Original subtitles

So, there is a famous experiment that was published last year by Jota Kahasi's lab,

and it came out in Science.

And that relates to caloric restriction.

And we kind of started with this idea, we started discussion that the rat experiments

were done with caloric restriction, and researchers gave reduced calorie consumption by 20% or

30% and gave that food, the rats and then subsequently mice, and they all lived longer.

What is interesting is in all those experiments, the researchers came and gave this bolus of

food at one time, whereas the adlivetum fed mice or rats, they had access to food all

the time.

So, they were eating all the time, and then these rats were given 20% less.

And what happens is these mice or rats, they're not going to take that less food, which is

rest on now, and just eat a little bit of lunch and then snack after three hours or snack

after three hours.

They gobble up all that food.

Within two to three hours, maximum four hours, food is gone.

So, they're sort of on the OMAD diet, the one meal a day.

Yeah.

They're almost like one meal a day, three to four hours, food is gone.

Or you can say they're on four hours eating or feeding and 20 hours fasting.

So, then the question became, well, the benefit of calorie restriction, as we know, is it

due to reduced calorie or time restricted feeding or timing?

There is a timing component to it.

They're eating all of that within three to four hours, and then there is a long fasting.

And this is a difficult question to answer because now you have to ask these poor grad

students or technicians to come and split that food into eight or 10 or 15 different

small portions and then give them to mice in every two hours.

So, Joe Takahashi, who actually published the first paper in 2017 showing that most calorie

restrictions...

I mean, he used the protocol that was used by calorie restriction field.

It actually creates a condition of time restriction.

So he showed that and then he went back and worked with engineers to come up with a smart

case where he could actually tell, he could program how much food is given to mice at

what time of the day or night, completely programmed.

So then he took this...

For example, suppose the adlivetum fed mice eats five grams of chow in a day.

And if you want to reduce calories by 20%, then the CR mouse should get four grams of

food.

And he divided this into nine or 10 meals and then gave them in every 90 minutes.

So in this case, they're eating small meals throughout the night.

So there is no fasting.

So you can say that, well, this mouse actually is not getting into fasting because in every

few hours is getting some food.

And then he measured how long the mouse is going to live.

And he used...

This is a very standard protocol.

People count how many mice are dying on which day and then examine them to see whether they

died because there was an accident or there was a natural cause.

And then they calculate at the end, what is the half life?

So 50% survival, because on an average, that's a good indicator because if there is an outlier

that will live for a long time, then that can skew.

So what was interesting was the adlivetum fed mice, of course, they live certain number

of days.

And then this caloric restricted mice that never got into super fasting, but kind of

eating, snacking throughout the night, that also live 10% extra, 10% longer.

So that means caloric restriction extended lifespan by 10%.

I've wondered about this because recently there were a bunch of news headlines about

intermittent fasting.

And frankly, I was frustrated if you looked at one major news outlet, they would say,

time restricted feeding affords no additional benefit beyond caloric restriction for weight

loss.

Then another popular press venue, let's call it that, same study described as time restricted

feeding doesn't work.

And then another one, maybe someplace even more extreme, time restricted feeding only

beneficial because of caloric restriction or something like that.

So what you've essentially got are three different interpretations of the same data, all of which

are, well, two of which are true, one of which is false in my opinion.

But what I think people take away from that is, oh, time restricted feeding isn't valuable,

which is not the case.

I think for many people it's a convenient way to eat because at least for people like

me, it's simpler to designate between portions of my day when I'm eating and portions of

my day when I'm not eating as opposed to eat portion control.

For other people, portion control can work.

But all of that is related to either maintenance or loss of weight.

None of it deals with the potential health benefits independent of weight loss.

And so I think that if we can segment those out, obviously in humans it's hard to know

if a given treatment or experiment is extending life because you don't really know how long

people would live anyway.

Whereas with mice you have some sense of when the mortality was likely to occur.

So what can we say about time restricted feeding and longevity in terms of biomarkers or in

terms of any other indication that people who start and stop their feeding window at

a consistent time, somewhere between eight and 12 hours per 24 hour cycle, are tilting

the scales towards living longer as opposed to living shorter?

