Dr Jason Fung ,nephrologist and best-selling
author shares his experiences utilizing an
individualized approach to fasting
to successfully treat thousands of
overweight metabolically ill and
diabetic patients
and why being a doctor who specializes
in kidney disease
gives him a unique insight into early
indications of metabolic disease
let’s listen to Dr Jason Fung.
Dr. Jason Fung’s Eating/Fasting Schedule
I don’t eat breakfast a lot of the days
of the week so
when i have something at lunchtime then
i’ll often just kind of just keep
working and
once you get used to it it’s really not
very difficult because your body will
simply
take the calories it needs from your
stores of energy which is your body fat
and the glycogen which is stored away
so it’s a completely natural process and
when there’s time then i go and eat and
it makes it so much easier you don’t
have to obsess all the time about
oh i don’t have time what can i eat and
then you wind up going to
the local donut store and then oh
there’s just muffins so then you
reference and you know that that’s not
good for you but then you feel this
pressure
to eat there’s all this pressure on
people oh you’re not
hungry but you must eat it’s like well
eating when you’re not hungry is not a great
weight loss strategy if you look at the
what happens when you wake up it’s very
interesting because there is a counter regulatory surge which happens
just before you wake up so somewhere
around 4.30 a.m your body releases
certain hormones which are counter
regulatory hormones
that is they run counter to insulin so
these are the sympathetic nervous system
gets activated growth hormone
noradrenaline for example so these all
spike just before you wake up and the whole
point of it is that they are actually activating your body
for the day ahead and one of the things that these counter
regular hormone counter regulatory hormones do
is they stimulate your liver to pump out some glucose so in fact
you don’t have to eat to get ready for the day
your body’s already done that for you. If
you start to eat well that’s fine if you
like to eat breakfast it’s fine but you
don’t
have to, then you don’t.
Lots of different cultures have
done all kinds of different eating
regimens throughout history
and people have done well on all
different ones so early. Simply
if you look at for example circadian
rhythm of hunger i actually think that’s
very interesting because if you
take people and simply measure their
hunger over 24 hours there is a
tendency to go in certain patterns and
the rhythm is that your hunger is
actually lowest at somewhere around 7 30 8
at 8 o’clock in the morning so again and
that’s because of the
counter regulatory surge and the fact is
that
the hormones is what determines your
hunger because 8 a.m
is usually the longest period before
you’ve eaten because you’ve often
not eaten all night so it may be 12 14
hours since you’ve eaten yet
your hunger is actually the lowest that
it is through the day
so again that’s why a lot of children
don’t feel like eating breakfast
and so on and the only reason they start
eating breakfast is that we force them
and we tell them
that you got to eat breakfast you got
eat breakfast garbage breakfast and it’s
okay if you want to eat breakfast but
what you want to avoid is eating all
this processed sort of highly refined foods
that are so convenient and have taken
over the breakfast aisle so to speak
because they’re so easy we can grab them
and go muffins and donuts and all these
pop-tarts all these sort of things that
are super unhealthy for us
because we don’t want to cook bacon and
eggs in the morning it’s like who’s got
time for that you gotta cook clean eat
all this sort of stuff
right so even if you look at the
circadian rhythm
if you’re again if you’re the least
hungry at 8am
why would you force yourself to eat it
doesn’t make any sense
it’s based on people who have
said that oh it’s going to keep you full
throughout the day it’s going to both
boost your metabolism
the data behind those claims is very
very sketchy. People get brow beaten into oh
you must eat it, you must eat. It’s like, no
there’s lots of different options- you
can eat if you want and you can make it
work for you and
if you’re really not hungry at breakfast
then you don’t want to eat and you’re
way too busy, you want to rush out the door to get to
work and get to school, yes you can
just skip it and go to lunch time, it’s
okay.
What’s interesting is the very word
itself
“breakfast”- it’s the meal that breaks your
fast. It’s not the “oh you must eat as soon as
you wake up before your feet hit the
ground” sort of thing.
