by Dave Asprey
But then you toss and turn all night. You wake up with dry mouth, which means that you’ve been sleeping with your mouth open. Clearly you were snoring. In the morning, as you sip your coffee and try to arouse your mental acuity, you find yourself mildly exhausted. What went wrong?
First, your stomach was still somewhat full at bedtime. A full belly means that your diaphragm has less room to expand and contract (or, as you would more commonly say, “to rise and fall”). Your internal organs were crammed tightly into your abdominal cavity, pressed against one another like commuters on a rush-hour subway. A full stomach presses upward on the diaphragm, which in turn puts pressure on your lungs, not allowing them to expand completely. There is some evidence that sleeping on your left side can reduce pressure on the stomach, which is a good habit when you go to sleep on a full stomach. The rest of the time, sleeping on your right side is better for your heart.
Second, there’s a good chance that you ate something you’re sensitive to—even if you didn’t know it—which triggered acid reflux or even anxiety. Those foods can relax the valve separating the esophagus and stomach. Acidic foods irritate the throat lining, leading to acid reflux. This is the condition that occurs when foods enter the stomach and then travel backward up the esophagus into the airway. (Flux is the Latin word for “flowing,” and reflux is a flow going in the wrong direction.) Acid reflux can be severe enough to cause postnasal drip, another leading cause of snoring. This is excess mucus buildup on the back of the nose and throat. Dairy products, wheat, and alcohol are common triggers of mucus formation, too.
A late meal leads to acid reflux, which leads to postnasal drip, all of which then leads to coughing, airway irritation, and inflammation. Coughing is another leading cause of snoring, so it all adds up. Bad food plus bad timing equals bad sleep.
You may think that you had no control over all the factors that led to your lousy night’s sleep and groggy morning—but of course you did. Perhaps you could have set the time of the dinner. Definitely you had control over what you ordered (wine? carbs? cheese sticks?). And definitely—definitely—you had control over when you went to bed. In this case, it would have been a smart trade to go to bed a little later, sacrificing some of your night’s sleep length in exchange for better sleep quality: less sleep overall, but higher quality sleep. It’s a good trade. You could also have taken a sleep-inducing supplement, such as melatonin, magnesium, or 5-hydroxytryptophan (5-HTP, also known as oxitriptan), to help.
Managing a more serious problem such as chronic obstructive sleep apnea is more difficult. This potentially fatal sleep disruption occurs when the soft tissues in the throat relax completely, blocking your airway. Sufferers wake up dozens of times a night gasping or choking and typically snore loudly enough that their partners cannot sleep. Wall-rattling snoring is the opposite of sexy, and the inevitable requests that the snorer sleep in another room can put quite a strain on a relationship. Adding insult to injury, one of sleep apnea’s primary side effects—in addition to high blood pressure and nighttime sweating—is loss of libido.
Fasting alone can’t completely fix sleep apnea. If you suffer from apnea, you need to begin by doing a sleep study with a reputable lab and getting treatment with a bite guard that helps your jaw stay forward or perhaps a CPAP machine. But to the extent that fasting can lead to weight loss, it can be a significant help. The number one cause of sleep apnea is being overweight, perhaps because of fatty deposits that accumulate in the upper airways. A recent study at the Perelman School of Medicine at the University of Pennsylvania uncovered a related risk factor: people who have excess tongue fat suffer disproportionately from sleep apnea.11 There’s no way to do liposuction of the tongue, unfortunately. Some research suggests that dronabinol, a cannabinoid drug, taken before bedtime could help. What clearly does work, though, is losing weight. A 10 percent reduction in body weight is associated with a 20 percent decrease in apnea symptoms, researchers have found.12 Fasting to the rescue again!
Restless legs syndrome is another common sleep disorder, even though it is much less widely discussed than apnea. Also known as Willis-Ekbom disease, restless legs syndrome affects some 5 percent of the general population and 10 percent of people over the age of sixty-five.13 As the name suggests, this syndrome leads to uncontrollable leg movements. This occurs most often at night as a series of little muscle spasms and can significantly affect quality of rest. Many people aren’t even aware that they have it; all they know is that they tend to have low-quality sleep and frequently wake up feeling tired.
