September 16, 2025 • 23 mins
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Speaker 1 (00:09):
Hey, everyone, Welcome to another edition of Wisdom Wednesdays. And
just before we start, another shameless plug for my book,
The Hardiness Effect, How to Grow From Stress, Optimize your
health and Live Longer, is now on pre sel with
a twenty six percent discount on Amazon, so jump amongst
it and get involved. I am also shortly going to
(00:32):
be announcing a hardiness intervention to coincide with my shift
towards All Things Hardiness, where I'm actually going to do
my first ever public workshop. But I'm going to combine
that public workshop with a six week program in the app,
My Hardiness App, which is very closely mirrored to the
(00:54):
research study I did in my PhD where we took
a bunch of busy corporate did a day's hardiness training
with them.
Speaker 2 (01:03):
They had eight weeks on the app.
Speaker 1 (01:04):
We measured their cognitive function, their cognitive performance, their hardiness,
their mood, their gratitude, their stress, and their resilience and
had statistically significant improvements in almost everything. And I am
now going to bring this to the general public, so
standby for an announcement. There will be a one day
workshop in Melbourne, probably at the end of October start
(01:28):
of November, but what's this space?
Speaker 2 (01:31):
So now on with the podcast.
Speaker 1 (01:33):
So today we're going to go deep into one of
the oldest practices knowing to humankind, and that is fasting.
As you probably were, it's been used across cultures for religious, spiritual,
and therapeutic purposes for thousands of years, and in recent years,
intermittent fasting and time restricted eating have taken the health
(01:56):
world by storm.
Speaker 2 (01:58):
But today we're not going to talk about.
Speaker 1 (02:00):
Skipping breakfast or doing sixteen eight or any of those things.
We're talking about a prolonged water fast only and specifically
going to look at the effects of a seven day
fast and what it does to the human body right
down to the level of thousands of proteins circulating in
(02:20):
your blood. And we're going to explore a groundbreak and
study that was just published in Nature Metabolism, and also
some other commentary that was published again in the journal Nature,
really looking at the comparison of shorter fast the three
or four day waterfast that many of you have tried,
(02:40):
with some longer fasting. And by the end of this episode,
I hope you'll have a pretty nuanced understanding of the benefits,
the risk, and the biological effects of extended fasting, and
a bit of clarity about were, if any were it
might fit in your own health journey.
Speaker 2 (02:58):
So let's start with the research.
Speaker 1 (03:00):
A team of scientists from Berlin, Cambridge, Copenhagen and Oslo
recruited twelve healthy young volunteers. Five of them were women
and seven were men, and this is important because it
was both sexes.
Speaker 2 (03:14):
And they asked them.
Speaker 1 (03:15):
To do something simple but definitely challenging for anybody who's
ever done it. Drink only water for seven days straight,
no calories whatsoever. And throughout the week, the researchers collected
blood samples every morning and use the cutting edge proteumic
platform to measure nearly three thousand proteins circulating in their plasma. Now,
(03:40):
anybody who's heard me talk about the twelve major hallmarks
of aging, one of those major hallmarks is loss of proteostasis.
So basically, changes in how these proteins that circulate in
our blood changes in them and how those changes actually
accelerate to aging. And proteins are really the building blocks
(04:03):
of all life. So in this study, they also tracked
their body weight, their fat mass, their lean mass, their
hormones and then metabolites like ketone bodies and fatty acids.
So let's talk about what happened. So, as I said,
twelve participants, five women and seven men, and they measured
(04:24):
them before, during, and after a prolonged seven day fast
with absolute calorie restriction, and they can just drink as
much water as they wanted. So they took fasting blood
early in the morning between six and nine am from
all participants two days prior to the intervention. Then they
took it daily during the intervention and then again three
(04:47):
days after stopping the intervention, and in their plasma they
looked at a total of twenty nine and twenty three
protein targets. So this is a brilliant study. Hence I
got into the journal Nature, which is one of the
top journals around. Now what they find headlines is that
on average, participants lost about five point seven kilos, which
(05:12):
is roughly twelve pounds for those who use that currency. Now,
most of the stuff that they lost was subcutaneous fat,
the fat just under the skin, and they lost some
lean muscle tissue. But interestingly, their muscle mass rebranded quickly
(05:32):
once the food was reintroduced, whereas the fat loss was
sustained and somewhat surprisingly, they didn't lose a lot of
visceral fat. Most of the fat that they lost, as
I said, was subcutaneous in nature. Now, one other thing
is that is these guys weren't weren't huge. Their average
WEE was seventy seven point five kilos. Now it was
(05:54):
a mixture of men and women, but their average BMI
was twenty five point four, which is just above the
sort of cutoff of twenty five for overweight. So they
were certainly by no means obese. But they lost five
point seven kilos. So that is probably equivalent of, just
(06:15):
off the top of my head, about eight percent of
their weight loss, which is.