This example of this news article that you mentioned is really interesting because that

relates to Joe Takao's study because I described that if you split calories and eat throughout

the day, throughout day and night, then the mice live 10% extra.

But if you now give mouse the same calorie restricted diet and feed them during daytime,

whether within 12 hours or two hours, then the mice live 10% extra.

Beyond that.

Yes.

So 20% longer.

20%.

I don't know if I understand so that I make sure I understand.

If you take a certain number of calories and you distribute them throughout the 24 hour

cycle, it's caloric restriction, the mice will live 10% longer.

If you however restrict that to the active cycle, so for humans the daytime, then they

live 20% longer.

So it's not just total caloric intake.

Meaning it's not just important to be sub maintenance and calories for sake of longevity.

It also is important as to when in the 24 hour cycle you eat those calories.

Do I have that right?

So now that's still the story is not over because this mice are fed during daytime and

they're not supposed to eat.

That's right.

So for us, it would be the equivalent of being on the night shift and only eating at night,

but a subcaloric sub maintenance calorie diet, I guess is the right way to say it.

But when he fed mice during nighttime when they're supposed to eat and they're seeing

this, getting the same number of calories within 12 hours or two hours, then the mice

live 35% longer than they control.

35% longer.

So scale to human lifespan, which we don't know, but a 35% longer would mean that, and

again, no one knows, but humans now, what is the average mortality in the United States?

Somewhere around 80?

Yeah, so it's around 80, it used to be 80 now, reduced a little bit because of COVID,

but let's take 80.

Okay.

So people are then now living somewhere between 25 and 35 years longer.

I'm putting some arrow bars on there.

Yeah.

Amazing.

So that was really profound, but now you pointed out biomarker and other stuff.

So now if you look at any given time within that experiment, and actually Joe went back

and had a separate cohort of mice, very similar, and so that he could take tissue samples,

and of course, in this case, you have to sacrifice the mouse.

And he did a lot of molecular analysis with known markers.

For example, hemoglobin A1C equivalent or glucose control, cholesterol, all this stuff.

He could not find anything that predicted the benefit of caloric restriction.

So that means in this experiment, whatever we know so far, the predictor of longevity,

none of them could predict whether this CR only mouse, which ate throughout day and night,

that mouse is going to live less than the night fed mouse that was going to live 25%

extra.

Does that mean that there are biomarkers related to longevity that we just haven't discovered

yet?

Yeah.

So that's exactly.

Whatever we know so far about biomarkers, those he could not use to predict.

Maybe there was a lot of noise.

Maybe he had to use more number of mice to get that because biomarkers are not going to

predict in every instance that there is some error.

What is also very interesting is if you look at the body weight and body composition of

all these mice, there is no difference in body weight and body composition.

Across all these different groups.

All these groups.

So it doesn't matter when they ate, provided they were sub-maintenance calorie intake.

So fewer calories than is required to maintain their weight.

It didn't matter what pattern of eating, they were the same weight.

So that in many ways seems to mimic the human studies where they say, look, it doesn't really

matter whether or not you use caloric restriction or you start your feeding window in the morning

or start your feeding window in the evening or you portion control for sake of weight

loss.

Because you're taking a snap sort of that.

And then another thing with the human study that we are referring to here, in that human

study, people are actually already eating within 10 hours window.

Habitually, when they selected these people to have them enroll in the study.

So they were already eating for 10 hours and fasting for 14 hours.

All participants had to reduce their calorie intake and they reduced by almost 25%.

The CR group continued with 10 hours eating window and the CR plus time restricted group

had to eat the same number of calories within eight hours.

So it's just a two hour difference.

It's just a two hours difference.

Okay.

So that people, I just want to make sure people can understand.

So in this human study, which is the one that I felt that the popular press venues, all

except one venue, got either semi wrong or badly wrong in terms of their conclusion.

That was my interpretation anyway, was that either people came into the study eating basically

in a 10 hour feeding window, which goes back to my first question, which is that most people

are not eating in the middle of the night.

Yeah.

Or if they're on shift work and they are, then they're sleeping during the day anyway.

