Why You're Feeling Fatigued or Tired After Eating [+ Tips to Prevent It]

Key Takeways
Feeling tired after eating often results from the natural digestion process, which diverts energy to your gut. It can also be a sign of sharp glucose fluctuations from high-carb meals, poor sleep habits, or an underlying issue like reactive hypoglycemia.
- Post-meal fatigue can be triggered by high-glycemic foods (such as white rice and pastries) or by an inflammatory response after a large meal.
- Read on to find practical tips to maintain your energy, such as balancing meals and taking a post-meal walk.
- The Nutrisense program allows you to track your glucose data measured in interstitial fluid 24/7 and work with a dietitian to understand your bodyâs unique responses to food.
Is Post-Meal Tiredness Normal?
Do you need to lie down after a big meal? A post-meal slump is not always a cause for concern. After all, we've all felt tempted to have an afternoon nap after a heavy lunch or needed a minute before having enough energy to clear the dishes after dinner. There are even a few excellent terms for it, postprandial sleepiness, or the more commonly known, food coma!
The 2 PM Post-Lunch Slump
Itâs 1:45 PM, and you just finished lunch at your desk, hoping to feel energized for your afternoon meetings. Instead, a heavy fog rolls in. Your eyelids feel heavy, and you find yourself rereading the same email, fighting the urge for a nap. Itâs frustrating when the meal meant to power you through the day leaves you feeling drained and struggling to focus.
If this happens all the time and comes hand-in-hand with overwhelming feelings of fatigue, you may want to pay more attention to what's causing it. It's exhausting being tired all the time, especially when you're trying to be productive or meet a deadline. And if you're always tired after meals that are supposed to nourish and energize you, it can be even more frustrating.
Fatigue is often a sign from your body that something else is going on under the surface. Sometimes, it can be because of irregular sleeping patterns, but it's often because of other, less obvious reasons, such as the timing and composition of your meals, your activity levels, or your lifestyle habits before you hit the sack. Read on to discover what's causing your post-meal tiredness and what you can do about it.
Which Foods Trigger Post-Meal Fatigue?

What you choose to eat can significantly impact how energetic you feel later due to your body's response to different types of food. Significant peaks and valleys in glucose values cause postprandial fatigue, or what we know as a sugar crash.
It's essential to keep your portions small when you eat a meal filled with foods high in starchy carbohydrates - think rice, potatoes, or beans here. Smaller amounts (our dietitian Chrissy Stagg recommends 1â4 to 1â3 cup here) will help avoid a sharp rise and fall in glucose values after your meal.Â
Try to pick non-starchy vegetables in place of starchy vegetables when possible. It will help you eat a larger portion with fewer calories and a much lower impact on your glucose values.
Can Sleep Habits Cause Afternoon Slumps?
It's crucial to focus on getting enough quality sleep, too. To function properly throughout the day, we need to sleep regularly. On average, people feel most tired around midnight and early afternoon after lunchtime.
Your energy levels can vary depending on how rested you are from the night before. If you are sleep-deprived, you may feel a lot more exhausted than usual around these times. Going to sleep at or around the same time every day can help your body form a pattern to help you feel more rested and less tired during daylight hours.
Can Exercise Help After Meals?

Do you know what epinephrine and norepinephrine are? These hormones affect energy, and things like exercise and stress significantly impact them.
Your body releases these stress hormones, which energize you when you work out. So, even when you feel too tired to do it, a quick walk around the block can actually perk you right up! Also, regular exercise is a good strategy for fighting any stress or lifestyle issue that leaves you drained.
Can Digestion Itself Make You Sleepy?

Your digestive system (especially your large and small intestines) needs a large amount of energy to digest your food and drink. After a meal, your body begins to focus on digesting and processing the calories you consumed.Â
So, your brain diverts most of your body's energy towards digestion by releasing gastric hormones that increase blood flow and dilate the blood vessels that supply the digestive system.
It reduces blood flow to other parts of your body when this happens, leading to tiredness. Since your intestines spend hours working overtime to metabolize your meal, the rest of your body slows down and relaxes, making you feel tired.
Which Health Conditions Cause Fatigue After Meals?
You know what lifestyle and eating habits can cause post-meal tiredness, but those aren't the only reasons for your postprandial slump. If you're eating, sleeping, and exercising right and still feel exhausted after a meal, it could be due to one or more of these other factors:
Glucose-related Issues