Speaker 2 (06:19):
Very very significant.
Speaker 1 (06:21):
So let's that I go and talk about the other
things that they measured. Their blood glucose dropped, their fatty
acids rose, and their ketones climbed steadily throughout the week,
and that confirmed the metabolic switch from glucose to fat
and ketone metabolism. And that's pretty standard for fasting, and
(06:43):
it is one of the major benefits of people doing fasting,
particularly time restricted feeding on the sixteen to eight is
they develop what we call metabolic flexibility, where your body
can switch from burning glucose to burning fat, and this
is hugely important in this metabolic flexibility, and it's one
(07:04):
of the biggest detrimental effects of our modern lifestyle about
having food always available is that we tend to stay
in glucose metabolism and it's not that good for us
from a long term perspective. So that ability to switch
over into ketones is pretty key. And they measured ketones
(07:25):
such as beta hydroxy butyrate and beta hydroxy buryate is
known to trigger a lot of different health benefits. But
here's the big thing was the proteomic response, the deep
systemic shifts in proteins across multiple organs, and that shift
didn't really start until day three. In fact, over a
(07:47):
third of all proteins measured, which was more in a
thousand and changed significantly during the week. And these included
proteins involved in immune signaling, tissue scaffolding, lip metabolism, hormones,
and even brain related proteins like tenaskin art which is
(08:08):
critical for maintaining synaptic plasticity. And so this wasn't just
about weight loss this study. It was about multi organ recalibration.
And the timeline is really important. Day one and day
two seemed to be just a metabolic adjustment, and from
day three onwards the body then appears to begin a
(08:31):
deeper systemic reset. Now, the companion commentary in another paper
published in Nature Metabolism. So this is a bunch of
other researchers doing a commentary on it. It took it
a step further, and the title of that was the
weight loss independent Benefits of fasting, and that free as
(08:53):
weight loss independent.
Speaker 2 (08:54):
That's pretty key.
Speaker 1 (08:55):
We often assume that fasting is just good for us
because it reduces calories and weight loss, and whilst that's true,
this commentary that appeared in Nature Metabolism highlighted that many
of the benefits observed in the proteomic data are not
tightly correlated with how much weight someone lost. In other words,
(09:17):
fasting isn't just dadding with zero calories. It's doing something
unique to our biology. These other researchers pointed out that
some of the earliest protein changes oc curved before much
of the weight had actually been lost, and many of
the shifts, particularly in immune regulation, in mitochondrial function and
(09:39):
stress response proteins, don't map neatly into the fat loss story.
And this means that fasting may offer therapeutic potential beyond
obesity for conditions that are linked to inflammation, autoimmune conditions,
or neurological health as well. So when you hear people
say that fastings just another way to cut calories, this
(10:03):
paper and the associated commentary strongly suggest otherwise. They are
unique biological processes triggered only when you completely abstain from
food for a few days or more. Now, one of
the most fascinating things is how feased these adaptations actually are.
Speaker 2 (10:22):
In the first couple of days, they.
Speaker 1 (10:24):
Found that the changes were relatively modest. A few hormones
like grellin or thorroid hormones shift a bit, but nothing
really dramatic. But by day three the proteonomic landscape transformed.
Hundreds of proteins suddenly begin to increase or decrease, initiating
cascades of tissue remodeling, immune modulation, and metabolic rewiring. And
(10:50):
I want you to think of it like this. Fasting
has a switch point, and it seems to be about
seventy two hours in And that is why the study
authors and commentary emphasize the calming fasting routines like intermittent fasting,
time restricted feeding or twenty four are fast may not
trigger and probably don't trigger these deeper metabolic adaptations. You
(11:16):
might need at least three to four days to start
unlocking them.
Speaker 2 (11:20):
So what does this mean. Here's how I would frame it.
Speaker 1 (11:24):
By day three, you're entering the doorway of metabolic shift.
You've switched from glucose to ketones. You've suppressed leptin, down
regulated thyroid signaling a bit, and begun to trigger some
of the weight loss independent protein shifts across metabolism. By
(11:44):
day four, you seem to be consolidating these early adaptations.
Your ketones are picking fatty acids plateau, and some immune
and brain related changes begin. But and this is crucial,
many of the later adaptations, especially around tissue remodeling, the
extracellular matrix and deep brain signaling proteins, really start to
(12:08):
accelerate from day five to day seven.
