Kind: captions
Language: en
foreign
[Music]
it's one of the largest organs in your
body you can't live without
yet many people desperately want to lose
their fat
but Fat's been given a bad rap I think
fat is being an evil substance
but that is life
fat is critical to our health it is
releasing a whole host of hormones
important for our bones for our brains
for our reproductive organs fat is
actually a very sophisticated endocrine
organ for millions of years people who
were able to hold on to their fat had a
selective advantage and all of a sudden
we've asked people to get rid of their
fat but our bodies never evolved to do
that
so what happens when we have too much
fat
diabetes cholesterol issues heart issues
it just sneaks up on you it's like
smoking cigarettes it kills you slowly
you don't feel the pain I was aware that
it's gaining weight but I didn't know
what to do about it I follow every
single thing my mom would say I'd
exercise for literally an hour daily do
we control our fat or does it control us
scientists are finding hormones and
genes that act on the brain to influence
our size and shape
and those biological processes are well
beyond willpower
implications are huge obesity is the
number one chronic disease that we're
dealing with how can science weigh in on
our weight problem
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starting to fall together signals coming
from the body the brain and the genes
it's very complex but that's exactly
what you would expect for a system which
is so critical to survival
the truth about fat
right now on Nova
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this is Hiroki
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weighing in at around 550 pounds he's
about to take on Yama a two-time winner
of the Sumo World Championship
Yama is the heaviest Japanese man in
history
overeating is part of his job
while an average man eats around 2500
calories a day
sumo wrestlers consume up to ten
thousand
every year you are in sumo
harder it is to take you down
[Applause]
for years doctors wondered why sumo
wrestlers who stay active rarely suffer
from conditions triggered by obesity
answers would come as new insights
radically changed our views of fat
[Music]
most of us think about that as our enemy
it's not it's our friend
we need our fat to store any extra
calories so that we can use them in the
future to keep our heart beating to keep
our brain working and what we've been
learning over the last 20 years is that
the fat cell isn't just simply a storage
organ it's a highly intelligent cell
talking to our brains
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so why did body fat evolve in humans
to understand the forces that shaped us
a team of scientists have come to
Tanzania
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they've set up camp near some of the
last hunter-gatherers on Earth called
bahatza
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the human lineage is 7 million years old
and for the last two million years of it
we've been hunting and Gathering that's
the key innovation of the human species
and the hadza are a modern population
but they keep their old traditions still
very much alive and so this landscape
and this lifestyle is a really good
window into our own past
e
for over a decade Herman Ponce and Brian
Wood have been studying the lifestyle
and diet of the Hudson people to see
what it might teach us about modern
diseases
the hots are great models in public
health they never get heart disease they
never get diabetes they're not obese or
overweight and the diseases that we're
most likely to die from in the US and
Europe are not an issue with Bahasa
if we look at the Hodges level of
physical activity it certainly is quite
High when you compare it to Western
sedentary societies they cover more land
per day in their travels they spend more
of their day moving around and we know
that high levels of physical activity
are certainly protective against major
sources of mortality
with no livestock or crops had some men
and women must forage every day
Ubers rich and carbohydrates and fiber
while other women collect fruit and
Baobab seeds
boys scramble up trees to find bees
nests and harvest their honey
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but the richest source of calories and
the hardest to acquire are the meat and
fat of animals
hunting is a risky Endeavor and that's
one of the biggest gambles that you have
to take in this foraging economy is you
have to get up in the morning and go
hunting knowing full well that the odds
are against you
hatsa Hunters like dofu use poisoned
arrows to shoot their prey
Chase can take hours
the engine and Gathering takes energy a
lot of it
and so two million years ago we started
burning more calories we get bigger
brains
but the catch is that that puts us at
risk of starving to death because if
we're burning our engines hotter and
faster then there's that risk that
you're going to run out of energy and so
we've evolved fat as the safety net
when a man has been lucky enough to kill
a large animal the first thing he
usually does is to pinch its skin and to
see how much fat is on it because that's
such a key motivator for their hunting
and there is no other species that
extracts fat as efficiently from the
landscape as we do
foreign
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glucose provides immediate fuel or can
be stored as glycogen in our muscles or
liver
as glycogen is depleted the body burns
fat which yields per pound twice as many
calories
and while humans can only store about a
day's worth of glycogen we have enough
body fat to survive for weeks
think of fat as our battery
one of the big misconceptions about
human evolution is that we evolve to be
healthy and the answer is not really
the only thing that natural selection