Although the connection is not as definitive as it is with apnea, restless legs syndrome appears to correlate with obesity.14 There’s also some evidence that restless legs syndrome may be brought on by mild neurological inflammation and nervous system disruption by toxins, heavy metals, environmental mold, and eating foods to which one is allergic. If you have restless legs, there’s an easy way to tell if toxins from your diet are causing it: run a fasting experiment. Fast for a day, and go to sleep. If your restless legs are magically cured, it’s likely that something in your diet is causing them. I used to have restless legs intermittently and discovered that by removing foods I was sensitive to, such as those high in histamine, lectins, and particularly mold toxins, my restless legs went away. Fasting will tell you if your restless legs are due to a food issue or something else.
YOU DON’T NEED A DRINK
Speaking of toxins, any meaningful program to improve your quality of sleep and exert self-control over your diet has to deal with the toxin that so many of us knowingly and eagerly consume.
Alcohol is fun to drink, and it is absolutely, positively bad for you. Even a glass of wine several nights a week will destroy your sleep quality. You will see this as soon as you buy a sleep-tracking ring or wrist monitor; it will be blindingly obvious, no matter how much you don’t want it to be true. Dr. Daniel Amen, a well-known psychiatrist and brain-health expert, has published 3D scans of brains of people who drink one glass of wine several nights a week, showing obvious metabolic brain dysfunctions as a result.
That said, drinking alcohol is fun as long as you do it with your eyes open. If you’re going to drink, drink the most expensive stuff: you’ll get the most enjoyment, and you’ll end up drinking less. Be aware that alcohol breaks your fast and that your blood sugar level will likely be less stable the following day. You will need the intermittent fast even more the next morning, but it will be harder than usual to do. We all have our indulgences, though, so feel free to consume alcohol in moderation. The goal here is not misery, nor is it asceticism.
Perhaps the most surprising dietary aspect of alcohol is that it triggers a stress response that causes the body to secrete protective molecules called heat shock proteins. If you want to impress your friends with an argument for drinking alcohol, here it is: alcohol causes a short-term increase in body temperature and raises your heat shock proteins. That’s why snow rescue dogs used to carry a little cask of brandy on their collars—so that hypothermic people could get a quick burst of heat from drinking it. That effect may explain the positive correlation between light to moderate alcohol intake and the risk of cardiovascular mortality seen in the landmark Zutphen Study, which tracked the health of 1,373 men over a period of forty years.15 Unfortunately, the downside is still higher than the upside, and you can protect your heart a lot more effectively simply by fasting. Sorry.
While you’re fasting or just lowering inflammation, you can choose alcohols that are lower in toxins and lower in sugar. At daveasprey.com/alcohol there is a full-page alcohol road map to help you select the best alcohol for fasting or just staying alive longer. It will help you drink intelligently. Distilled beverages without additives—vodka, tequila, and whiskey—are the best by far. Dry white French wine is your next best bet. After that, red wine. The worst of all is beer.
I get it: alcohol brings people a lot of pleasure, and it’s deeply embedded in our social traditions. I just see an awful lot of people drinking in ways that don�
��t take into account the true effects of alcohol. In particular, keep in mind this crucial fact: alcohol is not a sleep aid.
Contrary to the old tradition of having a “nightcap,” drinking alcohol in the evening actually increases sleep interruption. True, it helps you fall asleep faster, but the type of sleep one experiences after that nightcap is not the deep, rapid eye movement (REM) sleep that promotes dreams and restores our brains. Then, when the alcohol wears off in the middle of the night, it ends up disrupting your sleep cycle. Like eating a large meal too close to bedtime, drinking alcohol causes sleep disruptions as the soft tissue of the throat becomes relaxed and possibly even completely closed. Drinking alcohol too close to bedtime can lead to sleepwalking, sleep talking, and memory problems.