Speaker 2 (12:10):
Now here's where I just want to add my lanes
to it. And it's only my thoughts, but.
Speaker 1 (12:17):
I think you would be able to accelerate the positive
effects of the fast by taking k tone esther supplements.
So these are supplements that are now commercially available that
will very quickly in the absence of food and switch
you over from glucose metabolism to ketone metabolism to metabolism
(12:41):
from fat, and in that driving you into ketosis triggers
the release of being hydroxy buriod and other ketones, which
I think seem to signal a lot of these changes.
But this is just my theory and it's something that
should tested. And actually I'm going to talk to Grant
(13:02):
Schofield and my partner in the Hormesis Lab about doing
just this and seeing if we can tweak or accelerate
the timeline of those really really important metabolic shifts.
Speaker 2 (13:17):
And the other.
Speaker 1 (13:18):
Comment that I had, I initially when I read the paper,
I thought, I'm guessing that these guys are older adults,
because it didn't actually say in the paper. But then
when I rechecked it, it said twelve and young healthy adults,
So they weren't older adults, which is actually surprising for
(13:39):
me because I believe that a lot of the benefits
of fasting would really be in your forties and your
fifties and your sixties. It is very frustrating that they
did not give the ads. And I checked the supplementary
materials online looking for the AEDs of the participants, but
(14:00):
it didn't give it, which I don't know why they
did not do that, but anyway, it is what it is.
But what that would appear is that these benefits are
not just for old bastards like me when everything starts
to fall apart.
Speaker 2 (14:16):
Now we know, and I have talked about it before, and.
Speaker 1 (14:20):
That there are waves of aging that happen with us,
and the first wave seems to be in the early forties,
and then there's another way around sixty. There's potentially another
way around the age of eighty. But the fact that
they said they were young, healthy adults, that suggests to
me that they were in their twenties or their thirties
and still had significant benefits in metabolism, proteins involved in inflammation,
(14:47):
involved in immunity, and all of these things.
Speaker 2 (14:50):
So this is.
Speaker 1 (14:51):
Surprising, but again quite frustrating, because I'd love to know
the age of the people and whether there were any
age related differences them. But that notwithstanding, I do think
that you could potentially shorten that seven day fast down
(15:12):
by taking a key tone ester right at the start,
and you could get yourself some keytone strips from the
chemist and just measure and if you go into ketosis
on day one. That to me would appear to accelerate
it by a couple of days. So you might get
away with a five day fast rather than a seven
day fast.
Speaker 2 (15:30):
But that's only my thinking, and I do.
Speaker 1 (15:32):
Want to run an experiment and we'll talk to Grant
about that. So but what is clear is that a
three or a four day fast is certainly not a
waste of time, particularly if you take a key tone ester.
Speaker 2 (15:46):
It is a powerful intervention.
Speaker 1 (15:48):
And a three to four day water fast is a
shit loat easier than a seven day waterfast.
Speaker 2 (15:52):
So I've done I've done a.
Speaker 1 (15:54):
Five day one, but I've also done ten days that
was rather forced on combat survival and resistance to interrogation training,
which I don't recommend you can bin all of that.
But a seven day one, I think would be a
shitload harder. So if we can shorten this process a
(16:14):
little bit and get all those protein changes, that would
be really interesting. But also what happens in a ten
day fast is that even better than a seven day fast,
And the fact that these guys were able to recoup
the link tissue, the muscle that they lost, and they
had no loss and bone loss, but they were able
(16:36):
to after three days, I think recoop their muscle. That
is actually a good thing. So let's talk about pros
and cons just before we sum up.
Speaker 2 (16:45):
So the benefits here, they is very clear.
Speaker 1 (16:50):
There are weight loss independent benefits of our prolonged fast.
There's unique shifts in immune stress and neural proteins, and
there is significant subcutaneous fat loss while spurring bone mass,
but some loss of muscle. Now, it didn't say that
these guys did resistance training. That's another thing I would
(17:11):
throw in there. If you did some resistance training on
those days, just be aware that your kind of top
end will be gone, but you could minimize the loss
in muscle if you did that. And then there's real
good potential therapeutic angles here for conditions like epilepsy. We
know that a chidogenic diet is great for epilepsy, but
(17:33):
also autoimmune diseases. And I've talked to a number of
people I know who have autoimmune diseases, and I've recommended
a five day fast or a five day fasting mimicking
diet in conjunction with regular cold water exposure. But there's
also benefits here for potential cardiovascular disease and even neurodegenerative diseases.
