What Happens To Your Body When You Can’t Sleep


There are nights when most of us can’t sleep right away. Moreover, we toss and turn and may be ultimately we fall asleep. And, we get up in the morning not getting as much sleep as we normally do.

Or some of us may have jobs working the night shift. And those working the night shift get their abbreviated sleep during the “day”.
can't sleep

Sleeping Guidelines

Most noteworthy, the National Sleep Foundation’s latest recommendations on the amount of sleep we really need are as follows:

  • First of all, young adults aged 18 to 25 should sleep between 7 to 9 hours
  • Also, adults aged 26 to 64 should sleep between 7 to 9 hours
  • Finally, older adults age 65 and up should sleep between 7 to 8 hours

Furthermore, sleep times for those under 18 years of age are available from the National Sleep Foundation.

Effects on the Body When You Can’t Sleep

But what happens if you can’t sleep according to these recommendations? Most of all, not getting sufficient sleep effects your body in different ways, including:

  • Hormonal change
  • Circle
    Being stressed
  • Circle
    Reaction of the brain’s frontal lobe and primal structures
  • Circle
    Reaction of the Endocannabinoid System
  • Circle
    Molecular Level Changes

Hormonal Changes

The December 2004 edition of Scientific American reported on hormonal changes in anyone who can’t sleep more than 5 hours. Above all, compared with those who slept 8 hours, the sleep deprived, had significant differences in the hormones leptin and ghrelin.

First of all, the adipocytes of white adipose tissue (also known as fat) produce the hormone leptin. And, leptin's primary target is the brain's hypothalamus. Most noteworthy, low levels of leptin signals starvation. As a result, the body’s appetite increases.

In addition, the hormone Ghrelin, produced by the stomach, is an appetite stimulant. And, the more ghrelin you have the more you want to eat.

In fact, those who can’t sleep more than 5 hours had 16% less leptin than those sleeping 8 hours. In addition, they had 15% more ghrelin than those sleeping 8 hours. Consequently, because of the low levels of leptin, the sleep deprived were starving. While the increased levels of ghrelin made the sleep deprived want to eat more than necessary.

As a result, frequent episodes of inadequate sleep results in the sleep deprived accumulate more fat and gain weight.

Being Stressed

If you can’t sleep you are sleep deprived. And, the greater you are sleep deprived, the higher your levels of the stress hormone cortisol. Moreover, the higher the cortisol levels the greater your appetite. In addition, when you are stressed, the body produces serotonin to calm you down. And, the easiest way to produce serotonin is to eat high-fat, high-carb foods.

Also, when you are sleep deprived, the mitochondria in the cells that digest fuel (i.e. sugar) start to shut down. As a result, sugar remains in your blood causing you to have high blood sugar. Furthermore, insufficient sleep makes your fat cells 30% less able to deal with insulin.

Most of all, when you can’t sleep and are sleep deprived your body goes into survival mode. Sleeplessness makes your body think you are in danger. As a result, your metabolism slows down. Consequently, the body tries to save its resources and the body also wants to ingest more fuel. As a result, you gain weight.

Reaction of the Brain’s Frontal Lobe and Primal Structures

An August 2013 study from US Berkeley, used functional Magnetic Resonance Imaging (fMRI) to observe effects of insufficient sleep.

Firstly, of those who can’t sleep sufficiently or had a sleepless night, the brain’s frontal lobe showed impaired activity. Above all, the brain’s frontal lobe governs complex decision-making.

In addition, the study found increased activity in deeper brain centers that respond to rewards. Moreover, the sleep deprived participants favored high-calorie unhealthy snacks and junk foods.

Especially relevant, lack of sleep blunts complex judgments and decision making. Also, lack of sleep causes primal brain structures that control motivation and desire to get amplified. As a result, people, who can’t sleep according to guidelines, tend to be overweight or obese. On the other hand, getting enough sleep promotes healthy weight.

Reaction of the Endocannabinoid System

A study by the National Institutes of Health looked at a different link between those who can’t sleep per the guidelines and weight.  Most noteworthy, sleep deprivation effects the body similar to activation of the endocannabinoid (eCB) system by chemicals in marijuana. The eCB has a significant role in the brain’s regulation of appetite and energy levels. In fact, the eCB affects the brains’ motivation and reward circuits and can cause a desire for tasty foods.

Furthermore, when compared with someone sleeping 8.5 hours, those who can’t sleep that long had high eCB levels. And those levels lasted a long time.  Moreover, the high eCB levels caused increase in hunger and appetite. Because their eCB levels were the highest, the sleep deprived consumed more unhealthy snacks in between meals.