You can break your fast at any point, you
can break it at 8am, you could break it
at 11am, it makes no difference
and the other thing that’s very
interesting- a word is that
what it implies is that you actually
have to fast in order to be able to
break your fast
so what this tells us is that
it’s part of the natural cycle of life
you have to eat
but you have to fast fasting is merely
the absence of eating
so if you have a period of time that’s
when you eat and you have a period of
time where you should fast
right you don’t eat all the time that’s
not a good weight loss strategy either
yeah
we get told again and again oh
before your feet hit the hit the hit the
ground you got to start shoving food in
your mouth
and then oh you can’t you can’t you have
to eat all the way up until you go to
bed
you know six or seven eight nine ten
meals in the day
oh that’s gonna make you healthy where
is your period of fat
so this was described by a lot of the
physiologists and
many of these studies are very old and
it basically
is a process of moving from
storage of food energy to burning food
energy so
what happens is that when you eat
insulin goes up and insulin is a hormone
it’s essentially a nutrient sensor so a
lot of things other than just
carbohydrates a lot of proteins for
example will also stimulate insulin
when you eat the insulin goes up and it
tells your body that you need to store
food energy because you’re eating and
you’ve got more food energy
than you actually need so some of it
goes to open up the cells to glucose for
example and that’s what we tend to think
about for insulin is that
it lets the cells use the glucose but
the other thing it does is it stops
lipolysis which is the burning of fat
and glycogenolysis which is the
storage so you store sugar
in the form of glycogen in the liver so
glycogen is long chains of glucose the
liver
packages them all together and stores it
in the liver
and this is why you don’t die when you
go to sleep every single night is
because your body can store some of this
food energy
so when you’re not eating it will bring
it back out
plants for example will link all these
chains of glucose together is starches
so amylopectin for example there’s
amylopectin a b
and c so there’s different forms of
starches so for example
white bread white flour uses amylopectin
a and this is the wheat
that puts all this glucose together
so that’s what plants do they use starch
and humans use glycogen and lots of
mammals use glycogen as well
but essentially you can think of it as
stored sugar because that’s what it is
and
the body has two storage forms of energy
it can store glycogen
and when that’s full you can’t store any
more because the liver
simply can’t hold it so your body then
turns to storing fat and this is the
process of de novo lipogenesis
so de novo is a word from latin means
from new lipogenesis lipo means fat
genesis means the creation of so it’s
the
creation of new fat but it’s the
creation of new fat from carbohydrates
dietary fat doesn’t actually do this it
actually just gets absorbed directly and
goes into your fat cells
the excess carbohydrates if you take a
lot of carbohydrates
it gets turned into glycogen it gets
stored
and then body fat so there are two
complementary
storage systems because they fulfill
different roles in the body
the glycogen is easily accessible that
is the body can kind of move in and out
of glycogen very easily
but there’s a limited amount body fat is
much
harder to get at but it has unlimited
storage so
the analogy i sometimes use is it’s kind
of like a refrigerator
and a basement freezer like a chest
freezer the refrigerator it’s right
there it’s easy to put food
in it’s easy to take food out but
once you’re full you’re full the freezer
in the basement
has unlimited capacity that is you can
put several freezers downstairs but it’s
harder to get to
and that’s how the body stores energy as
you stop to eat so
the process of fasting goes through
several phases so
when you eat insulin goes up you store
food energy in those various forms
you’ll notice of course that protein is
not stored as energy
if you eat a lot of protein then your
body uses some of that protein for
building building protein but the excess
actually just gets turned into glucose
because it can’t store
that excess protein so people who are
pounding back
it’s very hard from a dietary standpoint
to eat a high protein diet it tends to
be very unpalatable
yeah natural foods of course are good
but it tends to
when when you’re just eating there’s a
lot of fat in there as well
you just have those shakes and stuff
which is kind of pure protein it’s
it’s it’s not that it’s not that
effective it’s not as effective
as you think it would be but you got to
realize that the bodybuilders are
actually breaking down a lot of muscle
all the time because they’re working out
they’re breaking down the protein so
they they may require
more protein so the first phase the
first phase is the eating phase then you
start to go into
the fasting phase so from about zero to
sort of 24 hours
what happens is that your insulin starts
to fall
so the food that you eat is gone and now
you need to start pulling out energy so
you need to start pulling energy back
out from the body in order to
keep it working so the first place it