(17:55):
But they're a little bit speculative, and there is this
rebound resilient. As I said, the lean muscle tissue was
largely recovered after refeeding. So let's talk about the drawbacks
and the risk because I've heard a number of people
talking about fasting and how it is risky and dangerous.
So potential drawbacks and risks. Now, I remember these were younger,
(18:16):
healthy adults. So one is hormonal suppression. Thyroid and reproductive
signaling decrease was noticed, and now that's adaptive here, but
if you already have thorroid or hormonal issues, it could
be problematic. And there are some potential issues with coagulation
and bone markers. Now, some of the signals suggested temporary
(18:39):
risks for clotting or bone turnover, but again we don't
know from the long term perspective. And then individual variability,
while there were broad responses were pretty consistent, some protein
shifted differently between participants. Not everyone will have the same
benefit profile now and if any, but it's her doctor,
(19:00):
Stacy Sims. She was on my podcast. She's brilliant. She
talks about women are not small men. And now she
has said previously that women shouldn't be fasting. I think
this study shows that that's not the case. What I
would add to the stacy sims women are not small men.
Not all women are equal, and not all men are equal.
And this study showed that there were individual differences, so
(19:21):
not everybody is going to get the same benefit profile.
And then finally, adherence and safety. Seven day water fast
is mentally and physically demanding and for anyone with medical conditions,
it should absolutely be supervised by your doctor. Now, some
people might think, and I know health professionals who say
fasting is dangerous and you shouldn't fast more than twelve
(19:45):
hours and it can be really dangerous. But here's where
a history lesson comes in. I am looking at on
my computer right now. I am looking at a research
paper in the Postgraduate Medical Journal of March nineteen seventy three,
and it's a case report and the title of the
(20:07):
paper features of a successful therapeutic fast of three hundred
and eighty two days duration. This was back in the
nineteen seventies. A Scottish dude weighing four hundred and fifty
six pounds that's over two hundred kilos went to his
doc and.
Speaker 2 (20:25):
Said, I'm a bit fat.
Speaker 1 (20:26):
I think I need to stop eating for a while,
and they agreed for him to do a medically supervised fast.
Speaker 2 (20:33):
Wasn't intended to be that long, but he took.
Speaker 1 (20:36):
After a while, he took daily vitamins and minerals and
had regular check ins, but no calories other than after
I can't remember how long. It was quite a long
long time. He started adding a little bit of milk
in his tea. He lost a whopping two hundred and
seventy six pounds. What's that one hundred and twenty two
hundred and thirty kilos. He reached a healthy weight, and remarkably,
(20:57):
he maintained the vast majority of his weight loss years Now.
Speaker 2 (21:01):
Even when his blood glucose.
Speaker 1 (21:03):
Dropped the levels that would terrify most doctors today, and
that was around thirty milligrams per DECI leader, he remained alert, functional,
and symptom three because he completely shifted into ketosis. Now,
I'm not suggesting that you should go out and fast
for a year, but this case study shows that the
human body is remarkably well adapted to prolonged periods without food. Now,
(21:26):
clearly he had a lot of reserve that he could
live off. But the short of fast three days, four days,
seven days, that really appeels in comparison to what's physiologically
possible for lots of humans, and there are routinely there
are monks who fast for one hundred days, right, So
(21:47):
I would not be concerned unless you have current health conditions.
Speaker 2 (21:52):
But again, go and check with your doctor if you're
keen on doing this.
Speaker 1 (21:57):
So if you're worried you're going to die without food
for forty eight hours, you'll be all right. And the
body is built to endure, adapt and even thrive provided
that fast is done responsibly. So what's the takeout? Fasting
is not just for weight loss. It triggers system wide
changes in our proteum, and there are unique weight loss
(22:20):
independent biological effects that appear to be very beneficial for
lots of our organs or immune system. All of these things.
The timing matters. The deepest systemic shifts begin after day three.
But with my little Asterrex, what happens if you take
a keto nester, But they continue to build across days
five to seven, and we just don't know if day
(22:44):
seven is the peak benefits. It may be that ten
days is even more beneficial now. The other one is
as always, fasting isn't for everyone if you have health conditions,
if you take medications, or you're underweight, So one of
the exclusion criteria here was females couldn't be below fifteen
percent body fat and the meals couldn't below twelve percent
(23:05):
body fat. So please consult the doctor before attempting it
if you have current health conditions, if you take medications,
or if you're pretty lean to start with. But for
those curious, discipline and healthy enough to try fasting, especially
prolonged fasting, may be one of the most profound, low cost,
ancient tools that we have for resetting the body. That's
(23:28):
it for this week, folks, Catch you next time.