There are no hard-and-fast rules about drinking while intermittent fasting, but always make sure to fill your stomach first. In other words, don’t drink your calories. Also, since alcohol and fasting both place greater fluid needs on the body, make sure to drink plenty of water throughout both the fasting and nonfasting portions of your day. It’s all about balance. If you’re going to make fasting part of your lifestyle, avoid being extreme. Drink and eat in moderation, and don’t beat yourself up if you’re not perfect.
It’s worth mentioning that alcohol is not a sex aid, either. If you want a better sex life, you’re much more likely to get it by improving the quality of your sleep and embracing intermittent fasting. In a long-term study on fasting at the Pennington Biomedical Research Center in Baton Rouge, Louisiana, 218 people of a healthy weight (not obese or suffering from an eating disorder) agreed to reduce their caloric intake by 25 percent over a period of two years. Those who chose fasting as their means of caloric reduction reported a typical weight loss of about 16.5 pounds. In addition, the subjects said they slept better, felt happier, and enjoyed a better sex life.16
The key here is food choice while fasting. If you eat a diet high in protein and healthy fat during times of nonfasting, your sex drive will likely increase. If your diet has a deficit of healthy protein and fats—or if it is, in fact, that Coke and Doritos diet we discussed before—you may still encounter issues in the bedroom. As I often say, intermittent fasting will benefit you regardless of how you eat—but there are limits to what it can do.
Intermittent fasting has a powerful impact on testosterone level, raising it by 180 percent, and increasing luteinizing hormone, a testosterone precursor, by 67 percent. But longer fasting has the opposite effect, as a three-day or longer fast can lower it.17 In addition, the reduced insulin level we discussed earlier, which is one of the key benefits of fasting, boosts testosterone level. This has dramatic effects on healthy erectile function. Another beautiful study conducted during the Muslim holy month of Ramadan showed that intermittent fasting raises the level of a hormone called adiponectin that makes you more insulin sensitive, which raises your testosterone level.18
There are some complicating factors that come with intermittent fasting, however. Ghrelin, the “hunger hormone” that stimulates appetite, also motivates us to find a partner and have sex. A higher level of ghrelin generally correlates with a higher sex drive; a lower level corresponds to diminished libido—in lab mice, at least. Adjusting your fast to reduce ghrelin-induced feelings of hunger could therefore tamp down some of your sex drive. Although few men or women report a reduction in desire due to intermittent fasting, most will feel less interest during multiday fasts.
Moving beyond physiology, one of the greatest influences on libido and sex appeal is confidence. Holding on to too much body fat lowers your testosterone level and decreases your libido, and it unquestionably eats away at your self-confidence. My old 300-pound self can attest to that. A pattern of fasting, sleep, and proper circadian health will reduce body fat, raise testosterone and human growth hormone levels, and boost sex drive.
What we all want, in the end, is to feel good about ourselves. We want to be in control. We want to know that we’re experiencing our full potential or at least working our way there. Fasting and sleep, together, can get us there.
YOUR SLEEP MISSION
Even if you pay attention to your diet, cut out alcohol, give yourself some space from electronic devices, and attend to all the other habits of good sleep hygiene, sometimes you will still have a restless night. That’s completely normal. With sleep, as with fasting, meaningful change and improvement don’t happen instantly. You also have a real life with friends, family, work, and many other potential sources of worry and distraction. Give yourself time to adjust. Setting your expectations too high can make matters worse by adding to your stress.
Just as we’ve been programmed to believe the feeling that if you don’t eat, you’re going to die of starvation, most people have at some deep unconscious level enough fear of being tired that it causes anxiety. Let’s rethink that. It’s true that food and sleep are both essential, but it’s also true that you’re probably a lot more resilient than you think.
One of the training exercises for Navy SEALs is sleep deprivation: you get ten minutes of sleep, the trainers wake you up, they make you get up and put on a backpack, and then you run. The goal is to make you realize that you can do just fine even if you’re exhausted. The military calls it sleep conditioning: you train your body to perform well in a nonrested state, even when your circadian environment isn’t perfect. Emergency room doctors go through their own version of sleep conditioning. My wife is an ER physician, so I know the process well. Starting with their medical residency, ER doctors endure sleep deprivation until they learn to snap out of sleep and turn on their brain instantly to save a life. It’s not optimal for anyone’s health to endure sleep deprivation over a long period of time (remember, you can die from lack of sleep before you die from lack of food), but the training enables them to develop the confidence to do their job on remarkably little sleep. That reduces their fear of being tired, but unfortunately it also leads to higher error rates in their care. You want your doctors to have healthy circadian rhythms!