goes is the glycogen
so what you see is that your body
continues to burn
glucose up to about 24 hours
at about 24 hours the glycogen stores
run out
and there’s a period of gluconeogenesis
so gluconeogenesis
is again from the word gluco meaning
glucose neo which is new genesis
creation of so it’s the creation of new
glucose
it gets created from protein
so you will break down some protein
and create glucose in order to feed the
cells
you’re ramping up fat oxidation at the
same time but that takes a little bit of
time because as i said the fat
stores are very large or can be very
large but they’re difficult to get at
so it takes a bit of time so in that 24
to 36 hours
you get this period where you’re
actually breaking down some protein
you’re still living off the rest of your
glycogen
and then that’s it at after 36 hours
then you get
the kind of fat oxidation starts to take
over
so protein burning really drops to a
minimal sort of turnover
and then the breakdown and then you
start to see the fat oxidation so
fatty acid levels go up in the blood and
you see fat in the blood and basically
the body lives
off of stored fat from then on says just
physiologically what happens when you
stop eating there are ways to kind of
hack the system so to speak so ketogenic
diets for example
will use very very high fat diets
in order to reduce serum insulin because
insulin is a
one of the sort of master hormones that
controls where your energy
is coming or going so you have to
understand that insulin is essentially a
hormone that tells our body to store our
energy when insulin is low
your body wants to burn energy but you
can’t do both and this is
uh something that’s very interesting is
that
and it makes sense because if you’re
burning energy you don’t want to start
and vice versa so if insulin is high or
it’s low
the the effects are completely opposite
when you’re it’s and there’s something
called the Randle cycle in physiology as
well which is
that when your body is burning glucose
it’s not burning fat and when it’s
burning fat it doesn’t burn glucose
so they actually and this is a
a system that is designed because you
want to kind of use
one fuel or the other and not both at
the same time it’s not very efficient so
that’s why there’s this kind of
sequential move from
burning glucose at first and then fat
and that’s how you kind of hack the
system because if you have
super super super low carbohydrate
intake
you essentially are just providing fat
to the body
obviously there’s some protein there but
mostly fat so
ketogenic diets for example are very
very high fat diets
and because it’s mostly fat your body
turns into burning fat which is why you
get
ketone production so ketones actually
the body does most of the body doesn’t
use ketones
the most of the body directly uses fatty
acids
so the triglycerides so fat body fat is
triglycerides
it’s a glycerol backbone with three
fatty acid chains as you break those
fatty acid chains off
muscles will use fat directly the
glycerol gets turned into glucose
because certain tissues need glucose the
brain is one
but the brain uses way too much glucose
so in order to get
the fuel into the brain your body
produces ketones which can cross the
blood-brain barrier and
feed the brain and that reduces the
reliance on glucose
so that’s where ketosis is that’s where
ketogenic diets are
and that’s how people kind of uh kind of
gain the system to get where they’re
right
now there’s something called the glucose
ketone ratio
so different people actually are quite
different it’s interesting that as your
glucose falls
you expect your ketones to go up but
that’s not what happens in everybody so
some people actually don’t bring up
their ketones and that’s why some people
get this sort of keto flu or they don’t
feel so good when they’re not adapted to
that because their ketones don’t respond
normally
most people will go back to it very
quickly but yeah
if you don’t eat that’s a very fast way
to get into ketosis
if you want for the for the large
majority of people the period
from kind of 24 to 36 hours roughly
where people
are burning protein that’s where people
get the misconception that oh you’re
going to lose muscle you’re going to
burn muscle you’re going to burn muscle
and that’s if you’re just to look at
that you might think that makes sense
but
what they miss is that when you start
refeeding when you
start eating again growth hormone levels
have gone way up so again remember that
growth hormone is one of the
counter-regulatory hormones
right so norepinephrine growth hormone
the sympathetic nervous system all go
up as your insulin goes down so growth
hormone is going up so when you actually
start to eat again
you are starting to rebuild all that
lost
protein but it’s actually better because
what you’ve done
is when you break down those protein
your body actually identifies the kind
of old
junky sort of proteins that it doesn’t
need the cells that it doesn’t need and
gets rid of them
and then rebuilds new ones so it’s
actually a complete renovation
cycle as opposed to leaving that old
protein where it is because if you
continually eat all the time you don’t
have that breakdown that breakdown is
very important
in in medicine for example for new bone
you don’t simply have the bone just
sticking around there’s actually a