Hey, everyone, Welcome to another edition of Wisdom Wednesdays. And
just before we start, another shameless plug for my book,
The Hardiness Effect, How to Grow From Stress, Optimize your
health and Live Longer, is now on pre sel with
a twenty six percent discount on Amazon, so jump amongst
it and get involved. I am also shortly going to
(00:32):
be announcing a hardiness intervention to coincide with my shift
towards All Things Hardiness, where I'm actually going to do
my first ever public workshop. But I'm going to combine
that public workshop with a six week program in the app,
My Hardiness App, which is very closely mirrored to the
(00:54):
research study I did in my PhD where we took
a bunch of busy corporate did a day's hardiness training
with them.
Speaker 2 (01:03):
They had eight weeks on the app.
Speaker 1 (01:04):
We measured their cognitive function, their cognitive performance, their hardiness,
their mood, their gratitude, their stress, and their resilience and
had statistically significant improvements in almost everything. And I am
now going to bring this to the general public, so
standby for an announcement. There will be a one day
workshop in Melbourne, probably at the end of October start
(01:28):
of November, but what's this space?
Speaker 2 (01:31):
So now on with the podcast.
Speaker 1 (01:33):
So today we're going to go deep into one of
the oldest practices knowing to humankind, and that is fasting.
As you probably were, it's been used across cultures for religious, spiritual,
and therapeutic purposes for thousands of years, and in recent years,
intermittent fasting and time restricted eating have taken the health
(01:56):
world by storm.
Speaker 2 (01:58):
But today we're not going to talk about.
Speaker 1 (02:00):
Skipping breakfast or doing sixteen eight or any of those things.
We're talking about a prolonged water fast only and specifically
going to look at the effects of a seven day
fast and what it does to the human body right
down to the level of thousands of proteins circulating in
(02:20):
your blood. And we're going to explore a groundbreak and
study that was just published in Nature Metabolism, and also
some other commentary that was published again in the journal Nature,
really looking at the comparison of shorter fast the three
or four day waterfast that many of you have tried,
(02:40):
with some longer fasting. And by the end of this episode,
I hope you'll have a pretty nuanced understanding of the benefits,
the risk, and the biological effects of extended fasting, and
a bit of clarity about were, if any were it
might fit in your own health journey.
Speaker 2 (02:58):
So let's start with the research.
Speaker 1 (03:00):
A team of scientists from Berlin, Cambridge, Copenhagen and Oslo
recruited twelve healthy young volunteers. Five of them were women
and seven were men, and this is important because it
was both sexes.
Speaker 2 (03:14):
And they asked them.
Speaker 1 (03:15):
To do something simple but definitely challenging for anybody who's
ever done it. Drink only water for seven days straight,
no calories whatsoever. And throughout the week, the researchers collected
blood samples every morning and use the cutting edge proteumic
platform to measure nearly three thousand proteins circulating in their plasma. Now,
(03:40):
anybody who's heard me talk about the twelve major hallmarks
of aging, one of those major hallmarks is loss of proteostasis.
So basically, changes in how these proteins that circulate in
our blood changes in them and how those changes actually
accelerate to aging. And proteins are really the building blocks
(04:03):
of all life. So in this study, they also tracked
their body weight, their fat mass, their lean mass, their
hormones and then metabolites like ketone bodies and fatty acids.
So let's talk about what happened. So, as I said,
twelve participants, five women and seven men, and they measured
(04:24):
them before, during, and after a prolonged seven day fast
with absolute calorie restriction, and they can just drink as
much water as they wanted. So they took fasting blood
early in the morning between six and nine am from
all participants two days prior to the intervention. Then they
took it daily during the intervention and then again three
(04:47):
days after stopping the intervention, and in their plasma they
looked at a total of twenty nine and twenty three
protein targets. So this is a brilliant study. Hence I
got into the journal Nature, which is one of the
top journals around. Now what they find headlines is that
on average, participants lost about five point seven kilos, which
(05:12):
is roughly twelve pounds for those who use that currency. Now,
most of the stuff that they lost was subcutaneous fat,
the fat just under the skin, and they lost some
lean muscle tissue. But interestingly, their muscle mass rebranded quickly
(05:32):
once the food was reintroduced, whereas the fat loss was
sustained and somewhat surprisingly, they didn't lose a lot of
visceral fat. Most of the fat that they lost, as
I said, was subcutaneous in nature. Now, one other thing
is that is these guys weren't weren't huge. Their average
WEE was seventy seven point five kilos. Now it was
(05:54):
a mixture of men and women, but their average BMI
was twenty five point four, which is just above the
sort of cutoff of twenty five for overweight. So they
were certainly by no means obese. But they lost five
point seven kilos. So that is probably equivalent of, just
(06:15):
off the top of my head, about eight percent of
their weight loss, which is.