This suggest that high eCB levels drive hedonic, or pleasurable eating. Most noteworthy, when you see junk food after sleeping per guidelines, you control your natural response and not eat it. But when you are sleep deprived because you can’t sleep, your hedonic drive for certain foods gets strong. Also your ability to resist junk food becomes weaker. As a result, you are more likely to eat junk food and put on weight. Furthermore, the more days that you are sleep deprived the more weight you will put on.

Molecular Level Changes

Metabolic Functions

Other studies have shown that if you can’t sleep the recommended length, inflammation of tissues occurs. Specifically the adipose tissues and skeletal muscle tissues exhibited disrupted metabolism in anyone who is obese. Most of all, disrupted sleep and circadian rhythms adversely affect metabolic functions regulated by adipose tissue and skeletal muscles.

Adipose Tissue

Most noteworthy, adipose tissue or fat is a loose connective tissue composed of adipocytes. And, the adipose tissue is located beneath the skin (subcutaneous fat), around internal organs (visceral fat), in bone marrow (yellow bone marrow), intermuscular, and in the breast tissue. Also, the adipose tissue’s main role is to store energy in the form of fat.

Most of all, because you can’t sleep the recommended length, molecular changes occur at the tissue level. Specifically, the adipose tissue attempts to increase its capacity to store fat - resulting in weight gain.

Skeletal Muscle Tissue

Skeletal muscle tissues exhibit disrupted metabolism in anyone who is obese.

  • First of all,  skeletal muscles breakdown skeletal muscle proteins
  • Circle
    And,changes in skeletal muscle levels of proteins involved in handling blood glucose impairs glucose sensitivity

DNA Methylation

Next, the same studies reported changes in DNA methylation.

First of all, tests show that those who can’t sleep the recommended length have tissue specific changes due to DNA methylation. Specifically, these changes regulate the turning on or off of genes in each cell.

Most of all, DNA methylation is a process by which methyl groups are added to the DNA molecule. And, this addition modifies the function of the DNA segment. Most noteworthy, hereditary and environmental factors like exercise, famine, etc.  affects DNA methylation.

Furthermore, sleep loss changes the degree of DNA methylation in genes spread throughout the human genome.

Most of all, sleep loss causes changes in DNA methylation only in the adipose tissue. And most noteworthy, it only effects genes altered by DNA methylation due to obesity.

Circadian Rhythm

Furthermore, the same studies reported the following.

First of all, acute sleep loss results in changes to clock genes that, within each tissue, regulate the tissue’s circadian rhythm. Most of all, the circadian rhythm is a 24-hour internal clock that cycles between sleepiness and alertness at regular intervals. Also, the biggest dip in energy happens between 2AM to 4AM, and between 1PM to 3PM. Moreover, you won’t feel the dips and rises if you had enough sleep.

Furthermore, parts of the hypothalamus controls circadian rhythms. However, light and darkness impact it too. Most noteworthy, those who can’t sleep the recommended length, negatively impact their tissue’s circadian rhythm.


The same studies have shown that

  • First of all, those who suffer from chronic sleep loss or those who work the night shifts have increased risk of obesity
  • Circle
    Next, chronic sleep disruption and circadian rhythms increase the risk of developing obesity
  • Circle
    Also, disrupted sleep results in weight gain  in which fat is increased at the same time as muscle mass is reduced
  • Circle
    Furthermore, diet and exercise can alter DNA methylation and possibly counteract the adverse metabolic effects arising because you can’t sleep the recommended length
  • Circle
    Finally, one or more nights of recovery sleep can normalize metabolic changes at the tissue level that resulted because you can’t sleep the recommended length.

Partial Sleep Deprivation

A November 2016 European Journal of Clinical Nutrition study reported results for those who can’t sleep the recommended duration. Most of all, the partial sleep deprivation resulted in eating significantly high fat, low protein foods which increased ingestion of calories. And since there was no change in calorie expenditure or the resting metabolic rate, partial sleep deprivation contributed to weight gain.

Effect of Losing 30 Minutes of Sleep a Day

Even if you can’t sleep for 30 minutes a day it can have significant effects on obesity.  Moreover, according to a study, sleep loss is additive with metabolic consequences. And, the study found those who don’t get a complete night’s rest were 72% more likely to be obese. Furthermore, during the study they found that after 12 months, for every 30 minutes of weekday sleep loss, the risk of obesity increases by 17%.

Effect of Sleep Loss on Weight

Women, who can’t sleep for more than 5 hours a night, had the greatest weight gain followed by those reporting sleeping 6 and 9 hours a night. Women who reported sleeping 7 or 8 hours a night had the lowest weight gain.