So they're eating in a 10 to 12 hour feeding window anyway.

So you're saying they either did caloric restriction portion control within a 10 hour window or

another group within the study, eight sub maintenance calories to caloric restriction

CR, as we're calling it, the acronym CR, but restricted to that to an eight hour feeding

window and they didn't see any difference in terms of weight loss.

Yeah.

But it's not all that surprising, right?

I mean, if it's just a two hour difference.

Yeah, exactly.

So we have done that experiment in mice and we don't see difference in not only weight

loss, many other markers.

And I was telling you about this Jota Kahasi's paper where I told you that he allowed these

mice to eat within two hours or 12 hours, subcaloric diet.

Two or 12.

Two or 12.

Yeah, that's dramatic.

But still, he did not see change in longevity even within those two.

So that means when you do caloric restriction and then at least for months and you are within

12 hours window, that is giving the mice the best benefit, the optimum benefit.

And two, three or five or 12 per mouse doesn't matter, at least for longevity.

Can we conclude for humans that whether or not a feeding window is four hours, six hours,

eight hours or 12 doesn't matter provided the calories are similar or same?

Well, I won't go to that extent because we don't know many of these, particularly we

don't know how this sort of eating window will affect both sexes because we always think

many of these mouse experiments, even that I told you about, those are done only in male

mice.

But that should be changing, right?

Because the NIH, I know this because I'm on study section, which is just a bunch of people

who review grants, is that every grant now has to include sex as a biological variable.

It's hard to get away with, or rather I should say it the way it should be stated, which

is people are required and should want to look at these phenomenon in male and female

mice, especially if there are differences.

So in this case, there are many, I mean, there was also another paper in Time Restricted

Feeding that also came out, a big paper showing that the thermogenesis was accounting for

loss in fat mass in time-restricted fat mice.

That was also done only in male mice.

So this is, we are paying attention to it.

So we are now doing all of our studies in male and female, and we do see big differences

between male and female.

Coming back to humans, what typically happens is when you're trying to do four hours or

six hours of time-restricted eating, people will inadvertently reduce their calorie intake.

Just because of gut volume.

I tried one meal per day, and I felt like I was eating so much at that one sitting that

it led to a lot of gastric distress, and I got tired after the meal.

And part of the reason I like to do time-restricted feeding is I have more energy.

And certainly in the fasted state, I feel more energized, especially if I'm ingesting

a little caffeine or something like that.

So people will reduce energy intake, and then some people who are more active, they can

actually, unconsciously, they may be spending more energy in their physical activity and

basal metabolic rate, all of this combined than how much they're eating.

And that can have a very adverse effect in long-term because we know that this energy

deficit, and in fact, there is a scientific term for that.

It's called RAD-S, relative energy deficit in sports.

Relative energy deficit in sports.

Okay.

Yeah.

40% of athletes, not the NFL guys, but there are a lot of people who do track and field,

and nearly 40% of athletes actually experience this RAD-S without knowing.

Can male and female athletes both experience RAD-S?

So it's RAD-S, relative energy deficit in sports.

Interesting.

This is the first I've heard this acronym.

We have a new acronym, folks.

This is good to add to a list of other acronyms.

So males and females can experience it.

So in females, I've heard that RADs can lead to eminorrhea, so loss of the menstrual cycle.

Yeah.

So that's so common, so prevalent that in fact, many women, many female athletes, they

take it for granted that, yes, if they are more active, then they will lose their menstrual

cycle, which may be common, but it's not normal or optimum for health.

Even if they don't want to get pregnant.

Yeah.

Yeah.

Yeah.

We had an expert on female hormones come on and say the very same thing, that regular

cycling is a...

It's very important.

... of ovulatory menstrual cycle is important to try and maintain.

Yeah.

So that's one.

But then what is really concerning is it does affect bone health.

And in this state, people actually over a long period of time, they lose bone mass and

their bone also becomes more prone to injury, micro fracture and fractures.

So again, it's a risk.

I mean, some people are trying to eat within very short time and they're physically active,

that happens.

And it also has impact on...means the reason why these women are losing menstrual cycle

is the HPG axis is disrupted, hypothalamus, pituitary, gonadal axis.