Speaker 2 (06:19):
Very very significant.
Speaker 1 (06:21):
So let's that I go and talk about the other
things that they measured. Their blood glucose dropped, their fatty
acids rose, and their ketones climbed steadily throughout the week,
and that confirmed the metabolic switch from glucose to fat
and ketone metabolism. And that's pretty standard for fasting, and
(06:43):
it is one of the major benefits of people doing fasting,
particularly time restricted feeding on the sixteen to eight is
they develop what we call metabolic flexibility, where your body
can switch from burning glucose to burning fat, and this
is hugely important in this metabolic flexibility, and it's one
(07:04):
of the biggest detrimental effects of our modern lifestyle about
having food always available is that we tend to stay
in glucose metabolism and it's not that good for us
from a long term perspective. So that ability to switch
over into ketones is pretty key. And they measured ketones
(07:25):
such as beta hydroxy butyrate and beta hydroxy buryate is
known to trigger a lot of different health benefits. But
here's the big thing was the proteomic response, the deep
systemic shifts in proteins across multiple organs, and that shift
didn't really start until day three. In fact, over a
(07:47):
third of all proteins measured, which was more in a
thousand and changed significantly during the week. And these included
proteins involved in immune signaling, tissue scaffolding, lip metabolism, hormones,
and even brain related proteins like tenaskin art which is
(08:08):
critical for maintaining synaptic plasticity. And so this wasn't just
about weight loss this study. It was about multi organ recalibration.
And the timeline is really important. Day one and day
two seemed to be just a metabolic adjustment, and from
day three onwards the body then appears to begin a
(08:31):
deeper systemic reset. Now, the companion commentary in another paper
published in Nature Metabolism. So this is a bunch of
other researchers doing a commentary on it. It took it
a step further, and the title of that was the
weight loss independent Benefits of fasting, and that free as
(08:53):
weight loss independent.
Speaker 2 (08:54):
That's pretty key.
Speaker 1 (08:55):
We often assume that fasting is just good for us
because it reduces calories and weight loss, and whilst that's true,
this commentary that appeared in Nature Metabolism highlighted that many
of the benefits observed in the proteomic data are not
tightly correlated with how much weight someone lost. In other words,
(09:17):
fasting isn't just dadding with zero calories. It's doing something
unique to our biology. These other researchers pointed out that
some of the earliest protein changes oc curved before much
of the weight had actually been lost, and many of
the shifts, particularly in immune regulation, in mitochondrial function and
(09:39):
stress response proteins, don't map neatly into the fat loss story.
And this means that fasting may offer therapeutic potential beyond
obesity for conditions that are linked to inflammation, autoimmune conditions,
or neurological health as well. So when you hear people
say that fastings just another way to cut calories, this
(10:03):
paper and the associated commentary strongly suggest otherwise. They are
unique biological processes triggered only when you completely abstain from
food for a few days or more. Now, one of
the most fascinating things is how feased these adaptations actually are.
Speaker 2 (10:22):
In the first couple of days, they.
Speaker 1 (10:24):
Found that the changes were relatively modest. A few hormones
like grellin or thorroid hormones shift a bit, but nothing
really dramatic. But by day three the proteonomic landscape transformed.
Hundreds of proteins suddenly begin to increase or decrease, initiating
cascades of tissue remodeling, immune modulation, and metabolic rewiring. And
(10:50):
I want you to think of it like this. Fasting
has a switch point, and it seems to be about
seventy two hours in And that is why the study
authors and commentary emphasize the calming fasting routines like intermittent fasting,
time restricted feeding or twenty four are fast may not
trigger and probably don't trigger these deeper metabolic adaptations. You
(11:16):
might need at least three to four days to start
unlocking them.
Speaker 2 (11:20):
So what does this mean. Here's how I would frame it.
Speaker 1 (11:24):
By day three, you're entering the doorway of metabolic shift.
You've switched from glucose to ketones. You've suppressed leptin, down
regulated thyroid signaling a bit, and begun to trigger some
of the weight loss independent protein shifts across metabolism. By
(11:44):
day four, you seem to be consolidating these early adaptations.
Your ketones are picking fatty acids plateau, and some immune
and brain related changes begin. But and this is crucial,
many of the later adaptations, especially around tissue remodeling, the
extracellular matrix and deep brain signaling proteins, really start to
(12:08):
accelerate from day five to day seven.
