Why Do I Feel So Tired After Eating a Big Meal?

If you find yourself yawning profusely after a big meal, you're not alone. This feeling, known as postprandial somnolence or a "food coma," is often experienced after consuming a large volume of food, given the complex stages your body undergoes to break down everything you just ate.

Unlike an afternoon lull following your lunch, which can be attributed mainly to chemical processes and a mid-day drop in alertness, there is much more to the acceleration of fatigue brought on by overconsumption.

The bigger the meal, the more energy it takes to digest, and therefore the more your system has to work, which explains that onset of fatigue.

Do Certain Foods Cause Tiredness?

This particular type of exhaustion is more common in carb-heavy meals, the culprits commonly ranked as foods high on the glycemic index that flood the bloodstream with glucose.

Foods high in white starchy carbohydrates, such as bread, pasta, and cakes, tend to have this effect. This is due to a spike in blood glucose levels that initially gives you a boost before it plummets and causes a drop in energy.

Also, many protein food sources are high in tryptophan, the precursor for serotonin—both of which are known to increase our rate of sleepiness.

Alongside specific carbs and protein sources: "processed, packaged or heavy, dense foods ask our body to work harder to break them down and digest them," says holistic nutritionist and the founder of Doing Well, Daphne Javitch.

"As eating requires internal energy, our body has to break down food matter (digest, assimilate, eliminate) meaning overeating can overwork our system and cause exhaustion."

In addition, gulping alcohol alongside a large meal can spark drowsiness. This is because alcohol has sedative effects, and also slows down the rate of digestion, as our system is not built to absorb high volumes of alcohol.

Other Reasons for Feeling Tired After a Large Meal

The Quality of Your Food

What we put into our bodies can heavily impact how we feel and function. It's true that every individual handles and processes food uniquely, but we know that certain foods are prone to making us feel more or less energized.

Diets incorporating a variety of foods to balance the quality between dietary fiber, fats, carbs, and protein have also been found as optimal to fuel our body more efficiently.

Pace of Eating

It takes our brain time to send a signal to our stomachs that we are full, and so pace plays a role in determining our satiety.

One study found that those who ate their meal at a slower pace reduced their appetite and eating later on. This slow rate group also consumed 25% fewer snacks in the same day.

This is partly due to ghrelin, the "hunger hormone," which plays a role in appetite regulation. It can take a while for this hormone to decrease and for our satiety hormone to kick in, so you can finish a large meal before you actually feel overly full. And so often, we consume large quantities without hunger as the driver.

Mindfulness has been proven as a successful intervention to reduce bouts of emotional and binge eating, but can be applied to any situation, including a setting when a large meal is on the menu.

Bringing awareness to what you put in your mouth can better control how fast you eat and reduce the intake of unnecessary calories.

Medical Conditions

There are a number of conditions that can affect your post-meal energy levels, including:

Diabetes

A translational metabolic syndrome research study found that individuals with diabetes are more inclined to experience fatigue in general, and this is especially acerbated with diet.

If someone with Type 1 or Type 2 diabetes feels tired after eating, it could be a symptom of hyperglycemia (high blood sugar). This only worsens if there’s insufficient insulin to transport sugars, leaving your cells without enough energy, which explains why insufficient insulin can leave you feeling tired. If you have diabetes, you may want to discuss your fatigue levels with a health care practitioner to ensure you're receiving the correct treatment.

Food Intolerance or Food Allergy

Food intolerances (such as gluten intolerance), allergies, and reactions to additives can impact digestion or other bodily functions. When you eat something your body perceives as foreign, your immune system works hard to fight it off. This can result in feelings of fatigue.

Underactive Thyroid

Fatigue is a common symptom of thyroid disease, and although thyroid issues arise from the immune system attacking the thyroid gland, diet can play a role in managing the symptoms.

Specific foods, such as soy, raw cruciferous vegetables, and dried fruits may interfere with thyroid medication or function, leaving you feeling depleted of energy. Therefore, consuming a large meal with less than desirable foods can negatively affect your thyroid function and leave you feeling wiped out.

How To Avoid Feeling Tired

Eat Smaller Meals More Frequently

Aim for smaller, spaced-out meals throughout the day to balance your caloric intake. This way, instead of overpowering our digestive systems with an abundance food, we are able to process what we eat in smaller chunks to stabilize our blood glucose and keep us feeling satisfied between meals.

Eat More Macro-Focused Meals and Whole Foods

Loading up on junk food can exhaust our bodies, forcing them to work in overdrive to eliminate what we don't need. When possible, stick to unprocessed, whole foods that are balanced in protein, fat, and carbohydrates to keep your energy leveled throughout the day.

Get Quality Sleep

Sleep serves multiple purposes for our health and wellbeing, and ignoring this basic need can be detrimental to our health. Studies have confirmed a link between sleep deprivation and a desire for unhealthy foods, with sleep loss, not hunger, increasing junk food cravings.

In balancing a solid night's sleep with healthy food choices and sensible quantities, you can help ward off post-meal fatigue.

A Word From Verywell

While it is common to feel tired after a meal that is larger than usual, if you frequently feel tired after eating, you may want to speak with a health care professional. Eating a well-balanced diet and getting adequate physical activity throughout the day can help to keep you feeling energized on a regular basis. Embracing more mindful eating practices, such as Intuitive Eating, may help to improve your post-meal satiety levels and help you to avoid excessive fatigue.