And it starts in...may start even upstream at hypothalamus or pituitary.

So that means that HPA axis, hypothalamus, pituitary and adrenal axis may also get disrupted.

One of the symptoms of reds is also depression, anxiety, bipolar-like symptoms.

And we know that many, many athletes experience that.

We think that, well, this may be just peer pressure that always trying to compete.

And we know that unfortunately there are a few athletes who just can't cope it and there

are many attempted suicide or suicide.

So this is a serious issue.

And there's also another new topic in the lab to come up with a mouse model of reds

and then study it.

But this is one risk why we should not reduce our eating interval to one meal or very short

time, because it can have adverse side effect that we don't know now.

Maybe in future we'll figure out when we systematically study them.

There are studies that are published showing four hours and six hours time restricted eating

has benefits on weight loss, but those are on healthy individuals and they were in the

studies.

So the study team were already monitoring, they made sure that there was no sudden weight

loss or weight loss below some safety level.

So those are very different from regular people who are maybe even normal weight, even with

within the healthy range.

If they do, then they can potentially.

So that's why what we think is eight to 10 hours may be the ideal spot to begin with.

And once you are physically active and you are also spending a lot of energy in physical

activity or sports, you can even go up to 12 hours because in mice we have done that

experiment up to 12 hours, they do get a lot of benefits, not all but...

So this is 12 hours of...

12 hours of eating, 12 hours of fasting.

In humans, again, nobody has done systematically 12 hours, but there was one study in Europe

from Tin Hai Collette Lab and Tin Hai and I, we collaborate.

So they used our Mycica Indian Clock app.

This is a research app we developed just to...

This is mostly used in time restricted eating studies.

And he had nearly...I think he started with 200 Swiss participants, but then at the end

he selected and took very small number of groups.

People who are very meticulous about recording all their food and divided them into usual

feeling whatever they wanted to eat, whenever they wanted to eat.

And they were given the advice of Swiss nutrition advice that's given to improve health and

reduce blood glucose, almost like diabetes prevention program in the US.

And then the other group was given advice to eat within 12 hours.

This is very early on in time restricted eating and we thought that the mice were getting

some benefit, let's try whether 12 hours has any benefit.

The bottom line is at the end of three months and six months, what he reported is both groups

lost same amount of body weight.

And then there's not too much significant difference between groups, but both groups

actually improved their health.

So the bottom line is the Swiss nutritional advice that he was giving, which is the standard

of care there, it achieved the same amount of weight loss as just giving people this

advice that eat within 12 hours.

So one way to look at it, look at the result is like this.

And then he went to more extent and actually looked at every single meal these people consume.

So there are close to, I think close to 60 or 70,000 meal records and pictures he went

through and then classified them to say whether these are good quality food.

So they call it the NOVA classification, one, two, three, four.

One is the food that you can almost eat raw fruits, vegetables, yogurt, dairy products

that you can almost without any preparation.

And then second, NOVA two is kind of home-cooked food that most people will prepare in a few

minutes and then three.

And then fourth one is the food that you can never prepare at home.

So for example, biscuit or cookies that we usually purchase and a few other things.

And usually the NOVA four are unhealthy ultra-processed foods, so which we should not be eating.

So the advice is to reduce NOVA four.

And what he found was people who got all this advice to improve their nutrition quality,

they actually improve their nutrition quality.

They reduce their NOVA four food.

And people who are in time-restricted eating, they ate within 12 hours, they did not change

their nutrition quality.

But what is interesting is they both got the same modest weight loss.

So that begs the question that maybe Chinhai will do this experiment again to combine nutrition

advice with time restriction and maybe reduce the time to 10 hours and that might help.

So 12 hours is something that I say anyone from five-year-old to 100-year-old can do.

And if you are trying to maintain weight, that might be a good way and combine that

with exercise, it'll be great.

And people can more easily avoid reds in that way.

Women and for non-athletes or recreational exercises, it sounds like women, if they distribute

their calories across 12 hours are less likely to lose their menstrual cycle.

Yeah.

