[Rhonda]: The other thing that is sort of
on this whole fasting versus TRE topic that
gets asked a lot that I have to ask you has
to do with coffee.
Actually, specifically caffeine, like black
coffee.
So without any cream or any calories or anything
like that.
So caffeine can start things, like the clocks
in your liver?
[Satchin]: Yeah, it resets the clock.
Because the clock is always running, it just
resets.
[Rhonda]: It resets it, okay.
So a lot of people in the intermittent fasting
community, they do a lot of fasting, whether,
you know, they're fasting for 16, 24 hours,
48 hours, but they drink caffeine and they
notice that they lose weight.
And so they say, "Well, I'm still getting
results."
[Satchin]: Yeah.
[Rhonda]: You know, "So it's fine, I can drink
my black coffee."
[Satchin]: Yeah.
[Rhonda]: You know, obviously someone that's
fasting for 48 hours, it's very different
than doing the TRE schedule where you're eating
for 10 hours a day or 11 hours a day, and
then fasting for, you know, 13 or 14 hours
every night, right?
[Satchin]: Yeah.
[Rhonda]: So if a person, for example, that
wakes up in the morning drinks black coffee
at 7:00 a.m.
They wake up, have some black coffee at 7:00
a.m.
But they don't eat anything, they don't eat
their first bite of food until...
[Satchin]: 10:00 or 11:00.
[Rhonda]: Yeah.
Yeah, something.
Then when do they have to stop eating by?
Like, is it when the coffee started or is
it when they ate the food?
[Satchin]: Yeah, so this is a question we
also get through the app a lot.
And we actually posted a blog on our website.
So here is a very different thing.
So since we look at circadian rhythm as a
whole, it has a sleep component, food component,
exercise or activity component.
And we know that caffeine resets the body
clock.
So, for example, drinking a cup of coffee
is similar to having exposure to bright light
for an hour or hour and a half.
So that's just on the circadian clock itself.
Now the question is, "Well, will it reset
that clock the same way if the coffee comes
in the morning versus evening or night?"
And we know that there is a term called phase
response curve.
So that means the same light, it relates to
light.
The same light will reset the clock differently
at different times of the day.
During daytime when your system is expecting
light, if you're in a dark room and we see
light it doesn't reset our clock.
But in nighttime it will reset our clock.
So we don't know what is the phase response
curve for coffee, whether it resets much more
at certain times and less at other times.
The direct impact of coffee on clock is unknown.
Then the second thing that relates to coffee
is sleep because coffee definitely suppresses
sleep in a lot of people, some people may
be resistant.
And the reason why we drink coffee is we wake
up, we get up from the bed, but we maybe are
still feeling sleepy.
We want to get that extra energy, that's why
we drink coffee.
And along that line, of course, drinking coffee
at night is a straight no-no because it will
have impact on sleep.
But in the morning we ask the other question,
"Are you drinking coffee because you did not
rest well, you did not rest enough?"
So maybe that's why you need coffee to reset
your mental clock, or brain clock, to start
it.
And sometimes it can be just a pure habit
or addiction.
For example, I used to like coffee in the
morning, and then I realized, "Well, let's
get rid of coffee.
What happens?"
Maybe for the first two or three days I got
a headache, and then now I'm used to drinking
just hot water.
It's just the feeling of sipping something
from a sippy cup.
It's almost like a baby sipping something
from a sippy cup.
And I realized that that's what I was addicted
to.
I can actually substitute coffee with hot
water and nothing changed.
I still felt energetic after my hot water
and I realized that that was my addiction.
[Rhonda]: After you got over the...
[Satchin]: After I got over the first two
days of headache.
[Rhonda]: ...withdraw.
[Satchin]: Yeah, withdraw symptoms.
And then it's always [Inaudible] the question
of metabolism.
When we drink coffee, is it going to trigger
metabolism or certain things in our gut so
that the gut will think, "Well, now I have
to start working, the rest is over"?
And we think that's where the metabolism or
the function of the gut to absorb, or digest
this coffee, send that caffeine to liver,
and then to brain does kick start right after
we drink coffee.
Because that's how we are feeling the effect
of coffee in the rest our body, because the
stomach started working, it absorbed coffee,
it sent it to liver, liver might have metabolized
it slightly and started to send it to the
rest of the brain and body.
And then it gets back to kidney, it gets metabolized
and excreted.
So then the question is, forget about circadian
clock, now if we think about just metabolism
and, say, mitochondria function, or even,
say, go back to autophagy, and then ask, "Is
caffeine breaking the fasting so that it stops
autophagy, or it stops something else?
Or is there a crosstalk between, say, caffeine
receptor and glucagon receptor so that it
does?"
No, fasting is kind of slightly over.
You may not be in 100% fast, but in 40% or
50% fast.
So that's where things become murky, so that's
why we say, "Well, if you can, drink your
coffee within this 8-hour, 10-hour, it's better."
But at the same time we know, going back to
the study that we discussed, Ruth Patterson
study, they did not consider coffee as food.
So when they considered 13 hours overnight
fasting, that 13 hours actually included coffee
and tea.
So in that we know for cancer, reducing breast
cancer risk, this 13 hours of fasting can
include coffee, black coffee, and tea.
So this is where things are really murky.
And we tend to error on the safe side, so
we tell, well, if you can have that coffee
within your eating window, that's much better.
If you can't, then just have black coffee.
At least that will not trigger your insulin
response or glucose response.
So that's what we do, we recommend.