continual cycle of renewal of breakdown
and regeneration breakdown and
regeneration and this is
what the fasting does it gives you that
period of breakdown
and regeneration so if you look at
studies
of alternate daily fasting for example
they’ve done studies where they’ve
compared calorie restriction with
alternate daily fasting
over a period of 32 weeks they’ve
measured lean mass at the end of it
in fact the calorie restriction
people their lean mass percentage went
up by 0.5 percent
because they had lost some weight but
the alternate daily fasting room went up
by 2.2
so in other words the fasting group was
four times
better at preserving lean mass which is
directly
contrary absolutely and it’s directly
contrary this is what’s very interesting
because you have studies of
people who are growth hormone deficient
for example older men some people when
they
measure growth hormone and they’re
deficient then when they replace them
they see this
increase in lean mass increase in bone
mass and all these sort of
really beneficial uh things so
i think that that’s what people miss
when they just look at that
period of gluconeogenesis when it’s
breaking down that they miss that
that period where you’re rebuilding just
like if you’re to do a renovation
you have to tear stuff down first you
have to take down uh all the old
cabinets before you put up new cabinets
so if you just look at the teardown you
say oh you’re
that’s terrible but you haven’t looked
at the full cycle of
feast and fast is much more powerful
growth hormone is a
counter regulator hormone so as you eat
insulin goes up so growth hormone goes
down
nothing shuts down growth hormone
secretion like eating
it’s fascinating when they do these long
fast five days and so on
the growth hormone levels just go way
way up
when you see the pattern of
growth hormone secretion get this big
spike in the
beginning of the day that during that
period of
longer fasting that most people have
that 12 to 14 hours where you don’t eat
once you start to fast where you just
don’t eat anything at all
you start to see little spikes of growth
hormone all
all throughout the day so your body’s
actually trying to build and repair and
so on
obviously if you fast forever you’ll die
but
assuming that you eventually eat again
and provide the nutrients that are
needed your body
actually goes into that an anabolic mode
so
it is fascinating and i wouldn’t have
i wouldn’t have thought of it logically
either but this is this is physiology
this is what happens we know
that nothing turns off growth hormone
like eating fasting provides
sort of a lot of different hormonal
changes
there’s changes in obviously insulin and
norepinephrine and growth hormone
sympathetic nervous activation this is
one of the other things that people
don’t necessarily understand is that
if you think about what these hormones
do
they actually activate the body so
sympathetic
nervous system is the so-called
fight-or-flight response
so the body’s actually getting activated
during this period of not eating
norepinephrine or adrenaline which is
noradrenaline
is is pumping up your body it’s not it’s
not shutting it down and this is what
they say oh you don’t eat you’re going
to go into starvation mode your
basal metabolic rate will go down it’s
the complete opposite
when they say you’ll go into starvation
mode they’re actually not just wrong
they’re like 100
wrong because it actually activates so
people come back from
fast and they go whoa i cannot believe
how much energy i
had so yeah because your body is pumping
you full of energy
and if you think about it from an
evolutionary standpoint for example it
makes total sense if you are a hunter
and a caveman
and you don’t eat for a couple of days
and your body starts to shut down
you will never eat again you have no
energy to go out and hunt you have no
energy to catch those rabbits whatever
so your body is simply not that stupid
what it does is it switches energy
sources so it says okay
there’s no more sugar i can’t burn any
sugar i’ve run through my glycogen
i need to switch to body fat not only am
i going to switch to body fat but i need
to
pump you up so that you can go out and
hunt some woolly mammoth
otherwise i’m going to die so that’s
what it does so it it actually burns fat
pumps you up gives you more energy and
it’s like wow that’s
exactly what you want to do because
the the alternative is is is not viable
but
these are physiologic responses these
are is not just kind of hocus pocus you
can measure these hormones and
you know what noradrenaline does it
pumps you up when you measure people
after prolonged fasting their basal
metabolic rate goes
up so for example a study i
i cited which measured metabolic rate
after four days of fasting
shows that when you measure the resting
energy
expenditure at the beginning and the end
of the fast
it’s about 10 higher at the end of those
four days
so your body’s not shutting down it’s
actually being pumped
up so all this stuff about oh you should
never skip
this meal because you’re gonna go into
starvation mode
they’re completely wrong because your
body is pumping
up not not shutting down in fact if you
do calorie restriction we know from
study after study all those studies on
the biggest loser for example
that if you simply try to reduce a few
