“Look, here’s the bottom line: everything you do, you do better with sleep.” That’s one of the driving principles behind the work of Dr. Michael Breus, aka “The Sleep Doctor.” As a clinical psychologist, Diplomat of the American Board of Sleep Medicine, and Fellow of the American Academy of Sleep Medicine, Dr. Breus has spent his life researching the topic of sleep and helping countless people improve their health through better sleep. Read on to learn some of his powerful sleep insights, including how to determine your perfect amount of sleep, how “sleep drive” impacts your sleep quality, the relationship between food and sleep, and more.
*This is a short clip of our interview with Dr. Michael Breus. Click here to watch the whole thing!*
What’s The Perfect Amount of Sleep?
Dr. Breus doesn’t mince words when it comes to the importance of quality rest. “Sleep affects every organ system, every disease state,” he says. “Everything that you can do, you can do better with a good night’s rest.” When you don’t get enough sleep — or sleep a lot but poorly — there’s a cascade of consequences for your health. There are cognitive problems like worsened memory and physical problems like slowed reaction times; your emotions become more volatile and you’re more easily irritated or angered; things literally start to hurt, as sleep deprivation leads to increased pain perception.
All of this means that getting adequate quality sleep is a non-negotiable for your health. But just how much sleep is that? Most of us have internalized the idea that the perfect amount of sleep is eight hours, but Dr. Breus says that number is an oversimplification, and we shouldn’t put too much stock in it. As he explains, everyone’s sleep needs are unique, so there’s no set amount of sleep. “Everyone’s sleep needs are individual,” he says. “So once you know how much sleep you need, if you don’t get that, that’s when bad things begin to happen.”
Thankfully, Dr. Breus has developed a simple process for determining the perfect amount of sleep for you. He explains that there are five stages of sleep — stage one, stage two, stage three, stage four, and REM (rapid eye movement) sleep — and it takes approximately 90 minutes to complete one sleep cycle. Each night, the average adult goes through five different 90-minute cycles. Doing the math, that works out to 450 minutes of sleep, or 7.5 hours.
Of course, because not everyone’s sleep cycle is exactly 90 minutes, and because some of us might need more or fewer sleep cycles per night, this number is just a ballpark. Still, Dr. Breus says you can use it as a tool to determine your perfect amount of sleep. To do that, first you need to establish what he calls your “socially determined wake up time.” This is the time by which you need to be up each morning, whether it’s to go to work or make breakfast for the kids or take out the dog.
Then, simply work backward 7.5 hours from that wake up time, and make that your new bedtime for 10 days. After 10 days, assess and adjust if necessary. Are you waking up just before your alarm clock? Then you’ve found your perfect amount of sleep and the right sleep schedule! If you’re waking up long before your alarm goes off, then you likely don’t need a full 7.5 hours of sleep, so you can go to bed later. If you’re still dead asleep when your alarm goes up, then you need more sleep, so try pushing your bedtime earlier (try one more sleep cycle, so 9 hours of sleep). After some experimentation, you should be able to fall into a sleep rhythm that works with your life and leaves you rested.
Sleep Rhythm and Sleep Drive: The Two Keys to Quality Sleep
For some people, it’s not as simple as that. That’s because there are other factors involved in sleep besides the number of minutes you need. Two of the most important factors, Dr. Breus explains, are sleep rhythm and sleep drive.
Sleep rhythm, as the name suggests, is related to your individual circadian rhythm, or the innate dip and rise of your energy levels throughout a 24-hour period. Each of us has genetically predetermined sleep rhythm, or chronotype, and these chronotypes fall into four different categories:
Bear: People with a bear chronotype have sleep rhythms that fall in line with the movement of the sun. They tend to wake and fall asleep easily, and are prone to a post-lunch energy dip.
Wolf: People with a wolf chronotype are night owls. They like to rise late and struggle with early wake-ups, and are most productive after four in the afternoon.
Lion: People with lion chronotypes are morning people. They like to wake up and go to bed early, and are most productive before noon.
Dolphin: Dolphin chronotypes are quite sensitive to environmental changes and other disturbances around them, and so have trouble following a consistent sleep schedule. For many, this means not getting enough sleep.
There are various different ways to figure out your sleep rhythm, or chronotype, including at-home genetic testing kits or taking this quiz created by Dr. Breus. “Once you know your chronotype,” says Dr. Breus, “you can sleep in line with that schedule, and that’s best.” Not all of us have the flexibility to align our sleep schedule with our chronotype, but — especially with the rise of work-from-home arrangements — you probably have some wiggle room to make things better fit your natural rhythm.
However, even if you can’t align your sleep schedule with your chronotype, the most important thing is to make sure you wake up and go to sleep at the same time every single day. According to Dr. Breus, this is one of the most powerful things you can do to improve your sleep quality, and thus your overall health. He says that if people only took away one piece of advice from his interview, he would want it to be, “wake up at the same time every day, including the weekends. Every day. It’s just how your body works best.”
Another thing to consider is the way that external factors affect your natural sleep rhythm. Doing things like eating or exercising too close to bed, consuming too much caffeine, or exposing your eyes to blue light near bedtime can all convey confusing messages to your body that hinder sleep. Dr. Breus highly recommends blue light blocking glasses as a way to avoid the negative impact of blue light on sleep, while still allowing you to have some relaxing screen time in the evening.