Fatigue - mainly tiredness following a meal - is a common symptom of glucose issues. When glucose is too high or too low, you can experience exhaustion due to an imbalance between the amount of glucose in your blood and insulin levels.
Insulin must transport glucose out of the blood and into the cells to provide your body's cells with energy. When there is not enough insulin, or it isn't working effectively, the sugar in your blood can't get into your cells. When this happens, your cells lose the ability to perform correctly. As a result, we feel tired.
Sleep Disorders
You usually plan your sleeping schedule according to your lifestyle, including when you have to work and your school or social life. However, this doesn't always end up being the best schedule for everyone. As a result, some people may suffer from circadian rhythm sleep disorders.
It means that the relationship between your internal clock and the time where you live (when the sun rises and sets) does not line up correctly. Having a circadian rhythm sleep disorder is frustrating. It can leave you feeling tired and foggy during the day and especially after meals.
Food Allergies and Intolerances
Understanding food allergies and intolerances can be important for people who suffer from chronic fatigue. During an allergic response, your immune system uses a large amount of energy to deal with the offending food. As a result, you will see a dip in your energy levels.
Eliminating foods that cause issues and finding the alternatives that will still give your body the energy and nutrients it needs is necessary to get out of this cycle. You will find the energy to do all of the things you love and feel like you again in time. Consider working with a dietitian or someone who specializes in food allergies to identify if this is a cause of your post-meal fatigue.
Gut Dysbiosis and Inflammation

No one feels super energetic when they're unwell, but there's a little more to it than that. A commonly held view is that viral or bacterial infections may impair your immune system.
With over 80 percent of the immune system housed in your intestine, researchers are now looking for a link between gut dysbiosis (an imbalance of gut microbiota) and the development of chronic fatigue.
Newer research studies have shown that the microbiome of people who have chronic fatigue syndrome is different from that of those who do not suffer from this disorder. By maintaining optimal microbiome integrity, you can improve your immune system to help prevent fatigue.
How To Prevent Post-Meal Fatigue
Whatever the reasons are, feeling tired after every meal can be frustrating. Apart from addressing the underlying issues, you can do a few things to prevent that post-meal slump. Here are a few tips to help you get started:
Walk After Meals

A short walk outside can work wonders after a large lunch. Activity after eating can play a significant role in reducing the gastric emptying time by reducing the time that food moves through the gastrointestinal tract. So by moving your body, you're helping things move within your gut and improve digestion.
Drink More Fluids
Water is essential for carrying nutrients to your cells and expelling waste. Over half of your body weight is water, and you constantly lose a certain amount of water throughout the day. When you are low on fluids, your body may feel tired and weaker than usual.
So, it's essential to consume sufficient fluids in beverages and water-filled food such as fruits, vegetables, and soup. It will help replenish the water your body loses throughout the day and can help you maintain your energy.
Limit Caffeine And Alcohol Consumption

At first, consuming caffeine can improve mood and reaction times in some. But some people who consume caffeine regularly develop tolerance, so having the same amount of caffeine will not produce the same positive effects over time.
Alcohol intake, too, can make you feel quite tired. It's a depressant and can contribute to low energy, but it can also be a stimulant a few hours after consumption. It then disrupts sleep and causes fatigue the following day. Eliminating a nightly drink to fall asleep or not overindulging on the weekend may improve your energy considerably.
Balance Meals
Since poor nutrition plays a significant role in causing fatigue, balancing your meals with energy-boosting foods may be helpful. A healthy balance of all the main components - fruits and vegetables, healthy fats, and protein can be an excellent way to help combat tiredness in the long term. When combined with eating regularly, you can keep your glucose levels steady for longer periods, which keeps tiredness at bay.
Dim Lights Before Bed
Light levels and wavelengths are essential factors for healthy, restful sleep. Your bedroom should be completely dark because brighter light levels may suppress melatonin.
This hormone provides your body's internal biological signal of darkness. Blue light can suppress melatonin, and LED lights, while being more energy-efficient, tend to produce more blue light. Using dim or red lights before bedtime may help you sleep better.
Bright Light In Daytime

Bright morning light will shift the time for sleep earlier, so you will tend to get sleepy and fall asleep earlier in the evening and wake up earlier in the morning.
If you cannot wake up early enough, go into a brightly lit area when you get up (for example, eat your breakfast outside or next to a sunny window). Exposure to bright light throughout the day can have positive effects, including boosting alertness and mood. So, try to allow natural light into your room whenever possible.
Prioritize Gut Health
When the gut microbiome is compromised, energy and fatigue concerns may develop, so it's crucial to take care of your gut. Healthy gut bacteria help create B-vitamins and neurotransmitters like serotonin and tryptophan, the chemicals in the brain and the body responsible for happiness, motivation, and sleep.
Fermented foods such as sauerkraut, kimchi, tempeh, and pickles can be beneficial, along with a high-quality probiotic, in helping to ensure healthy populations of good bacteria in the gut.
Adjust Meal Timing
Many people find it effective to alter the timing of meals and snacks. For some, getting in several small meals over the course of the day can help keep glucose levels in check and energy levels up. For others, this can be a lot of effort for little return since their bodies do just fine with three meals a day. Regardless of which one is better for you, if you want to stay healthy and feel energized, make sure you eat enough to support your body's processes.
Limit Refined Carbs And Sugar