So again, this is something that we have to look carefully.

Because we do have the Mycetidine Clock app that many people download and self-monitor

and they share the data for researchers.

We will provide a link to that, by the way.

It's a great tool.

Yeah.

But once in a while, we do get this input from some women saying, oh, I started doing

your time-

ratio eating and I am seeing all these problems.

And then I asked them, okay, so what else are you doing?

They typically improve their nutrition quality.

So they're eating only salad and few and they're trying to increase their fiber intake.

And it's really hard to eat so much of uncooked food because cooking helps to absorb more

nutrients.

And then at the same time, they're running five miles every day.

And of course, all of this combinedly can lead to red-like symptoms.

So that's why 12, I think, is a good point if you're combining physical exercise and better

nutrition quality.

Because in mice also, we have seen that if mice are eating healthy food and they're eating

within 10 to 12 hours, then they also live longer than mice that are eating healthy food,

but distributing that calorie over a long period of time.

And this is Rafa Di Cabo's finding from NIH.

He has systematically done this study with two different types of diet and in mice.

And he finds the same thing, that even mice that are eating within 12 hours, they do live

longer than mice that eat randomly even healthy food.

I recall a recent study, I think it was either published in Cell Reports or Cell Reports Medicine.

Forgive me for not remembering which, but both of course, Cell Press journals, excellent

journals, which explored time-restricted feeding in the context of low carbohydrate

or non-low carbohydrate diet.

So it was low carbohydrate versus low carbohydrate and time-restricted.

So these are all caloric matched between groups.

And then non-low carbohydrate diet.

So it's a more standard, I think it was somewhere in the neighborhood of 60% of calories from

complex carbohydrates.

And as I recall, the greatest weight loss, remember, same calories across groups, folks,

was achieved with low carbohydrate plus caloric restriction.

And I wondered why all the popular news venues didn't cover that study, but that's why I'm

bringing it up now.

I thought this is really interesting.

And I'm somebody who's cycled low carbohydrate diet before.

I find it hard to sleep after about three or four days of being on a low starch diet

just personally.

So I like to eat some starches, especially if exercising intensely or working intensely.

That's just a little editorial there.

But look, I know many people who do just feel better on a low carbohydrate diet.

But what do you think of those data?

Because it speaks to the idea that, okay, it's not just the total number of calories.

It's not just the quality of those calories.

Perhaps the timing of those calories and maybe carbohydrate restriction in conjunction with

time-restricted feeding might be the best path for people who are looking to lose weight.

No, I totally agree that when it comes to nutrition, quality, quantity, and timing,

all these three matter.

Nearly 40% of people who maintain healthy body weight, because 60% are overweight and

obese, 40% are maintaining healthy body weight.

And out of those 40%, I would say nearly majority of them are very aware about how much they

are eating and what quality of food they are eating.

So you're really an optimist.

You're looking at the 40% of the glass that's, or should we say not full?

That was a pun intended.

But no, that's a very interesting way of looking at it.

Rather than saying, why are 60% of Americans obese, saying, why are 40% not obese?

That's a very interesting way to look at it.

I mean, subconsciously, we're always making that decision.

I mean, I'm sure that you are not going and eating cheeseburger every day because you

want to improve.

Yeah, exactly.

I wouldn't feel good.

I enjoy cheeseburger now and again, but no, certainly not at this stage or any stage of

my life.

I think people, actually, you think the pandemic had a lot to do with this.

I think that people started to take a look at what they were doing to support or not

support their health generally.

I know people gained a lot of weight during the pandemic.

Other people got really into fitness.

I've seen some colleagues, you've always maintained, you've always been in good shape.

Actually, this first time I've seen you in a while, you seem to have aged backwards.

So you are a poster for your own ideas and hypotheses about time restricted feeding.

But I noticed that during the pandemic, a number of people emerged from the pandemic

in better shape.

Other people in much worse shape.

It seemed like it was like a bimodal distribution there.

So yeah, I get the sense that starting and stopping eating at more or less the same time

each day, even if caloric restriction is not the main focus, has additional benefits.

And we talk about some of those benefits as they relate to the other things that impact

health.

