Why Do We Feel Sleepy After Eating?

Table of Contents (click to expand)

The main reason we feel sleepy after eating is because of the release of insulin. Insulin helps to regulate blood sugar levels, but when we eat a lot of starchy or sugary foods, it can cause our blood sugar levels to spike. This then causes our body to release more insulin, which can make us feel sleepy. Other factors that can contribute to feeling sleepy after eating include the release of serotonin and melatonin, as well as the presence of potassium and magnesium in some foods.

We’ve all been there. As soon as you’re done eating a hearty meal, a huge wave of drowsiness kicks in and you can barely keep your eyes open. You’ll be sitting there with that empty plate of yours, wondering what it is about the food that you just ate that’s shutting down your brain.

Was it the rice? There is a common assumption that rice makes us feel sleepy.

It’s time to take a look at the various factors that could be contributing to our post-meal nap needs.

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Insulin Resistance

In our quest of getting to the bottom of why food makes us sleepy, let’s first consider the biggest part of our diet: Starch-filled and sweet foods like rice, bread, potatoes, sweet drinks, etc.

Starch Staples
Credits:Robyn Mackenzie/Shutterstock

In our bodies, starchy and sweet foods increase the glucose content of our blood. In response to this increase in blood glucose levels, insulin is secreted. Insulin basically enables glucose uptake by the cells of our body. Since glucose is required by our cells to produce energy, insulin is vital to our daily activities and energy levels.

The problem arises when we eat too much of these types of foods. When we load up on a starchy meal, our blood glucose levels spike and an excess of insulin is secreted into the bloodstream to manage this insane amount of glucose. Due to constant action by insulin on the body cells to lower chronically high blood glucose levels, our cells develop a resistance to the action of insulin. This insulin resistance is really bad news for your body; from that point on, it becomes very difficult to manage blood glucose levels, and your energy levels will start decreasing, since insulin can no longer stimulate glucose to go into the cells.


Finally, we reach the part where sleepiness starts kicking in. Due to our high blood sugar level after eating a starchy meal (and insulin’s inability to get it into our cells due to insulin resistance), the body starts converting the glucose into fat for storage. This conversion process is highly taxing on the body’s energy reserves and results in that well-known state of post-meal sleepiness.

Also Read: Why Do We Wake Up Hungry After Overeating?

Brain Activity

A variety of foods also cause changes in brain activity by influencing one or more chemicals in the brain. Carbohydrates, for example, provide our bodies with the precursors required for the synthesis of the neurotransmitter serotonin, which calms us down. It therefore makes sense that eating a carb-rich meal will produce an excess of serotonin, leading to us being a bit too calm and relaxed, also known as “asleep”.

man sleeping calm meme

Moving on to high-protein foods, like meat, fish, cheese, eggs etc.; they contain the amino acid tryptophan, which is used by our bodies as another precursor for serotonin. Once again, the calming effect produced may be too much for us to handle, and we’ll be dozing off before dessert.

tryptophan meme
Credits:Valentyn Volkov/Shutterstock

Another chemical involved in the onset of sleep is the hormone melatonin. The main role of this hormone in our bodies is to directly bring about sleep. Therefore, eating foods like cherries, which contain a small amount of melatonin, may send a signal to our bodies telling us that it’s time for a nap.

Cherries Meme
Credits:Shulevskyy Volodymyr/Shutterstock

Also Read: How Does Sugar Affect Our Brain?

Just Relax

Once your banana has ripened, all you have to do is peel back its skin and enjoy. What may surprise you, however, is that bananas contain potassium and magnesium, both of which play a role in relaxing your muscles. This feeling of relaxation after eating a delicious banana may also contribute to your sleepiness. Good luck staying awake after eating all of these delicious types of food, but remember… you’re not the only one dealing with after-dinner drowsiness!

Yellow Banana Meme

References (click to expand)
  1. Why do we feel sleepy after eating? - How It Works. howitworksdaily.com
  2. The Science Of The Siesta - Indiana Public Media. WFIU
  3. Food coma - Go Ask Alice!. Columbia University
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About the Author

Brendan has a Bachelors of Science degree in Biotechnology from Mumbai University (India). He likes superheroes, and swears loyalty to members of the Justice League. He likes to take part in discussions regarding the human body, and when he is not doing that, he is generally reading superhero trivia.