Speaker 2 (12:10):
Now here's where I just want to add my lanes
to it. And it's only my thoughts, but.
Speaker 1 (12:17):
I think you would be able to accelerate the positive
effects of the fast by taking k tone esther supplements.
So these are supplements that are now commercially available that
will very quickly in the absence of food and switch
you over from glucose metabolism to ketone metabolism to metabolism
(12:41):
from fat, and in that driving you into ketosis triggers
the release of being hydroxy buriod and other ketones, which
I think seem to signal a lot of these changes.
But this is just my theory and it's something that
should tested. And actually I'm going to talk to Grant
(13:02):
Schofield and my partner in the Hormesis Lab about doing
just this and seeing if we can tweak or accelerate
the timeline of those really really important metabolic shifts.
Speaker 2 (13:17):
And the other.
Speaker 1 (13:18):
Comment that I had, I initially when I read the paper,
I thought, I'm guessing that these guys are older adults,
because it didn't actually say in the paper. But then
when I rechecked it, it said twelve and young healthy adults,
So they weren't older adults, which is actually surprising for
(13:39):
me because I believe that a lot of the benefits
of fasting would really be in your forties and your
fifties and your sixties. It is very frustrating that they
did not give the ads. And I checked the supplementary
materials online looking for the AEDs of the participants, but
(14:00):
it didn't give it, which I don't know why they
did not do that, but anyway, it is what it is.
But what that would appear is that these benefits are
not just for old bastards like me when everything starts
to fall apart.
Speaker 2 (14:16):
Now we know, and I have talked about it before, and.
Speaker 1 (14:20):
That there are waves of aging that happen with us,
and the first wave seems to be in the early forties,
and then there's another way around sixty. There's potentially another
way around the age of eighty. But the fact that
they said they were young, healthy adults, that suggests to
me that they were in their twenties or their thirties
and still had significant benefits in metabolism, proteins involved in inflammation,
(14:47):
involved in immunity, and all of these things.
Speaker 2 (14:50):
So this is.
Speaker 1 (14:51):
Surprising, but again quite frustrating, because I'd love to know
the age of the people and whether there were any
age related differences them. But that notwithstanding, I do think
that you could potentially shorten that seven day fast down
(15:12):
by taking a key tone ester right at the start,
and you could get yourself some keytone strips from the
chemist and just measure and if you go into ketosis
on day one. That to me would appear to accelerate
it by a couple of days. So you might get
away with a five day fast rather than a seven
day fast.
Speaker 2 (15:30):
But that's only my thinking, and I do.
Speaker 1 (15:32):
Want to run an experiment and we'll talk to Grant
about that. So but what is clear is that a
three or a four day fast is certainly not a
waste of time, particularly if you take a key tone ester.
Speaker 2 (15:46):
It is a powerful intervention.
Speaker 1 (15:48):
And a three to four day water fast is a
shit loat easier than a seven day waterfast.
Speaker 2 (15:52):
So I've done I've done a.
Speaker 1 (15:54):
Five day one, but I've also done ten days that
was rather forced on combat survival and resistance to interrogation training,
which I don't recommend you can bin all of that.
But a seven day one, I think would be a
shitload harder. So if we can shorten this process a
(16:14):
little bit and get all those protein changes, that would
be really interesting. But also what happens in a ten
day fast is that even better than a seven day fast,
And the fact that these guys were able to recoup
the link tissue, the muscle that they lost, and they
had no loss and bone loss, but they were able
(16:36):
to after three days, I think recoop their muscle. That
is actually a good thing. So let's talk about pros
and cons just before we sum up.
Speaker 2 (16:45):
So the benefits here, they is very clear.
Speaker 1 (16:50):
There are weight loss independent benefits of our prolonged fast.
There's unique shifts in immune stress and neural proteins, and
there is significant subcutaneous fat loss while spurring bone mass,
but some loss of muscle. Now, it didn't say that
these guys did resistance training. That's another thing I would
(17:11):
throw in there. If you did some resistance training on
those days, just be aware that your kind of top
end will be gone, but you could minimize the loss
in muscle if you did that. And then there's real
good potential therapeutic angles here for conditions like epilepsy. We
know that a chidogenic diet is great for epilepsy, but
(17:33):
also autoimmune diseases. And I've talked to a number of
people I know who have autoimmune diseases, and I've recommended
a five day fast or a five day fasting mimicking
diet in conjunction with regular cold water exposure. But there's
also benefits here for potential cardiovascular disease and even neurodegenerative diseases.