So for instance, if you're starting and stopping eating at more or less the same times each

day, are you sleeping better?

Are you getting more predictable shifts in alertness and sleepiness?

Can you predict when you'll feel good enough to exercise?

Maybe we could talk about that because you, of course, are well known for time restricted

feeding and the science around that, but also other things as well, not the least of which

is circadian biology generally.

So I always think of the main timekeepers for our system being feeding, light, activity,

and social connection.

Did I miss?

And temperature.

Yeah.

Yeah.

So how do these combine with one another and using timing that we begin and stop feeding

as kind of an anchor point?

Can we explore that a little bit?

Yeah.

So we got into this beginning and end and then you asked for the calorie, how much calorie

will break the fast?

One thing that I want the listeners and viewers to bring back to this timing of when we're

breaking the fast because we equate health with weight, body weight.

And that's when we are talking about nutrition quality and quantity because both of them

have impact.

So now let's think about mental health because a lot of people do struggle with mental health.

They have anxiety or depression and also so gut health because there are a lot of people

who also have acid reflux or heartburn.

And we know that acid reflux or heartburn can be exacerbated by caffeine intake and

empty stomach.

Those who have acid reflux or heartburn, they're prone to that.

Then having black coffee in the morning before any food can upset their stomach.

So that's why in those cases, it's very clearly that caffeine for them becomes the trigger

that something, the food is supposed to come and then the stomach is not seeing the food.

So it's overreacting, producing excess acid and that comes up to the esophagus and that's

where they're experiencing.

So if people have that kind of condition, then maybe they should consider when they

drink their first coffee is breaking their overall fast or kind of putting their health

at risk for acid reflux.

The other thing is people who have anxiety, panic attack, we know that caffeine can judge

you off.

Especially on an empty stomach.

Especially on an empty stomach.

So for them, again, caffeine can be a trigger.

So that's why I want to kind of differentiate that there is this mental health and other

aspects of health.

And these are two clear examples where anxiety, panic attack, related to brain health or acid

reflux related to our gut health.

In those cases, when we consume that caffeine in the morning can affect.

And do you avoid caffeine in the morning?

No, actually, here is the interesting history about caffeine.

And this is something I did not know.

And I was once invited to this history of nighttime activity.

And maybe we can take a little bit of detour and talk about nighttime activity because

that fascinates me as a circadian biologist.

Because over the last 200,000 years, we assume that humans, homo sapiens evolved 200,000

years ago.

So we have been, as a species, we have been living on this planet for 200,000 years.

And only in the last, you can say, couple of thousand or 5,000 years when we came to

control fire, or maybe you can even go back to 100,000 years, that is some debate.

So then the question is, well, when you control fire and we lighted up the fire, and we could

light up whenever we wanted, we can add fuel and we can stop the fire when we don't want

it.

That's the key ability in humans that differentiates them from all the other species.

No other species.

We can always say, yes, there are signs of this intelligent decision making.

For example, we know many crows can make decisions, many animals, they kind of figure out, strategize

how to get food.

But controlled use of fire is something very specific to human.

And when we started controlling fire, fire did not essentially extend the day because

fire created an evening that was very different from what people did during the day.

And what people used to do during the day, they worked a lot, means gathering food was

almost everything that we did.

And so in the evening after we brought food, mostly tubers or maybe lentils to cook or

once in a while animals so that we could barbecue, all of these things happened around fire.

And fire was so expensive that it was mostly communal fire.

So if you go back to, for example, Maasai and all these populations that have no access

to electricity and are still living kind of that historical life, fire is a communal event.

And they sat around, they cooked food.

And then what happened?

They did not talk about work.

They talked about culture.

They sang, they danced, they strategize.

That's how politics started, philosophy started, science started, all of these things that

are very unique to human civilization started around fireside chat.

So in that way, if you think about it, we are still doing fireside chat.

The only thing is we have the microwave and the television, our social media.

And now we chat with our phones.

So we are hooked to that evening activity because that's when we are completely free

from the pressure of the work and we want to express ourselves.

That's our independent time.