calories per day so if you say oh i’m
gonna go from 2000 calories to
1600 calories per day we know that your
energy expenditure is going to go from
2000 down to 1600
you will for sure go into so-called
starvation mode by but
it’s the calorie restriction that does
that why because your body
remember has two sources of energy it
has food and it has stored food
or body fat so if you keep eating
insulin is high your body says i need to
store energy
but you only have sixteen hundred
calories your body wants to burn two
thousand but it’s only getting sixteen
hundred
your insulin is high so you can’t store
energy and burn energy so you can’t
so insulin is high so your your fat
stores are locked away
you can’t access those because you’re
still eating all the time
right and what it does is simply i’m
getting 600 calories in
i’m gonna reduce my expenditure to
sixteen hundred so you’ve gone down
the difference when you go down to zero
when you’re it’s it’s about moving that
insulin way down
is that all of a sudden you’ve unlocked
all those stores of fat
the studies show is that almost all
these attempts to
simply restrict your calories now
insulin will go down because
insulin goes down whenever you eat
anything assuming your diet doesn’t
change much but you eat a little less
your insulin will go down slightly
but it’s not going down to like zero low
carbohydrate ketogenic diets do a pretty
good job
also of bringing that insulin level down
and actually you can lower the insulin
levels
even with a high carbohydrate diet it’s
just that it’s not
sugar and refined grains gotcha there’s
lots of ways
beans for there’s a huge difference
between beans for example and white
bread
so they may be the same number of grams
of carbohydrate
but the insulin effect the glucose
effect is
hugely different and you see that on the
glycemic index
so therefore if you look at some
traditional societies for example they
ate a very high carbohydrate diet but
their insulin levels were not bad. The
key, of course, is that they’re not eating
sugar they’re not eating
refined grains and they’re not eating
all the time so
when you do that you can tolerate these
carbohydrate foods
so natural carbohydrate containing foods
unprocessed
sort of things don’t have nearly the
insulin effect as
our sort of refined highly processed
foods that we kind of eat in
modern day North America
so the biggest loser diet is really the
same
standard sort of eat less move more
advice that
physicians and dietitians have given
but it’s sort of that eat less move more
on steroids it’s
eat a lot less and move a lot more so
their
calorie restriction goes down to about
say 1200 calories something like that
they don’t want to be accused of
starving their patients which i think is
ironic because i think if they went to
zero they have done a lot better
and their exercise goes way up because
on the show you see them
exercising and throwing up and all this
kind of stuff
so it’s essentially the same advice that
people
give eat less move more but kind of
jumbo size and what they show is that
their metabolic rate just plummets
so they go from as they lose weight
which they do in the short term their
metabolic rate also drops
and because their metabolic rate drops
they’re feeling
more tired and cold more hungry
and the worst part is that because
they’re burning less calories
even as they’re eating less calories
their weight loss slows eventually
plateaus
so now your weight is not dropping but
you’re burning 1200 calories instead of
two thousand so
your liver doesn’t get enough uh energy
or your heart gets less energy you’re
you’re not um you’re not generating body
heat you
feel really crappy and your weight is
still down so
as you relax that you start eating say
1400 calories
yeah but you’re only burning 1200 so
that weight comes right back so you see
on that
on that six-year study that some people
wound up like 50 pounds heavier than
I think it’s about controlling insulin
not about controlling calories so you
can do it many different
ways there’s uh paleo diets and so on
intermittent fasting just happens to be
one of the
better studied ways to maintain
your basal metabolic rate so we know
from our studies from
physiology studies that this is what
happens so why don’t we
use our knowledge to to
tweak it i mean i don’t say that
everybody needs to fast or should fast
it’s not easy it’s not
fun but why don’t we let people
use it as an option it’s it’s if you
don’t eat you’re gonna lose weight
that’s not that hard to understand what
you have to understand
too is that this is completely natural
and as physicians
physique when i talk to physicians
physicians always understand this point
because i say to them well we tell
people that they should never
ever miss a meal if you miss a meal
you’re gonna die
but we tell people to miss meals all the
time
when they have surgery you have to fast
when you do a colonoscopy you have to
fast
when you do fasting blood work you have
to fast when you do an ultrasound you
have to fast so there’s all these
situations
where we actually tell people too fast
and guess what nothing bad happens
everybody’s normal they might be hungry
they may be a little cranky but that’s
about it
nothing bad happens so why can’t we
simply use that as a therapeutic tool
