Why Do You Get Tired After a Meal?

why do carbs make me tired

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You just ate a meal, and suddenly, you feel tired. You might even start to nod off in the middle of your favorite TV show. But how is this possible? After all, we’ve been told for years that we need to eat frequently to maintain our energy levels and weight.

What's going on in your body that makes you suddenly feel sleepy? And can anything be done to prevent this from happening? Read on to learn the answers to these questions and more. (try to stay awake)!

Reasons Why You Feel Tired After A Meal

Carbohydrates are the primary source of fuel for your muscles and your brain. When you eat a carbohydrate-heavy meal, carbs are broken down into simple sugars known as glucose. This glucose gets absorbed into the bloodstream. If we are performing exercise or our body needs to use this sugar then it is immediately put to use by our muscles. If we do not need the additional fuel, the glucose can be stored in our liver and muscles for later use.

While there is a limited amount of glucose that the body can store, it has an unlimited capacity for insulin. Insulin is a hormone that helps to pull glucose from circulation and into the cells to be used as fuel. Without insulin (or insulin that does not function properly), glucose continues to float around in our bloodstream and our blood sugar levels rise. 

If you eat a meal with carbohydrates, your body senses an increase in blood sugar. At this point your body wants to return to normal blood sugar levels so it deploys the hormone insulin to get our blood sugar back to homeostasis. The amount of insulin released is proportionate to the increase in blood sugar. So, the more our blood sugar spikes, the more insulin is needed to take glucose out of circulation and restore our bodies to normal. However, when we eat a big meal with lots of carbohydrates, the spike in blood sugar can be so great that insulin overreacts. When this happens, the insulin pulls more blood sugar form circulation that it should, causing your blood sugar levels to drop below average. This drop in blood sugar can make you feel tired and lethargic, resulting in a post-lunch slump.

How To Stop That Post-Meal Fatigue

If you want to deal with your post-meal slump, make sure you don't overeat, and stay active during and after eating. If you feel sleepy after every meal, talk with your doctor about alternative methods of staying energized without overeating or developing an unhealthy lifestyle.


When healthy individuals eat carbohydrates, the body releases insulin, which pulls glucose from circulation and puts it to use within the cells as energy. An overreaction by insulin can cause our blood sugar to dip too low and make us feel tired after eating a big meal. But it doesn't have to be this way.

carbs make me sleepy

Food Intolerance

Food intolerances are entirely different from food allergies. Food intolerance occurs when your body responds negatively to a specific type of food, but it doesn't usually involve the immune system.

There are many ways that your body can respond poorly to certain foods, making you feel tired after eating them. Overeating fat or sugar can affect you in this way because they're metabolized so quickly, meaning you aren't able to burn through all the energy they provide before your body needs more.

effects of caffeine

Caffeine Effects

Another potential reason you might feel tired after eating is if you're drinking too much caffeine. Caffeine is a stimulant that can help you feel more alert, but it also has a rebound effect.

This means that once the caffeine wears off, you might experience an energy crash that makes you feel tired and sluggish. Consuming caffeine with meals can amplify this effect, making you feel even more tired after eating.

Underlying Health Conditions

Several underlying health conditions can cause you to feel tired after eating. One such condition is diabetes, which affects the sugar levels in the blood and may make it difficult for your body to process food.

Additionally, if you suffer from hypoglycemia or low blood sugar, fasting between meals may not be an option for you.

How To Prevent Post-Meal Sleepiness

Carbs are one of the most important macronutrients for maintaining your energy levels. One of the main reasons you experience post-meal tiredness is that your body converts carbs into glucose to give you a burst of energy.

But after this initial boost, your glucose levels will start to drop again, causing that sudden onset of tiredness. Fortunately, there are some easy ways you can prevent this from happening.

Eat Smaller Meals

One of the simplest ways to stop getting tired after a meal is to eat smaller portions.  If you're eating too much at one sitting, it will take a while for the levels of dopamine in your brain to catch up with your body's need for food. As a result, you may start feeling tired and sleepy because your body needs time to digest the food that you just ate.