cares about is how many offspring you
have we survive and then produce their
own offspring so our bodies are
beautifully adapted exquisitely adapted
to take any excess energy and turn it
into fat not because it makes us healthy
because it helps our reproductive
success
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fat has long been revered
one of the earliest representations of
obesity is a statue carved by
hunter-gatherers
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scientists have speculated that this
voluptuous figure symbolized fertility
over the centuries we've had a wide
range of views of what the optimal body
shape and the optimal body fatness is
right from the reuben-esque period
through to the flappers of the 1920s in
the heroin Sheik of the 1980s so across
time our views of what is an attractive
amount of body fat is varied enormously
today as we have stigmatized obesity we
have demonized fat but the ability to be
able to store fuel so that you can get
away from your food supply for extended
periods of time allows you to engage in
complex behaviors and the development of
the complex cultures that humans have so
fat is a feat of evolution it freezes
from the tyranny of having to eat
continuously
fat cells called adipocytes look like
bulbous spheres beneath the microscope
inside are droplets of triglycerides
fats that our body can burn to release
vast amounts of energy
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fat cells can expand far beyond their
normal size to safely store our excess
energy
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so what would happen if you didn't have
any
Troy fryer has less than two percent
body fat
although he looks extremely fit it's the
lack of fat that makes his muscles stand
out
with no padding on his face his cheeks
look sunken and his eyes are deeply set
how far are you off that way
a little bit of fat on my body is behind
my eyeballs and on my liver so walking
around not having fat
it feels like constant needles are
poking through the bottom of your shoe
you know some of us stand up all day and
we're okay with it Troy's not because he
has no padding on his feet nothing in
between his knees there's no Comfort at
all
it's just unbelievable to watch him
struggle
Troy was born with a normal amount of
fat
but by age six he began rapidly losing
weight despite having a voracious
appetite
I would go through two or three loaves
of bread in one day making 10 sandwiches
at a time so I would keep eating and
eating and eating until it would hurt if
I didn't get that food I would get
really upset and really angry I would
rip doors off their hinges I actually
sent them in for a psych evaluation
thinking that there was something wrong
because he couldn't take the answer no
it's like he was starving
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by age nine Troy was clearly ill
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doctors were shocked to find that his
blood was full of fat and cholesterol
symptoms typical of obesity
it made no sense until Troy was
diagnosed with a genetic disease called
lipodystrophy
we always think about thinness as
something good but in generalized
lipodystrophy it's beyond thinness it's
actually absolute lack of fat Under the
Skin So the excess energy doesn't have a
place to go
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and that's why Troy was sick
with no fat tissue excess calories
collected in his liver enlarging and
inflaming it
point of the doctor saying there's
nothing else we could do for you Troy
turn to the doctor and said so how and
when am I going to die
salvation would come from the discovery
of a mouse that also couldn't stop
eating
but unlike Troy this mouse was fat not
thin
a genetic mutant from a breathing
experiment it was nicknamed OB for obese
this Mouse had a defect in a single Gene
and the impact of that Gene was a mouse
that weighed three times normal and had
five times as much fat and that over ate
voraciously and genetics is very
powerful because what it tells you is
that obesity has a biological basis
what that basis is required identifying
the gene
scientists began to hunt for the
mutation that made the mouse obese
combing through the 2.5 billion letters
of its genome
think of as an alphabet you spell out
letters of the genome there are four
letters a g t and c these spell out
indirectly proteins and a single
spelling error can lead to a defective
Gene
in 1994 after a decade of work Friedman
and his collaborators honed in on a gene
only found in fat cells
that was really the moment of a lifetime
I pulled out the film with some vague
hope that maybe this would reveal
something about the nature of the OB
Gene and I looked at it and in that
instant I knew that we had identified
the gene that makes a hormone and that
plays a very active role in regulating
appetite metabolism and probably other
biological systems
so if you injected that hormone into the
blood of an OB Mouse the mouse lost
weight it would completely cure the
mutation of a ob Mouse and over the
course of a few weeks depending on the
dose you give they'll look
indistinguishable from a normal Mouse
the hormone was named leptin from the
Greek word leptos meaning thin
its Discovery transformed our view of
fat and the biological forces
controlling appetite
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the OB Mouse cannot see itself in a
mirror and realize that it's hugely
obese it thinks it's starving to death
because this very critical hormone is
not being made by the body it's the idea
that a hormone produced by fat can
control what you think about food in a
very important way this is a very
radical notion
foreign
never suspected hormones might be
driving her hunger
I just thought I didn't have enough
willpower in me to control myself from
food no matter how much I'd eat I was