Do you ever feel exhausted after eating a high-carb meal? You are experiencing postprandial fatigue or a sugar crash. When you consume too many carbs or sugars, they break down quickly and cause your glucose to rise steeply. Your body responds by sending large amounts of insulin to normalize your glucose levels. Sometimes this can happen too soon, causing a rapid decline that can tax your body.
Sugary snacks may satisfy us in the short run, but the increased glucose swing can make us feel more tired. Rather than reaching for the sugar, go for carbs such as those found in vegetables, fruit, and honey, which can provide a good source of immediate energy.
Find the right Nutrisense programto turn insight into progress.
FAQs about feeling tired after eating and Nutrisense
Q1. Can a biosensor help me connect post-meal tiredness to what I ate?
A1. A Nutrisense glucose biosensor measures glucose in interstitial fluid around the clock. In the app, log meals, portions, and energy notes. Then review your curves one to three hours after eating to compare patterns with how you feel. Tag coffee, alcohol, and activity to add context. This can guide what to test next.
Source: Nutrisense App
Q2. Do I need a prescription to use Nutrisense for tracking post-meal fatigue?
A2. No. Nutrisense primarily uses over-the-counter Stelo sensors that do not require a prescription. Your membership includes sensors and access to the Nutrisense app for tracking and experiments around meals and energy. Choose a commitment length that fits your needs, and you can adjust your plan later if needed.
Source: CGM Plans
Q3. I feel sleepy after lunch. What simple one-week experiment can I run?
A3. Try a one-week lunch experiment. Days 1 to 3, keep your usual lunch and log portions, timing, and energy at 30, 60, and 120 minutes. Days 4 to 5, add a 10-minute walk right after eating and log again. Days 6 to 7, keep the walk and reduce the starchy side slightly. Compare your notes with the post-meal curves in the app.
Source: Nutrisense App
Q4. Can I work on post-meal tiredness if I already have a CGM?
A4. Yes. With Bring Your Own Sensor, you can connect a compatible CGM to the Nutrisense app and use analytics to explore post-meal fatigue. Pricing is $19.99 per month or $199 per year. You can also add nutritionist support options to plan experiments around meals, timing, and activity.
Source: Bring Your Own Sensor
Q5. How long does it take to spot meal-related patterns with Nutrisense?
A5. Many members start seeing useful post-meal patterns within one to two weeks of consistent logging. The biosensor records glucose in interstitial fluid every 15 minutes, giving you 24/7 trends to review after each meal. Tag meals, activity, and energy, then compare similar meals across different days to confirm patterns before making bigger changes.
Source: What is a CGM?
Go Beyond Glucose Data with Nutrisense
Your glucose can significantly impact how your body feels and functions. Thatâs why stable levels are an important factor in supporting overall wellbeing. But viewing glucose isn't enough. Nutrisense, youâll be able to learn how to use your body's data to make informed lifestyle choices that support healthy living.
One-to-one coaching
Sign up to access insurance-covered video calls to work with a glucose expert: a personal registered dietitian or certified nutritionist who will help tailor your lifestyle and diet to your goals.
Monitor and measure what matters
With the Nutrisense CGMÂ Program, you can monitor your glucose with health tech like glucose biosensors and continuous glucose monitor (CGM)s, and analyze the trends over time with the Nutrisense App. This will help you make the most informed choices about the foods you consume and their impact on your health.
Find your best fit
Ready to take the first step? Start with our quiz to find the right Nutrisense program to help you take control.
Go Beyond Glucose Data with Nutrisense
Your glucose can significantly impact how your body feels and functions. Thatâs why stable levels are an important factor in supporting overall wellbeing. But viewing glucose isn't enough. With Nutrisense, youâll be able to learn how to use your body's data to make informed lifestyle choices that support healthy living.
Coaching that Fits Your Day
Sign up to access insurance-covered video calls with a glucose expert: a personal registered dietitian or certified nutritionist who will help tailor your lifestyle and diet to your goals.
With the Nutrisense Program, you can monitor your glucose with health tech like glucose biosensors and continuous glucose monitors (CGMs), and analyze the trends over time with the Nutrisense App. This will help you make the most informed choices about the foods you consume and their impact on your health.
Find your Best Fit
Ready to take the first step? Start with our quiz to find the right Nutrisense program to help you take control.

Katie is a dietitian at Nutrisense. With over 11 years of experience as a dietitian in many areas of nutrition, Katie has worked as a clinical dietitian within a hospital, as well as in the fields of diabetes, sports and performance nutrition, recovery from addiction, and general wellness. Sheâs also an athlete and has run 8 marathons, including the Boston Marathon.


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