Low Sleep and Circadian Rhythm Misalignment: The Fourth Big Reason Why You Are Fatter Than a Hunter Gatherer (Nutrition For Health and Hypertrophy Part 22)

In the previous part of this series, we talked about the second big reason for the question posed in part 17:

If it’s not carbs, not sugar, not fats, not red meat, not plants, not animals, why are we dying from diabetes, hypertension, and heart attacks and hunter gatherers aren’t? What are we doing wrong?

The first part of the answer was that the food we eat is highly palatable, far more than anything our hunter gatherer ancestors ever had access to.

The second part of the answer is that the food we eat is cheap and convenient. It requires very little effort for us to acquire, prepare, and consume it. No hunter gatherer ever had such ease and convenience.

The third part of the answer is that people in industrialized societies have high levels of chronic stress, which increases cravings and appetite for highly palatable comfort foods. Hunter gatherers have lower chronic stress levels, and do not have access to modern comfort foods.

In this part, I’m going to give you the fourth big reason why humans in industrialized societies are fatter than their hunter gatherer counterparts: Sleep habits.

Sleep

Sleep does a whole bunch of things for you, and one of the things it does is that it allows the brain to clear out waste products that accumulate during your waking hours. It also helps form long term memories (i.e. your brain remodels itself during sleep time).

As such, sleep is really important to the nervous system, and every animal that has a nervous system has a sleep-wake cycle. Even the ones that split off from our evolutionary chain a long time ago (e.g. invertebrates like snails).

Sleep and Appetite

When you do not sleep well, your appetite goes up. You feel hungrier and end up eating more.

There are many studies that demonstrate this. Even sleeping 1-2 hours less than normal increases calorie consumption by hundreds of calories.

It seems to be very similar to the effect of stress (covered in part 21) where the appetite for highly palatable foods goes up. You are more likely to crave pastas, pizzas, garlic breads, cake, etc. when you are sleep deprived.

It’s possibly coming from your body thinking you are “tired”, which it’s interpreting as “I need more energy”, and thus increasing your hunger levels. Although more research is needed to figure out the exact mechanism and I’m just speculating here.

The end result is that you end up eating more calories, and thus end up getting fatter.

Circadian Rhythm

It doesn’t just seem to be sleep deprivation that causes an increase in appetite, but also messed up circadian rhythms.

People who do rotating shift work (they don’t have a fixed work schedule and have changing working hours) have poorer health in all aspects. They are more likely to be obese, have type 2 diabetes, cancer, heart disease, etc.

Not having a set circadian rhythm seems to be very damaging to the body. The longer people live like this, the worse their health gets.

The great question that arises is: Does your sleep cycle have to match the natural sleep cycle that hunter gatherers have (rising with the sun, and becoming sleepy around sunset), or can you sleep in any 8 hour slot as long as you are consistent.

Is waking up at 12 pm and sleeping at 4 am (i.e. the 8 hour sleep pattern often seen in the modern industrialized world) the same as sleeping at 10 pm and waking up at 6 am with the sun (i.e. sleep pattern you’d have in a hunter gatherer environment)?

There’s not a lot of good research into this topic, but from the data we do have, it does seem to worsen markers of insulin resistance and inflammation.

In my opinion, it does make a difference. If you wake up with the sun and sleep on time, you will have fewer cravings than if you get the same amount of sleep but wake up much later during the day (and thus spend more time awake during the late night hours).

But that’s just my opinion, and not “proof” of anything. Future research could prove me right or wrong.

I used to work in one of the big consulting firms when I was a late teenager, and often we’d work late into the night till about 2 AM.

And me and most people in the team gained weight because we’d all order junk food in the late night hours (it was paid for by the firm) and party on it.

There’s something about being awake late at night and wanting to eat junk food. Whether this is cultural/environmental, or genetic, or both, needs more research to conclude.

It is also possible that sleeping during the day and being awake during the night somehow reduces TDEE for that day, and thus creates a caloric surplus. Again more research is needed on this topic.

Sleep and IQ

This is something not related to nutrition, but is important enough that it deserves to be mentioned: Sleep restriction makes you dumber.

It makes you underperform on all cognitive tasks. The more sleep deprived you are, the worse your performance.

More importantly, the subjects in these studies stop realizing that they are sleepy after a few days. They only feel sleepy initially, but then they become “used to it”.

Their cognitive performance stays impaired, but they just stop being aware of it.

There are tons of people today who operate every day with a cognitively impaired sleep deprived brain, but simply have gotten used to it and are not aware of it.

Sleep is just so important.

If you are not sleeping enough, you are worsening every aspect of your body. You become dumber, less alert, fatter, more likely to get diseases/disorders like diabetes, heart disease, and cancer, etc.

Practical Recommendations

1) Sleep enough hours

Other than losing excess fat, getting enough sleep time and quality is probably the highest ROI thing you can do for your health.

Get 8ish hours of sleep or whatever you naturally need. It WILL improve your cognitive performance, memory, and a whole bunch of other physiological things.

You have to make sleep a priority. It is more important than texting girls from dating apps, more important than any TV show you can watch, and far more important than masturbating to internet pornography.

2) Wake up with the sun and have a fixed circadian rhythm

We have evolved to live in sync with the day and night cycle of the planet.

When your eyes receive sunlight (full spectrum light), it causes the release of hormones that promote wakefulness and the suppression of hormones that promote sleepiness.

Try to wake up at the time the sun rises in your location, or as close to it as possible. You will adjust to the new schedule in a few weeks.

Waking up late and thus staying up late at night promotes the consumption of highly palatable comfort foods simply because people do not seem to be able to make good food choices late into the night (whether it is culture, or genetics, or something else, is up for future research to determine).

3) Avoid artificial light late at night and sleep in a dark room

The opposite of #2 is also true.

When your eyes are in the dark (night time), it causes the release of hormones that promote sleepiness (like melatonin) and suppresses hormones that promote wakefulness.

Research has determined that it is primarily the blue portion of the light (highest from the sun during mid-day) that influences the body’s sleep and wake cycle.

When you subject yourself to artificial light containing blue wavelengths from TV screens, phones, computers, LEDs, etc. you essentially trick your body into thinking that the sun is still up, and thus cause the suppression of sleep promoting hormones like melatonin.

What I recommend is to turn your screens off (or at least reduce brightness significantly) after the sun has set.

If you have strong overhead LED lights in your house, keep as few of them on as you need. Don’t light up your bedroom so much that 8 PM feels like the sun is up.

If you must use screens, consider using apps like F.lux which in all fairness, I just find too annoying. I typically just reduce overall screen brightness.

You can also experiment with blue light blocking glasses. However, the evidence on how well they work is mixed. I had LASIK all the way back in 2018, but before I got the surgery, I used to wear blue light blocking glasses I got from Lenskart. I used them for a few years.

I do remember feeling sleepy earlier than I did before them. It’s worth trying out to see if it makes a difference for you.

Sleep in a dark room so city lights seeping in do not worsen your sleep quality. Consider using a sleep mask or invest in light blocking curtains.

4) Get treated for problems that could be ruining your sleep quality like sleep apnea

Finally, there are some people who go their entire life living on shitty sleep because of undiagnosed conditions like sleep apnea.

If you suspect you have any medical problem that could be causing poor sleep, get yourself tested and do whatever you can to fix it.

Your good health depends on how well you sleep, and fixing the bottlenecks preventing you from sleeping well is well worth the time and investment.

That’s all for this piece.

In the next piece, we’ll talk about the theory of settling point because it naturally flows from everything we’ve discussed so far.

– Harsh Strongman