Why Your Ketogenic Diet Isn't Working Part 2: Sleep and Circadian Rhythm

• Athletic performance [4]
• Insulin resistance [5,6]
• Glucose tolerance [7]
• Obesity [8]
• Hunger and satiety hormones [9]
• Gut microbiota [10,11]
• Cognitive and motor performance [12]
• General hormonal balance [13]
• Male and female reproductive hormones [14,15]
• Cortisol production [16]  
• Cardiovascular function and disease risk [17]
• Perceptions of attractiveness [18]
• Mood [19]
• Cancer [20–23]
• Immune function [24]
• Alzheimer's disease [25,26]
• Neurogenesis [27]
• Aging and its associated diseases [28]

And this is by no means a comprehensive list! By the end of this article hopefully it will become clear that sleep is critical to just about every aspect of health [29].

How do I know if I’m getting enough quality sleep?

• You don’t fall asleep the moment your head hits the pillow
• You don’t lay in bed for an hour trying to fall asleep
• You don’t wake up multiple times during the night
• You wake up feeling refreshed (men, testosterone meter points north)
• Your energy level is consistently good throughout the day

Why might you suffer from poor sleep or a disrupted circadian rhythm?

While there are many reasons that you might sleep poorly or have a disrupted circadian rhythm, we’ll focus on the most common culprits in the next section.

Too much light at night and/or lack of light in the morning

Of all the reasons for a disrupted circadian rhythm, this might win the prize for both most common and easiest to fix. Blue light is the kind of light emitted from most electronics and energy-efficient light bulbs. It has a shorter wavelength than something like red or orange light and is therefore considered higher energy. While natural blue light exposure outdoors during day can increase alertness, boost mood, and positively affect sleep quality [30], too much blue light in the evening after the sun goes down suppresses melatonin - a hormone critical to sleep and general health [31,32]. The circadian mismatch we create with artificial light at night and lack of sunlight exposure has been implicated in many chronic diseases [33].

Stress or a general inability to wind down

Stress from the fast-paced life most of us live can manifest itself in many ways. Often times, people find it difficult to wind down at night and once their head hits the pillow, they simply cannot quiet their thoughts. The level of hormones as well as the responsiveness of their target tissues also fluctuate in a circadian manner [34]. Chronic stress, whether that be from kids, work, or training, can result in cortisol dysregulation and feeling “tired and wired” at night. The adrenal glands have their own natural circadian clock, which when dysregulated can cause chronic sleep issues [35]. Additionally, if the body senses low blood glucose during the night, cortisol will get released in order to stimulate glucose production in the liver, bringing blood levels back up to what the body perceives as safe [36]. This drop in blood glucose and subsequent spike in cortisol may be the underlying cause of sleep disturbances for some people, especially those who are under-eating.  

Shift work

Shift work may be one of the worst offenders in disrupting circadian rhythm and has been linked to not only poor performance but also to adverse health outcomes such as metabolic dysfunction, cardiovascular disease, and even cancer [2].

Caffeine too late in the day

We know that caffeine affects sleep and that everyone responds and metabolizes caffeine differently [37]. This is due to a combination of genetics and habitual intake. While some people may be able to drink a cup of coffee at 2pm with no negative effects on sleep, others might need to time caffeine intake earlier in the day. This may be especially pertinent for athletes training in the afternoon or evening and consuming caffeine prior for its ergogenic effects.

Alcohol

Alcohol is one of the most commonly used sleep aids in the world. However, using it as such may not be a smart idea. There is a critical difference between going to sleep and passing out and too much alcohol too late at night can ruin your sleep. Specifically, while a drink or two (or three) might help you fall asleep faster, it will cause more disrupted sleep during the second half of the night [38]. Alcohol may also negatively influence sleep quality by suppressing melatonin secretion and changing core body temperature [39]. In general, one standard drink takes about one hour to metabolize [40], so a good rule of thumb is to stop drinking at least one hour before bed for every glass of alcohol you consume.

Neurotransmitter imbalances

Neurotransmitters are small chemical messengers that help transmit signals throughout the body via the nervous system. Healthy sleep/wake physiology is dependent on balance of specific neurotransmitters. As such, sleep disturbances may be a consequence of neurotransmitter imbalance. For example, depletion of both tryptophan and serotonin can cause sleep disruption [41] and stress of any kind, including overtraining, may contribute to the underlying cause of neurotransmitter depletion and/or imbalance [42]. This is an especially important point to note for athletes partaking in many hours of intense training every week on top of other life stressors and simultaneously suffering from poor sleep.