to make people lose weight because these
people have type 2 diabetes they’re
obese they’re
having heart attacks they’re having
strokes this is a serious problem to
leave them at that level
the standard advice to eat less and move
more doesn’t work we all know it and the
studies all show
that it doesn’t work so why shouldn’t we
use this
tool that we have which is honestly the
most powerful weight loss tool because
you cannot go lower than zero calories
you can’t get
negative calories yeah so therefore this
is the most powerful tool
and we’ve decided to not use it like are
you kidding
me that’s got to be the craziest thing
i’ve ever heard everybody assumes that
you can’t do it because hunger will just
build and build and build and then it’ll
be intolerable
but that’s not actually what happened so
you can look at
the so-called hunger hormone ghrelin and
if you take somebody and you fast them
you can measure their ghrelin levels and
see what happens
so they’re in normal people you get this
three sort of spikes at breakfast lunch
and dinner so clearly there’s some
element of learning involved because we
expect to eat it’s 12 o’clock we expect
to eat so
our body kind of preempts us and expects
it and
puts out ghrelin but what happens when
you don’t eat when you skip that meal
is that the ghrelin does not continue to
go up it just falls back towards
baseline
so that’s really interesting because
again when i speak to physicians
they all know this because we all during
a residency medical student days we
miss meals all the time we’re just way
too busy
and you don’t have 45 minutes to sit
down at the cafeteria so you skip lunch
and that’s it so you’re a bit hungry
during that hour
and then once it’s faded so at 12
o’clock to 1 o’clock you’re a little bit
hungry
but you’re so busy you just keep working
by two or three o’clock you’ve forgotten
that you didn’t eat
and then sometimes you go huh i wonder
if i ate today and you didn’t
because the ghrelin has gone completely
back to baseline
so over the day these hunger actually
comes in waves and when people know that
they can plan for that so i say well
you know it’s going to come prepare for
it keep yourself busy
have some tea have some coffee drink
something
and let that wave just ride over you let
it pass and then by two or three it’s
done
and basically what you’ve done is you’ve
let your body
eat lunch or dinner or whatever of your
own body fat
and that’s perfect that’s exactly what
we wanted to do
and when you look at multiple days of
fasting it’s even more interesting
because
after about day one day two the hunger
actually the ghrelin which is
the hunger hormone peaks and then starts
to go
down so this is exactly what we see in
our clinic so when we have people doing
longer fast five days seven days 14 days
everybody says wow how can you do that
and the secret is that after day two
the hunger slowly fades on day two
you’re like wow i will never get
through this seven day fast on day five
you’re like oh i can go on forever
the hunger has completely disappeared it
is because now your body
is just feeding you body fat constantly
the levels of body fat
the fatty acid levels are high so your
body’s like why do i need to eat i have
tons of fuel here
because you’ve shifted fuel sources so
again people always get the wrong idea
they think it’s a one compartment
problem where all the calories
goes in one box and all comes out of one
box it’s a two compartment problem
there’s the food
and there’s a stored food and what
you’ve done is you’ve shifted your
your your fuel to come out of the body
fat
and now there’s just so much of it that
and it’s interesting because my
day five day six and not everybody but
some people go wow
i cannot believe how good i feel it’s
like their energy level is way up
because of the
adrenaline, the sympathetic nervous
system. I have no hunger at all
and a lot of people also note this sort
of mental clarity
which has been remarked over and over
again how they they think that they’re
much sharper more clear
and it’s like wow i feel amazing it’s
like well you know not everybody’s going
to be like that but if people
have this natural physiologic
response and they do well why don’t we
let them do it
and then they’ll lose weight because if
you don’t eat for seven days you will
lose weight
one other thing that’s that i would warn
people about though is
with about weight loss is that there’s a
lot of water loss
this is what people will tell you the
amount of weight loss the amount of fat
loss
on a fasting is only average as
half a pound of fat per day because a
pound of fat is roughly 3 500 calories
so if you’re eating normally 1800 2 000
calories
it’ll take two days to burn one pound of
fat
so on a seven day fast which sounds
really extreme
you can expect to lose three and a half
pounds of fat
that’s it so if you have a hundred
pounds to lose and you say wow i’m
expecting the seven day fast to do a lot
you will
you know you have a hundred pounds to
lose and you lost three and a half
that’s it
you will lose more because the rest of
that is water so you’ll probably lose
seven pounds 10 pounds even but if you
lose 10 pounds
six and a half of that will come back so
that you’re only three and a half down
at the end of the seven days
and that’s where people say oh you
