If you know me, then you know that there is very little I am willing to sacrifice sleep for, but I still have those nights where I catch myself starting another episode of some Netflix original instead of hitting the sack. We all have different reasons for why we skimp on sleep, but one thing is for sure – sleep deprivation greatly effects our health. So, no, this post is not about the detriments of sitting or mindlessly snacking, but sleep!
You have probably heard that you should get 7-8 hours of sleep a night, but do you do it? According to the Gallup survey, 40% of Americans get less than 7 hours of sleep a night.
You may be wondering if you need 7-8 hours a night? While the magical number does slightly, sleep researchers agree that adults should get 7-9 hours of sleep a night for optimal health. In fact, those restricted to as much as 6 hours a night can have large declines in cognitive behavior. Which means, according to that Gallup survey, 40% of Americans are walking around at a diminished cognitive level.
The study found that those who got 6 or less hours a night of sleep for two weeks tested similarly on cognitive tests as someone who had two nights of total sleep deprivation. Another study found that the impairment of performance caused by 20-25 hours of sleeplessness is comparable to that of someone with a 0.10% blood alcohol concentration. These tested cognitive functions include memory, focus, and reaction time. Wow!
So why are so many Americans subjecting themselves to less than 7 hours of sleep a night? It may be that individuals do not realize the detriments of less sleep. The above mentioned study also found that the participants who suffered cognitive decline at 6 hours of sleep a night were not conscious of their cognitive decline. Imagine that, if you are one of those people getting less than 7 hours a sleep a night you maybe sacrificing cognitive potential and be putting yourself at higher risk of accidents – especially on the road.
So, besides loss of memory, lack of focus, and declined reaction time why else should we get more sleep? Sleep research has also found sleep deprivation to be correlated with unemployment, lower income, Alzheimer's disease, weight gain, depression, lower immunity, prolonged physical recovery, and a shorter lifespan. To cover all of these subjects, this post would go on way longer then you are probably willing to read. So, I am going to focus on one of the topics that is most relevant to a lot of my clients – weight gain.
Sleep and Weight Loss
There are many contributing factors as to why sleep deprivation causes weight gain but research shows that it may be due to changes in a variety of hormones including ghrelin, leptin, cortisol and insulin.
Two of these hormones, ghrelin and leptin, are the bodies hormones for regulating hunger. Ghrelin signals your brain that it’s time to eat. When you’re sleep-deprived, your body makes more ghrelin. Leptin, on the other hand, cues your brain to put the fork down. When you’re not getting enough sleep, leptin levels plummet, signaling your brain to eat more food. In short, insufficient sleep impacts your hunger and fullness hormones telling your body to eat more food.
In addition to a larger appetite, a sleep deprived body does not burn fat the same. A lab study restricted dieters to 5.5 hours of sleep over a 14-day period and found that the amount of weight they lost from fat dropped by 55%, even though their calories stayed equal. They felt hungrier and less satisfied after meals, and their energy was zapped.
This decrease in fat loss is believed to be due to insulin sensitivity. Researchers from the University of Chicago found that insufficient sleep decreased the body’s ability to process insulin resulting in more than a 30% drop in insulin sensitivity in sleep deprived individuals. When your body doesn't respond properly to insulin, a hormone needed to change sugar, starches, and other food into energy, your body has trouble processing these molecules and ends up storing them as fat.
While these studies did restrict participants to a dramatic 5.5 hours and 4.5 hours of sleep a night. Another study found that “as little as 30 minutes a day sleep debt can have significant effects on obesity and insulin resistance.”
Another hormone affected by sleep is the stress hormone cortisol. The stress hormone, cortisol, leads to food cravings, and probably not for vegetables. According to Dr. Breus, author of The Sleep Doctor's Diet Plan: Lose Weight through Better Sleep, “when you’re stressed, your body tries to produce serotonin to calm you down. The easiest way to do that is by eating high-fat, high-carb foods that produce a neurochemical reaction.” So basically, when you’re stressed and you’re craving chips or a tub of ice-cream, that’s your bodies way of trying to make yourself feel better.
So, to sum this all up: sleep deprivation is not helping you make good decisions or shed those extra pounds.
How to Get More and Better Sleep.
Turn out the lights. Darkness cues your body to release the natural sleep hormone melatonin, while light suppresses it.
Limit exposure to white light after sunset. Exposure to the light of 'white' LED bulbs appears to suppress melatonin five times more than exposure to the light given off by an orange-yellow light. Yes. this means, shut down your computer, cell phone, and TV at least an hour before bed. At minimum, turn night mode on so that your devices emit less blue light.
Save your bedroom for sleep and sex. Our brains are highly associative. So, don’t use the bed for work or entertainment or that’s what your brain will want to do when it is time for bed.
Create a bedtime ritual. It's not the time to tackle big issues. Instead, take a warm bath, meditate, listen to a podcast, or read. And do this with dim yellow light.
Stick to a schedule, waking up and retiring at the same time every day, including the weekends improves our quality of sleep. Research shows that we can’t make up all our weekday sleep deprivation by sleeping-in on the weekends. Think of sleep loss as high interest debt – it accumulates faster then you can pay it off.
Avoid alcohol before bed and stay clear of caffeine 4-6 hours before bed. This includes soda, tea, coffee, and chocolate.
Last but not least, get regular exercise! Yes, our bodies like to move. And after a good days work we usually get better zzz’s.
To learn more about sleep listen to this recent interview by Terry Gross with Dr. Matthew Walker – a sleep researcher and author of Why we Sleep: Unlocking the Power of Sleep and Dreams.