Your bedroom environment

Trying to get quality sleep in a noisy room with bright street lights peeking through the curtains can be a frustrating endeavor. While there is some debate about whether extraocular light (i.e. light that is not coming through the eyes) has a detrimental effect on sleep, most people anecdotally report sleeping better in a dark room [43–45].

Obstructive sleep apnea

During sleep, the upper airways can become blocked, ultimately reducing or completely stopping airflow. Sleep apnea can cause awakenings throughout the night and lead to poor sleep quality [46]. Risk factors for sleep apnea include alcohol consumption, smoking, and overweight and obesity. Suspiciously high hemoglobin levels can be a clue that obstructive sleep apnea might be an issue. If you think it is, using a simple pulse oximeter is an inexpensive (but imperfect!) self-diagnostic technique before investing in an official sleep study.

Nocturia

Waking up in the middle of the night to use the bathroom may be common, but it’s not normal. There are some simple explanations for why you might be waking up with the urge to urinate such as large quantities of fluid too late in the evening or medications with a diuretic effect. However, there are also some underlying stress pathologies that might be at play. Dysregulation of the renal circadian clocks has been hypothesized to be an underlying cause [47]. Aldosterone, a hormone that helps regulate fluid and mineral balance as well as blood pressure, should be high at night, causing retention of sodium and fluid. If aldosterone is too low, you might wake up in the middle of the night with a full bladder. And to make things worse, sleep deprivation alone can decrease aldosterone secretion at night, making it a vicious cycle [48].

Theoretically, if cortisol spikes while you’re sleeping due to something such as low blood glucose, it will inhibit ACTH, which will cause a subsequent decrease in aldosterone and promote nocturia. Additionally, a sleeping body should produce less urine (i.e. the glomerular filtration rate decreases). If someone is not truly asleep, perhaps for one of the reasons discussed above, your kidneys will continue to produce urine at a waking rate, leading to nocturia.

Now that we’ve covered the most common reasons why people aren’t getting enough sleep, let’s discuss some practical tips to help optimize sleep and circadian rhythm.

How to optimize your sleep and circadian rhythm and get better sleep

Avoid blue light at night

One of the easiest ways to avoid blue light at night is to wear blue-blocking amber-tinted [49,50]. Switching to orange light bulbs and/or candles when the sun goes down is another option. But while amber glasses might help sleep quality, they don’t make you invincible! The brain stimulation you get from simply taking in a lot of information prior to bedtime may also make it difficult to fall asleep. Therefore, it’s best to try to avoid screens altogether. Reading something less stimulating before bed can be a nice way to wind down, but ditch the blue-light emitting eReader and go for a real paper book [51]!

Go outside in the morning

As far as setting your circadian rhythm is concerned, morning sunlight will always trump coffee! Try to get bright (ideally outdoor) light as early in the morning as possible. Not only does light suppress melatonin production, making you feel more awake, but light during the daytime hours improves sleep quality at night [30,52].

Optimize your vitamin D by embracing sunlight

Embracing sunlight will not only jumpstart your circadian clock, but will also help optimize your [53,54]. Despite the fear-mongering tactics used by some industries, there is no need to slather on 50 SPF every time you go outside. In fact, avoidance of sun exposure is a risk factor for all-cause mortality [55]. Furthermore, sunlight may have cardiovascular benefits that go beyond vitamin D [56]. So use a natural sunblock when needed to make sure you don’t burn but don’t be afraid of a little color.

Eat when the sun is up

There are many health benefits of consuming the majority of your calories during the day when the sun is up and you’re active [57]. While people embracing intermittent fasting may find skipping breakfast convenient, ending your meals earlier in the day and eating breakfast in the morning may be the better option for both circadian rhythm entrainment and overall health [58–60]. The body also responds to calories and macronutrients differently depending on the time of day, and despite the popularity of carb-backloading, insulin sensitivity is highest in muscle in the morning [61,62]. There may be situations in which consuming carbs later in the day is a smart strategy, for instance, if you’re training in the evening, trying to boost sleep-promoting neurotransmitters, or just trying to increase carbs and/or calories in general. However, there is also a great deal of science and physiology to support front-loading carbs. Ultimately, when it comes to nutrient timing, everyone needs to do their own n=1 experiment and find what works best for performance and health.

