Sleep is more important that you probably think.
The past two weeks have been BRUTAL. Waking up every day at 5:10 a.m. so that I could be out the door and running with the girls by 5:45 was catching up to me because I wasn’t getting to bed until midnight or later each night.
The result?
My runs felt sluggish, I felt fatigued all day, and I almost always wound up taking an involuntary nap for 1-2 hours in the middle of the day (good thing I was working from home!).

Sleep and Weight Loss Studies
There have been numerous studies done on the effects of sleep deprivation and weight gain/loss. And not getting enough sleep can cause hormone imbalances, which can wreak havoc on both your appetite and your metabolism.
According to Dr. Michael Breus, Clinical Psychologist and Board Certified Sleep Specialist, sleeping less causes you to consume more calories. Some of the reasons he lists are outlined below.
How Sleep Loss Negatively Impacts Your Weight
- Changes to your glucose metabolism – causes your body to store the calories you consume, storing them as fat vs. burning them for energy
- Increased production of cortisol – a stress-hormone that stimulates your appetite, prompting you to eat more
- More time for food – because if you’re not sleeping, you have more time to eat [source]
According to Breus, there are two key hormones that factor into the sleep loss vs. weight gain equation: grehlin and leptin.
Grehlin is the hormone responsible for letting us know when to eat, while leptin is the hormone responsible for telling us when to stop eating. When we are sleep deprived, we have more grehlin and less leptin. Breus continues:
It’s not so much that if you sleep, you will lose weight, but if you are sleep-deprived, meaning that you are not getting enough minutes of sleep or good quality sleep, your metabolism will not function properly. [source]
Nurses’ Health Study
One of the longest sleep/weight studies ever conducted was the Nurses’ Health Study, which followed 68,000 middle-age American women for 16 years. According to the results of the study, women who slept five hours or less were 15 percent more likely to become obese.
A later version of the study, which looked at a cohort of younger women who worked rotating night shifts at work, found that the risk for developing diseases such as diabetes and obesity were significantly greater due to irregular circadian rhythms, caused by the nature of their jobs. [source]
University of Colorado Study
In a study conducted at the University of Colorado, sleep researchers tracked the sleep, metabolism and eating habits of 16 healthy men and women for two weeks. The subjects stayed in a monitored room that allowed researchers to record specific information – from the amount of oxygen they used to every single bite of food that was eaten. Strict sleep schedules were imposed, and the goal was to determine how one week of inadequate sleep would affect a person’s behavior, weight and physiology.
During the first week of the study, half of the subjects were allowed to sleep nine hours each night, while the other half stayed up until midnight and slept only five hours. All of the subjects were given access to unlimited amounts of food. During the second week of the study, the roles were switched.
The results of the study showed that the sleep deprived subjects actually had an increase in their metabolism, burning an extra 111 calories. However, it soon caught up with them as they ended up eating significantly more than those in the study who were allowed a good night of rest. When the researchers reversed the roles and allowed the sleep deprived subjects to get more sleep, they began to lose some of the weight they had gained during their first, sleep-deprived week. [source]
The Annals of Internal Medicine Report

Last fall, The Annals of Internal Medicine reported on a study by University of Chicago researchers, who found that lack of sleep alters the biology of fat cells. In the small study — just seven healthy volunteers — the researchers tracked the changes that occurred when subjects moved from 8.5 hours of sleep to just 4.5 hours.
After four nights of less sleep, their fat cells were less sensitive to insulin, a metabolic change associated with both diabetes and obesity. According to Matthew Brady, an associate professor of medicine at the University of Chicago and the senior author on the study, the lack of sleep aged the metabolic structure of fat cells by about 20 years. [source]
7 Positive Effects of Healthy Sleep Habits
Increases your mental and physical alertness
Perform better at your job; drive safer when you’re on the road. According to the National Highway Traffic Safety Administration (NHTSA), in 2009, the highest number of fatal, single-car-run-off-the-road-accidents were due to sleep deprivation!
Improves your mood
It shouldn’t come as a surprise that well rested people tend to be happier.
Increases your energy
When you are well rested, you tend to have more energy – another no-brainer.
Keeps your heart healthy
Studies have linked sleep with your body’s blood vessels. The more sleep you get, the better your blood pressure and cholesterol tend to be, which are two risk factors for heart disease. Therefore, try to aim for 7-9 hours of sleep each night.
Reduces stress
When your body is sleep deprived, it produces stress hormones, which (unfortunately) causes an increase in blood pressure and cortisol. This can put you at an increased risk for heart attack, stroke; and ironically, it makes it harder for you to fall asleep.
Reduces inflammation
People who get 6 hours of sleep or less per night have higher blood levels of inflammatory proteins than those who get more sleep.
May help you lose weight
Sleep and metabolism are controlled by the same sections of your brain. When you are sleepy, certain hormones are at work, and when you are sleep deprived, these hormones may also be at work to drive your appetite.

Ways to Improve Your Sleep
To help improve your sleep, try some of the following tips. Have additional advice that you’d like to share? We’d love to hear it in the comments section!
- Avoid alcohol and caffeine at least 3 hours prior to bedtime.
- Sleep in a dark room.
- Establish a healthy sleep routine and maintain it.
- Exercise regularly at least 5 days a week.
- Avoid high-tech distractions in the bedroom.
- Snack healthy at night.
- Do 10 minutes of foam rolling before bed, focusing on the legs and upper back.
I love sleep. My life has the tendency to fall apart when I’m awake, you know? – Ernest Hemingway
References:
- Bouchez, C. The dream diet: Losing weight while you sleep. WebMd. Retrieved from: http://www.webmd.com/diet/features/lose-weight-while-sleeping
- Breus, M. (June 2011). How sleep affects weight loss. The Huffington Post. Retrieved from: http://www.huffingtonpost.com/dr-michael-j-breus/sleep-weight-loss_b_881186.html
- Harvard School of Public Health. The Obesity Prevention Source: Sleep. Retrieved from: http://www.hsph.harvard.edu/obesity-prevention-source/obesity-causes/sleep-and-obesity/
- Mann, D. Coping with excessive sleepiness. WebMd. Retrieved from: http://www.webmd.com/sleep-disorders/excessive-sleepiness-10/lack-of-sleep-weight-gain
- Parker-Pope. T. (March 2013). Lost sleep can lead to weight gain. New York Times. Retrieved from: http://well.blogs.nytimes.com/2013/03/18/lost-sleep-can-lead-to-weight-gain/
- Patel SR, Malhotra A, White DP, Gottlieb DJ, Hu FB. Association between reduced sleep and weight gain in women. Am J Epidemiol. 2006; 164:947-54.
Further Reading:
- Breus, M. (November 2011). The sleep-weight connection: gender matters. The Huffington Post. Retrieved from: http://www.huffingtonpost.com/dr-michael-j-breus/sleep-weight-gain_b_1069409.html