Weight Gain From Lack of Sleep

How could a lack of sleep cause weight gain? To understand the answer to that question we need to first understand the hormones our body naturally produces to make us hungry, and to let us know that our stomach is full.

We’ll start with the hormone Ghrelin. According to the US National Library of Medicine National Institute of Health:

Ghrelin is a multifaceted gut hormone which activates its receptor, growth hormone secretagogue receptor (GHS-R). Ghrelin’s hallmark functions are its stimulatory effects on food intake, fat deposition and growth hormone release. Ghrelin is famously known as the “hunger hormone”.

Hunger Hormones

To help explain what Ghrelin does, we can take a look at the first three letters of the hormone which stand for Growth Hormone Releasing. Simply put, Ghrelin makes you hungry and facilitates weight gain.

The other hormone that shares the distinction “hunger hormone” with Ghrelin is Leptin. While Ghrelin causes an increase in appetite, Leptin does the opposite and suppresses hunger.

Here’s the kicker: a lack of sleep causes an increase in Ghrelin, while simulatneously causing a decrease in Leptin. That’s a scary realization if you’re trying to lose weight while consistenly not getting enough sleep at night.

The way Ghrelin typically works is that your stomach releases the hormone to let your brain know it’s time to eat. When your body is sleep deprived it secretes a larger amount of Ghrelin, which increases your appetite. Normally when your stomach fills up your body will secrete Leptin to let you know that you’re full and can stop eating. However, sleep deprevation causes your body to secrete less Leptin than normal, meaning you may think you’re still hungry when you’ve already had more than enough food.

While this combination alone would be enough to show how a lack of sleep causes weight gain, the correlation between sleep deprivation and weight gain doesn’t stop there.

Emotional Eating

The emotional center of your brain, called the amygdala, shows increased activity when your body is sleep deprived. Meanwhile, the part of your brain that is responsible for rational thinking, your prefrontal lobe, becomes less active. This creates another dangerous cocktail for your brain that can lead to emotional eating.

To add it all up, by not getting enough sleep at night your body becomes more emotional, less rational, and makes you extra hungry without letting you know that you’re full.

The Bottom Line

Your body doesn’t enjoy a good night of sleep purely because you feel more refreshed in the morning, your body needs a full night of sleep in order to perform proper functions throughout the day. As an adult, you need at least seven hours of sleep per night for your body to function properly. The bottom line is that a good night of sleep is not optional if you want a healthy and happy body.

If you need help getting your full amount of sleep each night, head to our Sleep Tips page. If you feel like you may have a sleep disorder, or are curious if you may be at risk for one in the future, head over to our Sleep Quizes page to find out how you score.