Stop consuming caffeine after 12 pm

As discussed above, having a cup of coffee too late in the afternoon can be partly responsible for that insomnia. For the average person, a good rule of thumb is to stop the caffeine consumption before noon. Depending on your habitual caffeine intake, sensitivity, and genetics, you might need to stop even earlier in the day (or altogether) for optimal sleep, given that the half-life of caffeine can range from 2.5-10 hours [63]. If you start to feel that all-to-familiar afternoon slump come on at the office, skip the caffeine, get up, and move - even if it’s just for a few minutes [64].

Have an evening routine

About one hour before bed, start winding down. Create an evening routine that puts your body into a parasympathetic (i.e. rest and relax) state and try to avoid stimulating activities such as checking social media or email. If falling asleep is a struggle due to a racing mind and thinking about the next day, consider writing a To Do list before bed, which may help decrease the time it takes to fall asleep [65].

Ditch the alarm clock

If your lifestyle allows, try to ditch the alarm clock. Sleep cycles are about 90 minutes on average and waking up in the middle of a cycle will result in less refreshing sleep. Alternatively, you can try a dawn-simulator alarm clock, which may improve alertness and cognitive and physical performance upon waking [66].

If you do wake up in the middle of the night, do yourself a favor and don’t look at the clock! This will help you avoid one of two scenarios:

1. Oh no! It’s 2 am and I’m still awake! (And you continue to lay awake and worry about not sleeping.)

2. It’s 3:45 am and I’ll be getting up soon anyway… (And you just get up and lose out on another precious hour or two of sleep.)

Drink bone broth or chamomile tea

Bone broth has many health benefits, one of which is its high glycine content. Glycine is an amino acid that is lacking from the modern Western diet and has been shown to improve sleep quality [67]. If an evening cup of bone broth isn’t your thing, consider chamomile or [68,69].

Unplug the WiFi and use airplane mode

While the evidence is far from conclusive, electromagnetic radiation may negatively impact circadian rhythm [70]. Some individuals will likely be more sensitive to this than others, however anecdotally, many people report better sleep when they simply unplug the WiFi and put their cell phone on airplane mode at night.  

Install blue light blocking software

Your brain takes in a lot more information that just light to decide whether it’s time to be awake or asleep. For this reason, it’s best to just avoid screens altogether at night, however sometimes work makes that impossible. (Although in reality, there probably isn’t an email that’s so important it can’t wait until the morning. It will be there when you wake up.) This is where f.lux, Iris, Twilight, and iOS Nightshift come in handy. Once installed on your computer or phone, these programs will control the color of your screen according to the time of day, blocking out the blue light when the sun begins to go down. It’s not perfect, but definitely better than staring at a brightly lit screen right before bed.

Don’t bother tracking sleep

The jury is out as to whether sleep trackers and smartphone apps can accurately track sleep [71]. Even more sophisticated devices such as the OURA ring aren’t perfect, at least in the context of tracking deep sleep [72]. Regardless of any data these devices provide, it’s not unusual to feel a concomitant increase in stress and anxiety with their usage. Orthosomnia, the “perfectionistic quest for the ideal sleep in order to optimize daytime function”, is sadly becoming more prevalent, arguably due to increased sleep tracker use [73]. Thus, we encourage people to track the behaviors that lead to good sleep and subjective feelings (overall energy, mood, concentration, performance) rather than sleep itself.

Time your workouts

For the majority of the busy population, the best time to exercise is when you have the time. However if your lifestyle provides you with the luxury to be flexible with your training, consider doing your more intense workouts earlier rather than later in the day. While there are are potential advantages to exercising later in the afternoon, such as peaking of core body temperature and coordination [74], if optimizing sleep is the goal, workouts (especially those that are intense) are better done earlier in the day [75].

Honor seasonality

Just as sleep cycles naturally change with the seasons [76], allow your lifestyle to adapt as well. In the (northern hemisphere) winter when days are shorter and fresh produce is less available, you may feel like going to bed earlier, waking up later, and eating more protein and fat. However in the summer, when days are longer and fresh fruit is abundant, you might enjoy staying up slightly later, waking up earlier, and eating more seasonal carbohydrates. Additionally, melatonin secretion fluctuates with the seasons [77]. This fact may be particularly important because some evidence suggests that it is the onset of melatonin secretion, rather than clock hour, that determines the optimal timing of food [78].