That said, you are both the medical savior and the elite soldier in your mission for self-improvement, and you should approach the job with the same kind of self-confidence. Be prepared to experience sleep disruptions, and know that they don’t have to harm you any more than hunger does, at least in the short term. You should expect sleep disruptions in the early days of a prolonged fast. The first time it happens, it might be disorienting. You’re going to wake up tired and feel unsure if you can make it through the day. Your irrational brain won’t believe you when you say that your body will feel supercharged by the release of ketones and enough cortisol and adrenaline very soon—so that you may actually feel as though you’ve been reborn as a higher version of yourself.
Like hunger, sleep interruptions during prolonged fasting can create a stupid worrying voice in your head. Ignore it, or rather master it. It’s okay if you get only four hours of sleep from time to time. I started Bulletproof while working full-time as a vice president at a big company on four hours or less of sleep per night, while also doing intermittent fasting and developing the Bulletproof Diet. I used fasting to help with my sleep deficits, and I used sleep hygiene hacks to keep my circadian rhythm on track as much as I could. All of these tools are available to you, too.
Get a full night’s sleep if you can, and if you can’t, relax and cut yourself a break. You’re working to take better control of yourself, and you will never gain control by screaming and shouting. So when that stupid voice in your head yaps at you—“This is too hard, this is taking too long, I’m too tired, I’m too hungry, this isn’t working”—don’t yap back. Just remember your mission. You’ve got this.
6
Fast for Fitness and Strength
On day three of the vision quest, I awoke still haunted by dreams of snakes. I instinctively searched my body for bites and examined the dusty floor around me, now illuminated by the sharp rays of the morning sun. There were no signs of slithering serpent marks. I was alive and starti
ng to adapt to the sensations of solitude and now strangely reduced hunger. Well, for moments, at least.
From somewhere in my subconscious, I remembered a quote by the Stoic philosopher Marcus Aurelius: “If you are distressed by anything external, the pain is not due to the thing itself, but to your estimate of it; and this you have the power to revoke at any moment.” Marcus Aurelius is better remembered as a Roman emperor who ruled from 161 to 180 CE. In Hollywood’s stylizing imagination, he was the villain in the movie Gladiator. During his time in power, though, he also wrote a series of insightful Stoic essays. They were collected as the masterwork Meditations, which is where I came across that quote.
According to Stoic philosophy, emotions such as fear and envy are false, superficial impressions of the world. A sage (or a shaman?) who has attained moral and intellectual enlightenment should be able to see past them, rendering them impotent. Then that person can directly pursue a life of virtue, the highest form of good and happiness. I wasn’t thinking of myself as particularly virtuous at that moment, but I was feeling the first glimmerings of what it would mean to truly conquer my self-consuming emotions. Unfortunately, I was also still acutely feeling the physical limitations of my body.
By that point, I had shifted into an altered state—in large part because, for the first time in my life, I’d been going without food for an extended period of time. And after all, I was sleeping in a cave used for spiritual ceremonies for centuries if not millennia. If you’ve never before fasted for more than a day, your body will try to inject thoughts of food into your brain ten times a minute, so that if there’s any food nearby you’ll take just one little bite. If your willpower wins out (or if there simply is no food around to tempt you), the body gets really angry. There’s that voice again, booming in your head: “How dare you ignore me! Don’t you know who I am? Think about cake! You’re going to die if I don’t get food. Hey, do you smell brownies?” I remembered that I’d eaten rattlesnake when I was growing up in Albuquerque and that I’d just missed getting to try fried scorpions one time when I was traveling in Beijing. Those would be my only local dining options. I was glad, though, that I hadn’t sneaked that protein bar into my bag. My inner voice would have won.