failed because look you lost all that
weight but seven pounds came back well
you should have expected that that seven
pounds
was going to come back so you should
never have expected that loss of
water as it comes back it’s not a
failure it’s basically to what to expect
and
having having the experience when people
understand this and expect it then they
don’t feel so bad when
this weight starts to go back up because
you know that that’s what’s supposed to
happen
i’ve never done a very extended fast
because it simply doesn’t fit into my
schedule
very easily i have dinner with my family
most of the time so i do a lot of
shorter fast the 24 hour fast i have
done a few
i’ll tell you the reason i did them was
that i went on a cruise i gained a lot
of weight
because i wasn’t watching what i was
eating and i made a decision that i
wasn’t gonna watch what i eat so i ate
all kinds of crap like
ice cream and desserts and all that and
everybody knows so i gained a ton of
weight my rings weren’t fitting and it’s
not like okay this is not good
so then i went on a kind of longer fast
about i think
is about three days and i’ll tell you at
the end of the
it did three days then i went kind of
alternate daily fast and by the the the
next week
my weight was down to where it normally
was but i had a great time for that week
I
ate a lot of food that i don’t normally
eat and i think that
was probably the longest i did because i
was starting to get a little worried
with you know when the rings weren’t
fitting and my pants weren’t fitting
properly and so on
it was all the carbohydrates right i’m
not used to that high a carbohydrate
intake but
again that’s that’s as long as i’m gone
how long you have to go is unknown so
there isn’t
very much research into it if you talk
to some of the people who
have done these longer ones they’ll
often say
five days seven days i’m not sure i i
really don’t know
you can get a lot of the autophagy
cellular kind of what you want to do is
get into that kind of 24 36 hours where
you’re breaking down
protein because that’s where you’re kind
of getting that renewal cycle
pro the breakdown of the protein and
then the regrowth
you can get a lot of those benefits by
24,36 hours so i tend to do quite a few
of those
almost every day i come in and i see
somebody who’s completely off of their
diabetic medications and so on
one of the reasons we push some of the
longer fasts is that
these people are very sick that is we
can do this in a controlled manner that
is i can monitor them
as a doctor we have blood work we have
somebody that they can call
if they have problems we tell them to
stop so it’s a controlled situation
but the thing is that these are very
very high risk people
if you don’t do anything they will
develop a lot of different diseases
heart attacks strokes kidney disease eye
disease amputations all kinds of things
so
the rewards are much higher so we will
push the envelope a little bit more for
these
patients now you can also do very well
with shorter
intermittent fasting but it takes longer
it’s simply not as powerful as doing an
extended fast
yeah but again i would warn people that
it is something that
you have to adjust the medications
because you can’t take the same
dose of insulin for example and not eat
your blood sugar will
plummet and you have to do it in a safe
manner which we
try to do but yes you have to understand
that type 2 diabetes which is
sort of very near and dear to my heart
because that’s
the majority of patients that i treat
are type 2 diabetes
and what we see is that when you put
people on very low carbohydrate diets
when you use intermittent fasting you
can actually reverse the disease because
their blood sugars will come down you’ll
take them off all their medications
and that’s completely opposite to the
message that comes out from
the american diabetes association most
doctors which is that oh hey
type 2 diabetes is chronic and
progressive you’ve got it
you got it for life buddy that’s the
message that comes out
but it’s not true because we all know
that
as you lose weight that diabetes goes
away so you have to be able to make them
lose weight but instead of that the
doctors such as
what i used to do instead of really
working hard
to make them lose weight so that their
disease gets better
we would simply pump them full of
medications and i was guilty of that as
much as anybody else
but i understood eventually that these
people were not getting healthier
they were getting heart attacks they’re
getting strokes or getting kidney
disease which is where i come in
and they weren’t getting better yeah now
i see their diabetes kind of melting
away
again it’s it’s it’s not everybody not
everybody’s going to
do well with a fasting diet we’re all
individuals some people do very well
with
low carb diets some people sort of wild
diet or paleo diets
you got gotta find out what works for
you but what i what
my main message is is that these are
options for people don’t take away those
options of fasting intermittent fasting
extended fasting
because some people will do extremely
well on those other peoples will
they’ll do terribly and they’ll hate it
and i say well if you if it’s
not working and you hate it don’t do it
do something else
but for those people who do very well
well hey this is beautiful