Outsmart jet lag

When traveling across time zones, slowly start adjusting your biological clock a few days before you leave. Adjust the timing of your food and sleep accordingly and strategically use either blue light or amber glasses (depending on which direction you travel) to get your body prepared for the new time zone. The average person will naturally adjust one time zone per day, so if you’re an athlete traveling for a race, plan ahead! This might be one scenario in which a very low dose of supplemental melatonin is useful, which can help re-adjust the circadian clock to the new time zone [79]. A safe starting place is 0.3-1.5 mg 90-120 minutes before bed.

Go camping

Going camping is another great (and fun) way to reset the circadian clock [80]. The power of exposure to only natural light highlights just how important blue light (or lack thereof) is to establishing a healthy circadian rhythm.

Make your bedroom environment conducive to sleep  

Sleeping in a room that is too warm or too cold can ruin what would have been an otherwise restful night’s sleep. Optimal sleeping temperatures are between 62 and 66 degrees Fahrenheit (or about 17 - 19 degrees Celsius) [81]. Keep your room as dark as possible using blackout curtains and/or a sleep mask. If traveling, carry some dark tape to block the annoying bright lights emitted from electronics around the room. Earplugs or white noise may also help sleep quality, depending on your personal preferences.

Avoid sleeping pills

If you’re following the recommendations presented here, there is no reason you should have to resort to pharmaceutical sleep aids. If they are currently a crutch in your life, do everything you can to find healthier ways to promote restful shuteye [82].

Consider supplements

While not ideal to rely on in the long-term, some people may benefit from acute and targeted supplementation to get their sleep back on track. Magnesium [83,84] has been shown to be helpful for age-related insomnia and may also help due to its anti-anxiolytic effects [85]. Other supplements that may be beneficial include: 5-HTP, L-theanine, L-carnitine (if deficient), glycine or collagen hydrolysate, melatonin microdose, and Dr. Kirk Parsley’s Sleep Remedy.

Stick to a schedule

It’s important to minimize day to day variability in sleep timing [86]. Even on weekends, try to stick to the same bedtime and wake time plus or minus about 30 minutes. If you sleep poorly one night, go to bed at your usual time the following night. A few nights of catch-up sleep might help when life gets chaotic [87], but generally sticking to a schedule will be optimal for your physiology.

Practice gratitude and believe in your higher purpose

Most people have experienced worry or anxiety trigger insomnia. Implementing a gratitude practice can benefit just about everyone, but may be particularly useful for those struggling to get restful sleep [88,89]. Additionally, having a higher level of meaning and purpose in life is associated with better sleep quality [90].

Consider your chronotype and adjust accordingly

Just as it’s important to personalize medicine, it’s also important to personalize circadian rhythm. Some people will naturally wake up early and go to sleep early (larks) while others will naturally wake up late and go to sleep late (owls), but the majority of the population will fall somewhere between the two extremes. If your inherent chronotype suggests you might fall into one of the extreme categories, experiment and adjust the above recommendations to find what works for you. But make sure this is actually true to your disposition rather than a discrepancy between your social and biological clock!

Hopefully, by now you’re convinced that proper sleep and circadian rhythm entrainment are critical to health, performance, and longevity. But as a parent, athlete, student, or entrepreneur living in a busy modern world, you might still have an objection or two lingering in the back of your mind...

Objection 1: I have to get up early to train

Sacrificing sleep, even if it’s just an hour, for training is not a smart idea. While your individual chronotype may impact athletic performance [91] and busy schedules sometimes necessitate early morning workouts, training at the expense of sleep will almost certainly have detrimental effects on your performance and health in the long run. If you’re one of those people who need to do their fasted early morning workout, plan ahead and get to sleep earlier. Additionally, if building muscle is your goal, it might even behoove you to train later (but not too late, as discussed above) to elicit a greater anabolic signal [92].

Objection (question) 2: How do I know exactly how much sleep I really need?

Most adults require 7-9 hours of sleep [93]. If you’re an athlete or someone recovering from a chronic health condition, you’ll probably be on the higher end of that range. And if you’ve been sleep deprived for a while, you might find yourself requiring more sleep at first and less when you have paid off your sleep debt. Some simple math will help you determine how much sleep you personally require.

Let’s assume the average person needs 8 hours of sleep.