So that's why most people find it very difficult to do time-restricted eating and stop eating

at six o'clock because it's ingrained in our even DNA that we want to eat and socialize

in the evening.

So now let's fast forward and see what is the role of coffee in this.

If you look at coffee concoctions, particularly cafe, where people can come and have a little

bit of coffee and socialize, it also started as an evening activity.

And now we can go back to Istanbul because that's one place where cafes started in mid-16th

century.

So we are talking about 1540 to 1570.

And that's when...

I'm sorry, I'm forgetting the name of historians who actually invited me.

Okay, his name is Cemal Kefadar.

And I must be butchering the name, but I'll try...

We will provide the spelling.

And the wonderful thing about social media is somebody will tell us on YouTube the proper

pronunciation.

So this is a great opportunity.

If you know the proper pronunciation, please put it in the comments on YouTube.

Actually, I'm even checking right now in my EndNote library.

It's not picking up that.

That's right.

We'll provide a link.

So what happened was coffee was introduced and people came and drank coffee and talked

about politics.

At night.

At night, at evening.

And it actually started with Sufi branch of Islam because they are the ones who consume

coffee in the evening.

And this is the branch of Islam where they actually sing and dance and all that happened

in the evening.

So singing and dancing by the Sufis.

And then here in Istanbul, people started congregating and having talk about politics.

But then around the same time, in Turkey, there was a good sizeable number of Muslims

who have to do five prayers a day.

Number of prayers at set time.

The first prayer is very early in the morning.

And then they figured out that if they wake up and immediately have coffee, then they

can stay awake for the first prayer.

And in that way, they felt pretty good.

They woke up.

So that's how it started as a morning drink to stay awake and kind of get on with the

day.

But what happened was, I don't know whether you have ever tried Turkish coffee.

It's very thick.

Yeah.

A few years ago, right before the pandemic, 2019, I traveled to Turkey.

First of all, the food is amazing.

The coffee is indeed very, very thick.

Yeah.

And I have a pretty high caffeine tolerance from drinking so much coffee and yerba mate

over the years and still do.

I really enjoy it.

But yeah, it's very intense.

So what you're saying is that coffee intake started as a way to extend into the night.

The ability to extend into the night at all was because of the ability to harness fire.

And then coffee's stimulatory properties were leveraged toward morning, which is essentially

like the way I think about it.

We did an episode on caffeine and someone else, Michael Pollan, not I, described it

this way, that you're sort of taking a loan out on your energy bank account with coffee.

You're suppressing the adenosine system.

Adenosine makes you sleepy.

But that adenosine system will kick in later.

So it's a credit card of sorts with an interest rate.

And the interest being an energetic lag that you're going to experience in the afternoon.

Yeah.

But what happened was the strong coffee, that gave heartburn and acid reflux to a lot of

people.

So then they started eating something with coffee.

And that's how the culture of breakfast started in Turkey.

So coffee actually led to the development of breakfast, not the other way around.

And that, yeah.

That's very heartening.

Again, no pun intended for the caffeine lovers among us, which I count myself one of those.

So essentially the food before coffee became breakfast.

So you kind of give something to your stomach so it's busy digesting that.

And then when the coffee comes in, it's not reacting to coffee and creating acid reflux.

So it wasn't as fascinating.

So it wasn't that breakfast is necessary on its own.

It was essentially a buffer against the gastric distress caused by caffeine intake.

At least in that culture, in that context.

We cannot say that whether the same thing happened in all over the world where coffee

is not consumed, but still people eat something in the morning.

You said you start your first meal of the day at around eight.

What time do you wake up?

I wake up around six.

I started at six.

What time do you have your first caffeine?

No, actually I have...

So that's why I brought up this story because I have coffee after my breakfast.

Fantastic.

I'm a big proponent of delaying caffeine intake for a few hours after waking for other reasons

that my listeners have heard me talk about endlessly, so I won't bother with that now.

But I think just suffice to say that allowing some of the natural waking up signals to occur

and using light to kind of clear away and adenosine to further extend and activity is

better than using a stimulant, but until a few hours later.

This is fascinating because I've never thought about the link between extension into the

night socialization or socializing rather, feeding and caffeine.