sleepiness: Objective documentation via polysomnography. Sleep.
Wells, A. S., et al. (1997). Influences of fat and carbohydrate on postprandial sleepiness, mood, and hormones. Physiology & Behavior.