(17:55):
But they're a little bit speculative, and there is this
rebound resilient. As I said, the lean muscle tissue was
largely recovered after refeeding. So let's talk about the drawbacks
and the risk because I've heard a number of people
talking about fasting and how it is risky and dangerous.
So potential drawbacks and risks. Now, I remember these were younger,
(18:16):
healthy adults. So one is hormonal suppression. Thyroid and reproductive
signaling decrease was noticed, and now that's adaptive here, but
if you already have thorroid or hormonal issues, it could
be problematic. And there are some potential issues with coagulation
and bone markers. Now, some of the signals suggested temporary
(18:39):
risks for clotting or bone turnover, but again we don't
know from the long term perspective. And then individual variability,
while there were broad responses were pretty consistent, some protein
shifted differently between participants. Not everyone will have the same
benefit profile now and if any, but it's her doctor,
(19:00):
Stacy Sims. She was on my podcast. She's brilliant. She
talks about women are not small men. And now she
has said previously that women shouldn't be fasting. I think
this study shows that that's not the case. What I
would add to the stacy sims women are not small men.
Not all women are equal, and not all men are equal.
And this study showed that there were individual differences, so
(19:21):
not everybody is going to get the same benefit profile.
And then finally, adherence and safety. Seven day water fast
is mentally and physically demanding and for anyone with medical conditions,
it should absolutely be supervised by your doctor. Now, some
people might think, and I know health professionals who say
fasting is dangerous and you shouldn't fast more than twelve
(19:45):
hours and it can be really dangerous. But here's where
a history lesson comes in. I am looking at on
my computer right now. I am looking at a research
paper in the Postgraduate Medical Journal of March nineteen seventy three,
and it's a case report and the title of the
(20:07):
paper features of a successful therapeutic fast of three hundred
and eighty two days duration. This was back in the
nineteen seventies. A Scottish dude weighing four hundred and fifty
six pounds that's over two hundred kilos went to his
doc and.
Speaker 2 (20:25):
Said, I'm a bit fat.
Speaker 1 (20:26):
I think I need to stop eating for a while,
and they agreed for him to do a medically supervised fast.
Speaker 2 (20:33):
Wasn't intended to be that long, but he took.
Speaker 1 (20:36):
After a while, he took daily vitamins and minerals and
had regular check ins, but no calories other than after
I can't remember how long. It was quite a long
long time. He started adding a little bit of milk
in his tea. He lost a whopping two hundred and
seventy six pounds. What's that one hundred and twenty two
hundred and thirty kilos. He reached a healthy weight, and remarkably,
(20:57):
he maintained the vast majority of his weight loss years Now.
Speaker 2 (21:01):
Even when his blood glucose.
Speaker 1 (21:03):
Dropped the levels that would terrify most doctors today, and
that was around thirty milligrams per DECI leader, he remained alert, functional,
and symptom three because he completely shifted into ketosis. Now,
I'm not suggesting that you should go out and fast
for a year, but this case study shows that the
human body is remarkably well adapted to prolonged periods without food. Now,
(21:26):
clearly he had a lot of reserve that he could
live off. But the short of fast three days, four days,
seven days, that really appeels in comparison to what's physiologically
possible for lots of humans, and there are routinely there
are monks who fast for one hundred days, right, So
(21:47):
I would not be concerned unless you have current health conditions.
Speaker 2 (21:52):
But again, go and check with your doctor if you're
keen on doing this.
Speaker 1 (21:57):
So if you're worried you're going to die without food
for forty eight hours, you'll be all right. And the
body is built to endure, adapt and even thrive provided
that fast is done responsibly. So what's the takeout? Fasting
is not just for weight loss. It triggers system wide
changes in our proteum, and there are unique weight loss
(22:20):
independent biological effects that appear to be very beneficial for
lots of our organs or immune system. All of these things.
The timing matters. The deepest systemic shifts begin after day three.
But with my little Asterrex, what happens if you take
a keto nester, But they continue to build across days
five to seven, and we just don't know if day
(22:44):
seven is the peak benefits. It may be that ten
days is even more beneficial now. The other one is
as always, fasting isn't for everyone if you have health conditions,
if you take medications, or you're underweight, So one of
the exclusion criteria here was females couldn't be below fifteen
percent body fat and the meals couldn't below twelve percent
(23:05):
body fat. So please consult the doctor before attempting it
if you have current health conditions, if you take medications,
or if you're pretty lean to start with. But for
those curious, discipline and healthy enough to try fasting, especially
prolonged fasting, may be one of the most profound, low cost,
ancient tools that we have for resetting the body. That's
(23:28):
it for this week, folks, Catch you next time.
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