Then there’s sleep drive, which is your desire or need for sleep. Dr. Breus likens it to hunger, in that just as hunger dissipates when you eat, sleep drive dissipates when you sleep. When your sleep drive is high, you feel sleepy, and when your sleep drive is low, you feel wide awake. For most people, your sleep drive increases throughout the day as you get further and further from the last time you slept, so by the time you go to bed at night, it’s reached its peak.
But, as the epidemic of sleep disorders suggests, it doesn’t always work that way. Those with insomnia, for instance, have a lower sleep drive at night, which makes it nearly impossible to fall asleep. This is why Dr. Breus recommends strongly against naps for those with sleep issues, because napping will lower your sleep drive, making it more difficult to get the nighttime sleep your body needs (think of it like spoiling your appetite by eating a big snack before dinner).
The differences between sleep drive and sleep rhythm also explain why Dr. Breus advises against melatonin for sleep issues. Melatonin, he says, only affects sleep rhythm, and not sleep drive. In other words, it tells your body that it’s bedtime, but doesn’t actually make you sleepy if your sleep drive is low for whatever reason. For resetting your circadian rhythm after travel or other external sleep disturbances, it can be effective in the short-term, but it’s by no means a fix for insomnia.
The Relationship Between Food and Sleep
At WellBe, we’re highly attuned to the way that diet impacts every aspect of your health, so it should come as no surprise that we talked to Dr. Breus about the relationship between food and sleep. But as he explained, when it comes to your sleep, it’s actually when you eat — not what you eat — that matters most.
The American tendency is to have our largest meal at the end of the day, but turns out that this is a poor choice both for your digestion and for your sleep. “Your body was just not meant to digest food lying down,” Dr. Breus says. To make sure that your digestion doesn’t disrupt your sleep (or that sleep doesn’t hinder digestion), he recommends finishing your last meal two to three hours before you go to bed.
But he also cautions against eating too little at night, as that could also have a disruptive effect on sleep for some people. For one thing, if you’re hungry when you crawl into bed, you’re not likely to be able to go to sleep. And even if you do fall asleep, if you didn’t go to bed with adequate fuel in your body, it could result in unwanted nighttime wakings.
“Blood sugar issues can wake people up at night,” says Dr. Breus. So if someone eats dinner on the early side, say around 6:30, they may wake up at 2:30 or so because of a blood sugar dip. “When your brain doesn’t have enough blood sugar in it, it sends a signal out to increase cortisol to get you to go find food. Cortisol does not mix well with sleep.”
To combat these issues, he suggests not eating dinner too early, or having a snack before bed if you must eat dinner long before bedtime. In terms of what to eat, he says that the ideal snack is around 250 calories, and about 75% carbohydrates and 25% protein. This is because carbohydrates increase serotonin, the calming hormone, which helps lower cortisol levels. Good nighttime snack options include things like no-added sugar toast with no-added-sugar nut butter or some no-added-sugar cereal with unsweetened non-dairy milk. For those who still struggle with blood sugar-related wakings — or for those who are fasting or otherwise trying to avoid nighttime snacks — he suggests guava leaf tea, which has been shown to help keep blood sugar levels stable all night long.
In terms of what not to eat, Dr. Breus says that sugar is the biggest offender for sleep disruption, and that spicy foods can cause indigestion for some people. But generally, he doesn’t see diet having a dramatic effect on people’s sleep.
The WellBe Takeaway: Using Sleep Insights to Power Your Health
We’ve long known that sleep is an essential pillar of health, and our interview with Dr. Michael Breus confirmed that belief. Still, sleep is a complex topic, and it doesn’t always come easily to many of us. As Dr. Breus illustrated, though, a little bit of knowledge can go a long way toward improving your sleep, whether you identify as having sleep issues or not. Here’s what to remember about sleep and your health:
Sleep is central to your health. It affects all of your bodily processes, as well as your disease response, not to mention your emotional, cognitive, and psychological health.
It takes the average adult 90 minutes to cycle through one sleep cycle, which includes five stages of sleep. During any given night, most adults need five sleep cycles. This works out to 7.5 hours of sleep, though this is a ballpark estimate and will vary from person to person.
To calculate your perfect amount of sleep, as well as when to get it, work backward from the time you need to wake up. Turn the light out 7.5 hours before that time, and adjust your bedtime earlier or later based on how you feel when your alarm goes off.
Sleep rhythm is another important factor in sleep. This refers to your individual circadian rhythm, or chronotype, which determines what times of day you feel the sleepiest and when you have the most energy. You can take this quiz to determine your chronotype.
Sleep drive refers to how sleepy you are. Think of it like this: sleep drive is to sleep as hunger is to eating. So if you’re struggling to sleep at night, make sure that you’re not sabotaging your sleep drive with naps or other sleepiness-suppressing activities.
When it comes to food and sleep, the most important thing to consider is when you eat, not what you eat. Dr. Breus recommends having your last meal two to three hours before bed, and having a small snack closer to bed if you eat dinner early. This latter part is because, if you don’t go to bed with adequate fuel, you may be woken up in the middle of the night when your blood sugar dips.
The ideal food to eat before bed is high in carbohydrates, which increase serotonin, the calming hormone. Foods to avoid include sugar and spicy foods.