Science Explains: Why Eating Makes Us Feel Sleepy & Tired & How to Prevent This

If you’ve been a “victim” of a food coma, you may be wondering what’s really going on, right? 

This experience is frequent after large meals, like those we have during Christmas or Thanksgiving. 

Also known as food coma or postprandial somnolence, this is a feeling of sleepiness and tiredness after consuming food. 

Despite the limited science on how or why this food coma happens, there are theories. 

Food Coma Explained

A food coma or postprandial somnolence is tiredness after a meal. It’s also known as a post-lunch dip which is often experienced after consuming lunch in the afternoon. 

Other accompanying symptoms are lethargy, sleepiness, physical tiredness, low levels of energy, and poor focus. Despite containing the word ‘coma’, one doesn’t actually lose consciousness. 

A food coma isn’t to be confused with a serious medical condition known as a coma. A food coma, although it’s reported frequently, it’s not studied enough. 

Below, check out some of the proposed reasons why we’re subject to food coma.

The Possible Triggers of a Food Coma

  1. Blood circulation changes

Food coma was thought to be caused by an elevated blood flow to the gut, resulting in a reduced blood flow to the brain. 

But, our body can maintain blood flow to the brain in plenty of stressful situations, like when we exercise and the muscles need more blood, so it’s not a theory that can’t be challenged. 

So, it’s unlikely that the flow diverts sufficient blood flow resulting in sleepiness. 

  1. A big meal

According to studies done with fruit flies, bigger meals, especially those abundant in salt and protein, caused longer, after-meal sleep. 

In a study done with men consuming pizza, the ones who overate reported less energy and more sleepiness and lethargy in four hours after the meal. 

Those who ate comfortably until full didn’t experience any of these symptoms.

  1. Meals rich in protein,  carbs, and fat

These macronutrients encourage sleepiness by influencing each other. 

For example, a meal rich in carbs may increase the levels of tryptophan, an amino acid that elevates the serotonin amount, a hormone linked with sleep in the brain. 

Moreover, a meal rich in protein may cause sleepiness if it contains a lot of tryptophan. For example, eggs, cheese, chicken, milk, tofu, etc.

  1. Brain sleep centers are activated by eating

Eating releases hormones and neurotransmitters which activate parts of our nervous system that are responsible for digestion. 

And, certain pathways in the brain participating in digestion overlap with ones involved in tiredness and sleep. 

So, when they’re triggered for digestion, one may become sleepy. Some hormones released around mealtime may influence sleep. 

  1. The natural sleep rhythm

Plenty of people have a post-lunch dip in the early afternoon. 

Our body has a 24-hour sleep-wake cycle or the circadian rhythm. 

According to research, in addition to the expected sleep at night, a small sleep phase happens in the early afternoon, or the 12-hour harmonic. 

This period has been observed through drops in work performance and an increase in vehicle accidents, between 2 and 4 pm. 

As a result of this natural dip in the circadian rhythm, many countries have afternoon naps as part of their culture. For example, siesta time in Spain.