5 Negative Effects Staying Up Late Has On Your Body

5 Negative Effects Staying Up Late Has On Your Body



“We’ve known for years now that people who engage in shift work, at night, are at much greater risk of cardiovascular disease, diabetes, and a host of other problems.” – Dr. Courtney Peterson, Physician at Pennington Biomedical Research Center

You are likely one of two kinds of people: a “morning lark” or a “night owl.” Like the pull of the North and South poles, people gravitate to one or the other on the “morning/night tolerance scale.”

As this writer leans heavily to the “owl” side of the scale, it brings me no joy to bring disheartening news to my fellow night owls. Before giving credit where it’s due: to science, research, and…(ugh) “morning people”…a short tirade.

I despise mornings. The alarm clock buzzes and I wish I could haul it from my 4th story apartment window. 7 am? Really? Did I ACTUALLY get 8 hours of sleep, because it feels like I just FELL asleep! Coffee…coffee…could someone bring me some dang coffee so I could function? Oh. I live alone. I hate my life. Nobody talk to me.

Yes, this writer is a night owl. Always has been, and probably always will be.


But I’m also a big proponent of the scientific method; observation, proof, evidence, all that. Therefore, objectivity is required, and therefore we’ll (albeit, grudgingly) oblige.

Here’s the uncomfortable truth, my fellow warriors of the night: it’s bad for your health. Here’s a second uncomfortable truth: science has largely nullified any counterargument to the contrary.  

Here are 5 negative effects that *sniff, sniff, tear* staying up late has on your body:

1. It weakens the immune system

Our immune systems are inextricably linked to a predisposed sleep and wake cycle – the circadian rhythm. In its “natural” state, our circadian rhythm is programmed for 12 hours of light and 12 hours of dark; when this internal body clock is toyed with, our immune system suffers.

In a study published in the journal Science, researchers observed the negative effects of tinkering with the circadian rhythm. Light-cycle disruptions were shown to increase “proinflammatory immune cells that protect against bacterial and fungal infections.”

2. It’s bad for brain health

Scientists at Aachen University in Germany administered brain scans of 59 people categorized into three groups: 16 early risers, 23 night owls, 20 and “intermediates.” Analyzing the scan results, scientists concluded that night owls possessed less “white matter integrity” in various areas of the brain.


“White matter” in the brain is a fatty tissue that facilitates communication between neurons; how the brain sends signals various areas of the body to turn “on” or “off.”

Disproportionate levels of white matter suppress the brain’s ability to transmit signals these across the brain and body. To date, abnormal white matter levels have been linked to depression and impaired cognitive function.

3. Our eating habits tend to suck

Oh, and besides having a weakened immune system and potentially unhealthy brain, us night owls stuff our faces more too.

In a 52-person study undertaken at Northwestern University, and published in the journal Obesity, researchers found a link between sleeping patterns and poor eating habits.

Dr. Phylliss Zee, senior author of the study, states: “When sleep and eating are not aligned with the body’s internal clock, it can lead to changes in appetite and metabolism, which could lead to weight gain.”

Here are some specific findings of the study; night owls:

– Ate 248 more calories throughout the day.


Consumed twice as much fast food.

– Ate half as much fruits and vegetables.

Drank more full-calorie soda.

– Had a higher body mass index (BMI), a measure of body weight. 

4. It negatively alters melatonin production

Melatonin is a hormone produced in the pineal gland that regulates sleep and wakefulness. Exposure to light stimulates a pathway from the retina of the eye to the brain’s hypothalamus, where the suprachiasmatic nucleus (SCN) is located.

The SCN, in addition to producing melatonin, fires signals to parts of the brain that control body temperature and hormone levels.

Typically, the aforementioned physiological response occurs at approximately 9 PM – a time when night owls, although not completely alert, are far from nodding off.

Inspiration to your Inbox


The brain and body are finely tuned to adapt to changes in the environment, including self-inflicted ones (i.e., habits.) What this means for night owls is underproduction of melatonin and – as less melatonin is available – disruptions to the hormone’s various functions.

5. It increases the risk of diabetes and metabolic syndrome

According to a research study published in the Journal of Clinical Endocrinology & Metabolism, “Men who are night owls are more likely to have diabetes and female night owls as twice as likely to have metabolic syndrome as their early rising equivalents.”

Related article: 5 Diseases That Can Grow In Your Body When You Don’t Sleep Enough

While the reasons for these effects are hazy, researchers suggest that diet (eating calories after 8 pm) and overexposure to artificial light – two common behaviors of night owls – can both influence metabolic functions.

A couple of other things…


Here is some interesting research-based info about sleep/wake cycles:

– There is no observed correlation with intelligence, success, and one’s sleep/wake cycle. (Sorry, Ben Franklin)

– Whether you’re a morning person or night owl is thought to be genetically determined. Called the period-3 gene, the “long version” of period-3 are morning larks, while those with the “short version” are owls.


– It is possible, though difficult, to change from an owl to a lark. To do so requires discipline, patience, and time-management. Theoretically, by waking up 20 minutes earlier each day (at the latest, 6 am) and hitting the lights, the brain can slowly recalibrate. Here’s the kicker: weekends are no exception.

Or, you can just love being a lark or an owl, roll the dice and enjoy life…yeah, that sounds good.

Bremer, S. (2015, April 17). Health issues for those who stay up late. Retrieved March 30, 2017, from http://www.pharmaceutical-journal.com/opinion/blogs/health-issues-for-those-who-stay-up-late/20068371.blog

Breus, M.J, Dr. (2013, December 1). Night Owls and Early Risers Have Different Brain Structures. Retrieved March 30, 2017, from http://www.huffingtonpost.com/dr-michael-j-breus/night-owl-sleep_b_4276411.html
Brodwin, E. (2015, April 9). Staying up late might be bad for your health – but not because you’re getting less sleep. Retrieved March 30, 2017, from http://www.businessinsider.com/is-staying-up-late-bad-for-you-2015-4
Gallardo, M. (2011, May 4). Study: Staying up late tied to poor eating habits, weight gain. Retrieved March 30, 2017, from http://scopeblog.stanford.edu/2011/05/04/staying_up_late/
Norton, E. (2013, November 7). Why Late Nights Are Bad for Your Immune System. Retrieved March 30, 2017, from http://www.sciencemag.org/news/2013/11/why-late-nights-are-bad-your-immune-system
Parker-Pope, T. (2011, November 18). So You Think You Can Be a Morning Person? Retrieved March 30, 2017, from https://well.blogs.nytimes.com/2011/11/18/so-you-think-you-can-be-a-morning-person/?_r=0
The National Sleep Foundation. (2017). Melatonin and Sleep. Retrieved March 30, 2017, from https://sleepfoundation.org/sleep-topics/melatonin-and-sleep
Wikipedia. (2017). Suprachiasmatic nucleus. Retrieved March 30, 2017, from https://en.wikipedia.org/wiki/Suprachiasmatic_nucleus
Yu, X., Rollins, D., Ruhn, K. A., Stubblefield, J. J., Green, C. B., Kashiwada, M., . . . Hooper, L. V. (2013). TH17 Cell Differentiation Is Regulated by the Circadian Clock. Science, 342(6159), 727-730. doi:10.1126/science.1243884
(C)Power of Positivity, LLC. All rights reserved


Leave a Reply

Our passion is to serve and bring the best possible positive information, news, expertise and opinions to this page. We want to help our community find and shine their inner light - the truth of love, light, and positivity that is within us all! Read more about Power of Positivity...

Follow Me: