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Food Coma: Is It Real and How to Cope with a Food Coma

We’ve all experienced it: the post-Thanksgiving dinner urge to nap, having a “food baby” and wanting to lie down, or simply feeling drowsy after a big meal. Is the post-lunch slump a real thing? Keep reading to discover the myths — and truths — about a food coma.

What is a food coma?

Post-meal grogginess, or a food coma, is a feeling of drowsiness and low energy after a large meal, and it actually has a scientific name: postprandial somnolence. This drowsiness isn’t the kind of sleepiness you experience when it’s time for bed. Instead, it’s a particular state of contentment, maybe a little overfullness, and feeling less alert. Some people may also feel light-headed and unmotivated, which may explain why many workers experience a post-lunch slump in productivity.

What causes a food coma?

What is a food coma? There are both misconceptions and scientific truth behind the phenomenon.

The myths

It’s commonly thought that certain enzymes, most notably tryptophan, cause food coma symptoms. The sleepiness people often experience post-Thanksgiving dinner is often attributed to a high concentration of tryptophan found in turkey. However, the amount of tryptophan in turkey is about the same as what’s found in other meat, especially different kinds of poultry. It’s more probable that the drowsiness experienced after a Thanksgiving meal is linked to the simple-carb dishes that typically accompany the meal, like mashed potatoes, stuffing, corn, and desserts.

It is true that tryptophan can produce effects of drowsiness and sleepiness, especially in children, but the effects from a couple of servings of turkey are the same as from an equivalent amount of chicken. It’s the insulin surge from all the carbs that are consumed alongside the turkey that allows the tryptophan to enter the brain. So eating a plate of turkey may not make you sleepy, but eating turkey with potatoes and other carbs might make you feel like you need a nap.

Another myth is that a large meal requires extra blood flow to the digestive system and reduces the blood flow to the brain. This myth may explain why you feel a little “brain dead” after a buffet, but it simply isn’t true. The extra blood needed by the digestive system is actually routed from the skeletal-muscular system. In addition, the amount of blood pumped per minute by your heart increases, aiding digestion and carrying the increased amounts of glucose and nutrients to your cells. 

How digestion works

Chewing and swallowing is only the first step in digesting food. Next it goes to the stomach, where it is broken down. Then it passes into the small intestine, which extracts the nutrients from the resultant slurry. It’s here that a lot of chemical reactions begin to occur, which can trigger the onset of postprandial somnolence.

Blood and energy are diverted from nonessential functions of the body to process the food, and the larger a meal is, the more energy and blood it requires. For example, a Thanksgiving feast probably results in an “all hands on deck” signal from your gut. Certain digestive hormones probably signal your brain to rest in order to process the meal.

The scientific truth

After a big meal, your brain switches from the sympathetic nervous system to the parasympathetic nervous system. Simply put, when you’ve eaten a big meal, your brain moves from a general state of readiness for fight or flight to a more autonomic state of wanting to be at rest and less alert. Digestive hormones tell your brain to switch from one operating system to the other. 

How to cope with a food coma

The easiest food coma cure is to avoid it altogether. However, if you’re reading this article, you’re probably familiar with the condition. After a large meal, instead of moving from the table to the couch, try taking a walk around the block. A 20-minute brisk walk can help shake off some of the fogginess from overeating. When you’re walking at a brisk pace, your body will demand more glucose, and the exercise will help reduce the amount of glucose and insulin in your bloodstream.

Ways to prevent a food coma

What you eat, in addition to how much you eat, can determine whether you experience “dinnertime dip” feelings. Excessive amounts of carbohydrates and sugar increase the amount of glucose in the bloodstream, which, in turn, signals the body to produce more insulin. Insulin is a hormone that “opens the door” to cells in your body, allowing some nutrients and chemicals in — most notably, tryptophan.

Balanced meals, especially those rich in protein and foods with a low glycemic index (foods that produce less glucose) don’t have the postprandial somnolence effect that high glycemic index foods do. Eating plenty of vegetables can help regulate your digestive system, as well. A high volume of veggies can produce a full feeling without overloading the body with glucose. Make sure that you’re drinking enough water, too. Dehydration can produce groggy feelings and make you tired and less alert. 

Even if you eat meals high in protein, eating too much can still make you feel groggy or overfull and unmotivated. A general rule of thumb is that a proper portion of food is about the size of your closed fist. Eat slowly, allowing the hormone leptin to signal your brain that your stomach is full.

Possible side effects of a food coma

Generally, the side effects of a food coma may include things like falling asleep at your desk after lunch or snoring on the couch post-Thanksgiving dinner. However, if you consistently have postprandial somnolence, it may indicate that you’re eating too many carbs and not enough lean meats and veggies.

In the presence of other factors, excess glucose in your bloodstream after each meal and the resultant insulin spikes can lead to a condition called insulin resistance, which is a precursor to type 2 diabetes. If your body is consistently producing a high amount of insulin, the cells in your body may become insulin resistant, which means that instead of insulin opening the door for nutrients and glucose, the cells are keeping their doors firmly closed.

This, in turn, leads to high volumes of glucose in the bloodstream, making the blood thicker and damaging your arteries and veins. High blood glucose levels can lead to type 2 diabetes, a disease that damages many systems in the body and can lead to blindness and gangrene in the extremities.

A final note on food coma

You don’t have to stop eating your favorite foods to avoid post-meal drowsiness. In fact, you can still eat what you’d like, just in moderation. Making sure your meals are balanced and following good portion control guidelines can help you avoid a slumpy, groggy feeling after dining.



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