We know our Performance Inspired readers have that hustle hard mentality: work hard, train hard, eat clean. Oh and make time for family and your social life, of course. Do you often find that sleep takes a back seat to all of the other things you need to get done during the day?
While it may seem beneficial to wake up a few hours earlier to squeeze in a training session before work or stay up late to meal prep for the week, sacrificing your sleep can have a negative impact on almost every area of your life. It can make you irritable, decrease your level of focus, cause headaches, reduce your ability to retain information, and derail your fitness progress. Yes, that’s correct, getting an insufficient amount of sleep can actually lead to weight gain. Read on to learn how sleep deprivation plays a role in weight gain.
Sleep deprivation = slow metabolism
Sleep plays an important role in the maintenance of metabolic homeostasis, which means how your body balances energy intake (calories from food) and energy expenditure (calories burned). When you eat, the body breaks down the food into glucose and uses it as a form of energy throughout the day. The more energy you expend the more glucose you burn off.
A study published in the Lancet examined the effects of recurrent partial sleep deprivation on glucose metabolism. In this study, healthy young men were first subjected to 6 nights of 4 hours in bed (“sleep debt”) followed by 7 nights of 12 hours in bed (“sleep recovery”). The subjects ate identical carbohydrate-rich meals and were at continuous bed rest on the last two days of each condition. Intravenous glucose tolerance tests revealed that the rate of glucose clearance during the initial phase of the test (“sleep debt”) was 40% lower, glucose effectiveness was 30% lower, and the acute insulin response to glucose was also 30% lower. (Sleep Med Rev., 2007)
A proposed reason for this slower metabolism has to do with how your brain perceives a lack of sleep. According to Dr. Michael Breus, Ph.D, when you are lacking quality shut-eye time, your brain dictates survival mode and triggers conservation of resources. Survival mode ensues regardless of the reason for your sleep deprivation. Your brain simply doesn’t understand why it is still awake. It can’t comprehend the difference between staying up all night to watch a few more episodes of your favorite TV show and staying up all night to ward off danger. Due to this, the brain slows metabolism so that more of the calories you take in are stored as fat instead of being put to immediate use. Over time, this can lead to weight gain.
Sleep deprivation can make your hormones out of whack
Since insufficient sleep causes your body to go into survival mode, the levels of cortisol, the “stress hormone” will begin to rise. Cortisol, a glucocorticoid, is produced by your adrenal glands and is released in response to stress and low blood-glucose concentration. Chronic sleep deprivation can cause consistently high levels of cortisol, which causes a greater release of insulin into the bloodstream. As a result, your blood glucose level drops thus causing you to crave sugary, fatty foods.
Another way that sleep deprivation plays a role in weight gain has to do with your
“hunger hormones”. These hormones are ghrelin and leptin, which signal to your brain when you are hungry and when you are full, respectively.
The Wisconsin Sleep Cohort Study observed the relationship between sleep deprivation and the hunger hormones on 1,024 volunteers. The study found that a short amount of sleep (5 hours versus 8 hours) was associated with a 15.5% lower level of leptin and a 14.9% higher level of ghrelin. From these results it’s clear that sleep deprivation plays a role in weight gain by causing us to feel hungry more often and feel satiated after eating, less often.
Sleep deprivation leads to poor lifestyle choices
We all know that after a sleepless night we are more likely to reach for a large cup of coffee and sugary pastry than a healthy breakfast smoothie full of fresh fruits and greens. Plus, that exhaustion stays with us throughout the day (unless you’re lucky enough to squeeze in a nap) which makes the couch seem so much more appealing than the gym after a long day at work.
The reason we crave unhealthy food choices when we are sleep deprived is once again due to the brain’s entry into survival mode. In this mode, the brain seeks foods that will produce a calming effect, such as foods high in carbs, sugar, and the bad kind of fat. So if we know that we shouldn’t be eating these unhealthy foods, why does the brain feel calm after eating them?
Dr. Michael Breus, PhD, explains that these types of foods lead to a higher release of serotonin in your brain. Serotonin, or 5-hydroxytryptamine (5-HT), is a monoamine neurotransmitter that exhibits a calming effect as well as contributes to well-being and happiness. This is why these unhealthy food choices are called “comfort foods”; they are not only satisfying to your taste buds, but to your brain chemistry as well.
In addition to craving comfort foods when we are sleep deprived, a study published in The Journal of Clinical Endocrinology and Metabolism found that insufficient sleep leads to the desire to consume more food than we would after a full night’s rest. This study examined twelve male subjects of normal weight in two scenarios: one being after a night of total sleep deprivation and the other after a full night’s rest. The study reported that total sleep deprivation was associated with increased brain activation in response to food images, independent of calorie content and prescan hunger ratings.The study concluded that acute sleep loss drives people to consume food due to enhanced hedonic (pleasurable) stimulus processing in the brain. (J Clin Endocrinol Metab, 2012) It’s clear that sleep deprivation plays a role in weight gain due to low energy levels that often lead to poor lifestyle choices.
Sleep to lose weight
Don’t let sleep (or lack thereof) derail your weight loss and fitness goals! Research has proven that sleep deprivation plays a role in weight gain, so it’s evident that sleep should be prioritized along with diet and exercise to maintain a healthy lifestyle.