yeah refeeding syndrome is actually
something slightly different so
during extended fast what you can
sometimes happen and this was described
more
in sort of extreme
prisoners of war in world war ii for
example
when you start to eat insulin 10 goes up
but because you’re very malnourished at
the beginning
phosphorus levels in the blood actually
plummet
so there are all the phosphorus is going
back into the cell due to the high
insulin load of the food and it gets so
low that you can get heart arrhythmias
and people have died for example
so if you look at the risk factors for
refeeding syndrome
it’s sort of more extended fasting five
days and beyond but also a baseline
level of malnutrition that is people who
are
truly starving holocaust victims
uh prisoners of war that sort of thing
key is to
that people who are not in that sort of
malnourished state or at
fairly low risk of that so again these
are people who would be
for example six feet tall and 90 pounds
like they’re so skinny these prisoners
of war
yeah when you apply it to people on what
I
applied to they’re 200 200 300 pounds
the risk is very very low but you have
to be aware that that is a potential
risk and it’s out there
the key is to and from when they’ve
treated them in the past
as i said i’ve treated over a thousand
patients i’ve never seen it but then i’m
not treating 90 pound people i’m
treating
390 pound people so the risk is highly
different but
you want to break the fast very slowly
so that insulin doesn’t go up you want
to try to avoid refined grains and sugar
when you’re refeeding you want to go
with more things such as
proteins and so on stuff with phosphorus
so
meat and so on you want to take it
slowly so that it doesn’t just
shoot up and in terms of the uh
the phenomenon where people say their
stomach shrank
it’s hard to know what that is maybe
it’s the ghrelin which has gone down but
we’ve all done this where we’ve gone
through a sort of extended fast and go
oh i’m gonna eat a lot
and then you eat a lot and you have this
big stomach ache
and everybody’s gotten that and
everybody who does fascinates like
you’ve all gone that and quickly teaches
you
not to do it because your body is
actually saying no
you don’t need this i’ve been feeding on
my own fat slow down don’t take so much
because i don’t want to switch back so
quickly to all this stuff so it’s very
interesting because a lot of people will
notice like yeah i’m so hungry
after my 36 hour fast but then i eat a
little bit i’m completely when you look
at these people who do hunger strikes
and all this sort of stuff
everybody kind of says wow how can you
do that and again remember once you get
past day two
every day after that gets easier and
easier because you’re actually just
feeding yourself body fat
if you look at 382 days
half a pound per day half a pound of
body fat per day is
somewhere just less than 200 pounds 190
pounds which is approximately what he
lost so if you’re
looking to lose 180 pounds and
unfortunately there are people who need
to lose that much that’s
the magnitude of the sort of caloric
restriction that we’re talking about you
could go down to zero for that amount of
time
so it’s funny because that’s the world
record it was monitored by physicians
they wrote it up
and so on and it’s like from okay
people can survive for 382 days
and we won’t even let people go 24 hours
without eating
before somebody starts brow beating them
into
stuffing a muffin into their mouth it’s
hilarious it’s like
are you kidding me one other thing i
would just say in terms of
when you’re getting into it there is a
period of adaptation
where about two weeks three weeks when
you start fasting where there are lots
of issues that come up
it’s kind of like exercise if you have
never run in your life and then you ran
and then your muscles are
all sore you’d be like oh running’s the
stupidest thing i’ve ever done
but you have to give it time you have to
get your body used to it so your body’s
not used to the fasting it’s not used to
shifting over to fat oxidation
so it’s kind of rusty and it’s not
getting there so you may get this kind
of keto flu where you’re just
kind of you’re not you’re quite yourself
you get a bit of brain fog you get a bit
of this get a bit of that
and what you have to understand is that
that happens to a lot of people
and the key is just to kind of keep
doing it keep letting your body get used
to it
and then after about two weeks three
weeks four weeks you’ll find that it’s
like nothing at all yeah
then now for example i can fast 24 or 30
hours without noticing much at all
half the time when i’m really busy like
writing the book for example i’m like oh
i do tons and tons of fasting not
because i really want to lose weight but
because i just want that extra half an
hour
to do my work so then there’s all these
different benefits that come into play
when you’re fasting such as
having extra time and so on and that’s
terrific it’s such a good option for
people
it’s not a cure-all it’s not a you know
one of these miracle things but at the
same time you’ve got to realize it’s not
like the
latest and greatest fad
oldest dietary intervention in the book
there’s no intervention more like more
ancient
don’t eat for a while that’s what uh
that’s what dogs do
they get sick they stop eating.