To avoid this sensation after eating, try eating smaller meals more frequently throughout the day. This allows your body time to adjust and keep its glucose levels steady so that you can maintain energy without feeling lethargic or losing weight.

how to exercise for more energy


If you're feeling tired after a meal, you may want to do some light exercises. The reason for this is that exercise is a healthy way to put glucose to use. When we perform physical activity our muscles can use glucose, which will pull blood sugar out of circulation and into the muscle. This is a great way to stabilize our blood sugar. As a bonus, exercise also helps to improve weight management, reduce the risk of cardiovascular disease, build muscle, and improve mental clarity.

Performing some light exercises before or after eating will help regulate blood sugar levels. But not all light exercises are created equal. For example, high-intensity exercises (sprinting, interval training, or stair running) requires more energy than low-intensity workouts (walking, an easy bike ride, yoga). So, the higher the intensity of the workout, the more blood sugar will be pulled from circulation as energy. 

alcohol and blood sugar

Limit Alcohol Intake

When you eat a meal, your body breaks down the carbohydrates and converts them into sugar. The sugar then stimulates your pancreas to produce insulin, which lowers blood sugar and tells your cells to use the sugar for energy. There are a couple of things you can do to help reduce the effects of low blood sugar.

Alcohol will bump up your blood sugar levels, but it will also make you tired and encourage a dip in energy. Alcohol also contains calories, so it's essential to be mindful of how much you're drinking when adding it to a carb-heavy meal.

Have A Protein-Based Snack

Have a protein-based meal or snack before or after a carbohydrate-laden meal. The protein will help stabilize your blood sugar levels and keep them from rising as fast.

 If you're feeling exhausted after eating carbs, consider reducing the size of your next meal, as this may be an indication that you're overdoing it on the carbs.


GOOD IDEA is a functional beverage designed specifically to reduce the post-meal spike in blood sugar. The drink is backed by 11 peer-reviewed research studied that demonstrate an average 25% reduction in blood sugar. By drinking 1/3 of a can before a meal and finishing the can with your food, we can work to reduce the spike, and subsequent drop, in blood sugar that can follow a carbohydrate-heavy meal.

dehydration impacts blood sugar

Stay Hydrated

The first thing many people do to stop the tiredness after a meal is drink some water. This is because the body needs water to metabolize carbohydrates. If you don’t stay hydrated, you will not process the carbs appropriately and could end up feeling fatigued.

Get Good Quality Sleep

If you're tired after a meal, it's possible that you're not getting enough quality sleep. That means a good night's sleep is the answer to your problem.

Try going to bed and waking up around the same time every day of the week, including weekends. This will help regulate your body's natural circadian rhythm, which is the 24-hour cycle of hormones affecting your mood and energy levels. You should also try to get at least 8 hours of sleep each night, even on days when you don't have to wake up early for work or school.

In addition to eating better, more frequent meals throughout the day can also help to stabilize sugar levels, which can aid in reducing fatigue. Stabilizing blood sugar can also reduce any cravings for sugars and sweets.

sleep and blood sugar

Bright Light Therapy

A morning walk is sure to wake you up and make you feel more energetic. But what if your body needs a little extra kick? It turns out light therapy might be the answer.

Light therapy involves exposing yourself to bright lights for 30 minutes or more each day. This can be done by using unique lamps that emit natural daylight or sitting near windows that receive lots of sun. Light therapy has been shown to help people with seasonal depression, depression, and even drug addiction.

The idea is that the light tricks your brain into thinking it's daytime, making less melatonin, which means you'll have more energy during the day.


Often, if you're tired after eating a meal, it can be due to large changes in blood sugar levels. Your body uses carbohydrates for energy, and when you eat too many carbs at once (like in a carb-heavy meal), your blood sugar levels begin to rise. After this rise, the body overcompensates with a phenomenon known as reactive hypoglycemia and blood sugar levels plummet. This can lead to you experiencing fatigue and other symptoms like dizziness and irritability.

I’m healthy individuals, blood sugar levels will eventually return to normal if they drop too low, and it's important to make sure your diet is balanced with the right amount of carbs, especially if they affect your energy levels or mood.  Once you understand how to manage and regulate your diet and blood sugar levels, you’ll be able to predict and control fatigue, irritability and energy. It’s an easy fix when you understand the triggers. Get some exercise. Drink up (water or a GOOD IDEA) and always aim for great sleep. Stay in tune with your blood sugar levels and you just may find yourself with an excess of energy vs a deficit after a meal. It’s a great feeling. Who knew? 

Edited & Updated (Jan 2023): Dr. Colleen Gulick