We do it just about every night, some are better at it and can do it for longer than others... No, not that… sleep! For those who want to slim down, an activity that involves lying down should be one of the things you prioritize during your quest to drop pounds. Indeed, sleep and weight loss goes together like peanut butter and jelly.
And yet it’s surprising how many of us forgo or skimp on this low-effort opportunity to rebuild multiple key components in our cells1, maintain proper immune, molecular and neural function, avoid impaired cognitive and motor function2, and enhance mood, alertness, and physical performance3.
As a society, we get less and less sleep. In 1998 only 35% of Americans were getting eight hours of nightly sleep; by 2005, that number had fallen to 26%4. The National Sleep Foundation updated its shut-eye recommendation for adults to seven to nine hours per night5, acknowledging that duration outside of these bounds could be appropriate for some.
With the popularity of scrolling through TikTok and Instagram near bedtime, catching up on work emails and projects after putting the kids to bed, or sprawling on the couch for a Netflix binge, the percentage of Americans getting enough quality sleep likely continues to decline.
Trading enough-for-you quality sleep for other “productive” and intentionally unproductive activities can not only make you cranky and fatigued the next day, but can also impact your waistline.
Sleep plays a significant role in maintaining a healthy weight. An observational study of over 68,000 nurses (part of the Nurses Health Study), found that participants who slept five hours or less a night were 15% more likely to be obese6 than those sleeping over seven hours. The study also found that short-sleepers had a 30% higher risk of gaining over 30 pounds during the 16-year study.
On the extreme end of the no-sleep spectrum, one study of 28 healthy volunteers kept awake for three to five days showed a change in the participants’ glucose tolerance curve to a prediabetic one with significantly higher glucose values and no hypoglycemic plunge7 after the spike. Granted, you’re probably not planning to skip sleep for four straight days, but it’s fascinating nonetheless to see how quickly severe sleep deprivation can alter a healthy person’s metabolism.
How does less sleep over time affect your metabolism—particularly how your body processes sugar, or glucose, from the foods and drinks you consume? Lab studies of healthy young adults exposed to recurrent partial sleep deprivation showed decreased glucose tolerance and insulin sensitivity8.
Lowered glucose tolerance, insulin sensitivity, and insulin resistance9, as well as less-than-optimal thyroid function10, make it harder to burn fat and lose weight. These issues can occur for a variety of reasons, one of which is insufficient sleep. Poor sleep and a sleep-deprived state alter your body’s ability to manage blood sugar11 the way it should, which can lead to weight gain.
Also at play in the connection between short sleep and weight gain are two key hormones: leptin and ghrelin. Leptin, produced in your body’s fat cells, sends a signal to your brain when you’re full, stopping you from overeating. When you don’t get enough sleep, your body produces less leptin, which could cause you to eat more to feel full.
Lack of sleep also increases the production of the hormone ghrelin, nicknamed “the hunger hormone.” Insufficient sleep causes your stomach to send a signal via ghrelin that you’re hungry12 and… you guessed it, you eat more.
This one-two punch thrown by leptin and ghrelin leads to eating more and gaining weight after poor sleep13.
But don’t stress out if you get one night of bad sleep. One study revealed that sleep loss is associated with activation of the body’s stress system but not sleep loss per se (although leptin levels increased significantly after one night of total sleep loss) may lead to increased hunger and appetite, and hormonal changes14 that can trigger comfort-food cravings and weight gain.
In addition to the impact on your glucose and hormones, sleep loss can make it harder to lose weight because:
One study tested how six hours of sleep versus four hours of sleep impacted snacking behavior. The odds of participants eating a snack on four hours of sleep were significantly greater—and the sleepy noshers opted for a sweet snack16 more often than a savory or “healthy” snack. Talk about a double-whammy to your body’s glucose.
Ward off these weight loss debacles with our tips for getting more and better quality sleep.
According to Matthew Walker’s best-selling book Why We Sleep, stick to a sleep schedule. Go to bed and wake up at the same time each day. As creatures of habit, people have a hard time adjusting to changes in sleep patterns. Sleeping later on weekends won’t fully make up for a lack of sleep during the week and will make it harder to wake up early on Monday morning.
Set an alarm for bedtime. Often we set an alarm for when it’s time to wake up but fail to do so for when it’s time to go to sleep.
If there is only one piece of advice you remember and take from these tips, this should be it.
Sixty to 30 minutes before bedtime, start your wind-down routine. Turn off your TV. Place your smartphone across the room or in another room so you won’t be tempted to check it as you try to fall asleep or in the middle of the night.
Consider reading a bound book or magazine (the old-fashioned way). What you read also makes a difference; stay away from content that activates or disturbs you.
If your mind races and keeps you awake, keep a journal by your bed and:
The presence of light sources during our sleep can disturb our circadian rhythms and keep us from staying asleep. Invest in black-out shades for your windows or in a light-blocking night mask. If you have alarm clocks with bright displays, put them out of sight.
Wear blue-light-blocking glasses at night to dim the impact of light from screens and ambient light, if possible. Turn on night mode on your mobile devices, which dims the intensity of the light emitted by the screen and turns off notification sounds.
Conversely, expose your eyes to bright light—ideally, light from the sun—in the morning shortly after you wake. Avoiding bright light at night and exposing your eyes to bright light in the morning can ensure the proper release of melatonin17, a hormone that controls the sleep-wake cycle.
Hydration is an important part of regulating your glucose and losing weight18 but when you drink—or, rather, stop sipping—can prevent numerous sleep-disrupting trips to the bathroom during the night. Experiment with the best time to stop drinking water before bed to find your best hydration/sleep strategy.
There’s a significant association between sleep and glucose control19. To keep your glucose from spiking overnight, consider these strategies:
Our bodies tend to cool off during the night, which is why warm ambient temperature can disrupt sleep. This 2012 study20 found that your room temperature is one of the most important factors in a good night’s sleep. The optimal room temperature for sleep is 65 degrees.
Partner permitting, lower that thermostat before bedtime or consider investing in a cooling pad or bed fan for your side of the bed.
Another suggestion from Walker’s Why We Sleep: Consider taking a hot bath before bed. It may sound paradoxical, but the drop in body temperature after getting out of the bath may help you feel sleepy, and the bath can help you relax and slow down so you’re more ready to sleep.
Meditation, stretching, or breathwork can help you wind down and signal to your brain that it’s time to relax. Try this mobility flow21 on your bed, this 10-minute evening yoga stretch22, or this 10-minute meditation23 before you sleep.
Even a simple five-minute foam rolling routine before bed not only helps ease sore muscles but also relaxes you enough to ease into sleep. This video provides a quick foam rolling routine24 to work out those kinks and get to sleep.
If you’ve had a poor night of sleep, pay attention to your glucose readings in the morning. Eat the same breakfast you’ve eaten after a night of good sleep. Do you notice higher readings for your breakfast after not sleeping well?
Go back through your daily data in the Signos app and compare how much you ate, what you ate, and your glucose numbers for days after good sleep and poor sleep. Do you notice any trends?