starving all the time
from infancy Sana was overweight
have parents thought she would soon lose
her baby fat
but she only grew heavier
exercise for an hour daily doing like
cake
by treadmill or just being as active as
I could but I didn't know what was going
on and I was getting scared and I would
pack on like 10 or 20 pounds in a month
Asana struggled with obesity she sought
help from Dr Lisa Neff
[Music]
okay come on in Sana go ahead and have a
seat
so this is uh what we call an indirect
calorimeter what it's going to do is
measure how many calories your body is
burning in a day let's breathe normally
Sana had tried all different kinds of
diets exercise programs medications for
weight loss and yet she had continued to
gain weight
so the very first test that I did was a
leptin level in her blood and it was
undetectable
so Sana has been fighting hunger her
whole life and it's because she's lacked
this critical hormone
[Music]
like the OB Mouse Sana has a mutated
leptin Gene found so far in just a few
dozen people
[Music]
a normal fat cell produces leptin which
travels to the brain and signals the
hypothalamus a region that determines
when and how much we eat
[Music]
high levels of leptin tell your brain
you have plenty of fat stored
but low levels or in sana's case no
leptin at all triggers an alarm to eat
first of all you get the hunger signal
but secondly you slow down your
metabolic rate and if you're left to
levels fall even further your body says
you're starving and you do all sorts of
things to preserve your life you slow
down your immune system you turn off
reproduction so that you can survive
this period of starvation so the signal
is coming from the body to this bit of
the brain called the hypothalamus are
really so powerful
Sana is now taking leptin and has lost
40 pounds in three months
after taking the leptin I've noticed a
huge change in my Hunger I can go four
to five hours without eating anything
and I'll be totally fine
when I think about the future now I'm
seeing clear skies everywhere my
confidence levels have soared
okay
and for those like Troy who can't make
leptin because they lack fat getting the
hormone would be life-saving
starvation was gone within three days of
him taking leptin we saved a lot of
money
that Troy went from eating what three
people would eat to eating what a normal
person would eat in a day
knowing that I was full I'm like wow
this is amazing
[Music]
hurt leptin can't cure Troy's disease
but by curbing his hunger it protects
his liver
leptin does not bring the fat back it
just helps to deal with fats absence
patients finally can take a deep breath
that they're full and they don't have to
worry about eating
discovery of leptin was so exciting and
the molecule entered into clinical
trials in human beings and we awaited
the results of those trials with great
anticipation because we thought at last
we have something that's going to cure
obesity in our patients that turned out
not to be the case
most obese people produce plenty of
Lipton a lot of it and in fact what we
found out is that giving more to people
who have plenty doesn't have much of an
effect
while leptin couldn't cure common
obesity it revealed that fat was not
just a reserve of calories but a complex
endocrine organ producing dozens of
hormones
and those hormones are important for our
bones for our brains for our
reproductive organs for our muscles
they're important for everything and
through these hormones fat can
communicate with our bodies that can
communicate with our brains
so fat has different roles in our body
at different times of Our Lives
especially at Birth when a human baby on
average has the highest percentage of
body fat of any species now humans
really are by far the fattest day
a typical human baby is about 15 body
fat a typical hunter-gatherer male is
about 10 to 15 body fat typical hundred
other female is 15 to 25 body fat that's
leagues Beyond any primates
not only are we fatter than other
primates we also have bigger brains
compared to its body size a human baby's
brain is massive
and that brain is consuming half of that
baby's calories roughly that's a lot of
energy right and the baby can't stop
feeding its brain the brain doesn't hold
on to energy it's a constant thirsty
demanding organ and fat ensures that we
always have energy available to paint
for this thirsty organ
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so when you see a fat pudgy baby that's
a healthy baby because fat is life right
if you don't have enough fat you are at
risk
as we get older fat plays a role again
because you need a sufficient amount of
fat to have enough estrogen fat produces
estrogen in fact girls have to gain on
average about 13 pounds or so before
they're able to initiate puberty
[Music]
model heartya Andresen never thought
much about fat in she confronted the
pressure to be thin
will you send me the picture the
photographer who discovered me said you
know you perfect you're beautiful the
way you are but if you get into the
modeling industry they are gonna tell
you to lose weight so my word of advice
to you is don't don't do it
but for many models like Robin Lawley
that advice was hard to heed
women who walked the runway had to wear
size 2 or smaller clothing
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it was that heroin Chic look at the time
so it would be girls of my height like
six foot in a size zero so you had to be
emaciated to get that look you literally
had to starve yourself and if you didn't
do what you were told you could be cut
so I've tried I lost a bunch of weight
maintained it all for two minutes and
then it all came back on again
heartier lost the weight an agency had
requested getting down to 100 pounds
but slowly she began to realize that
being thin was not necessarily healthy
Carol had really bad quality and my
fingernails were really brittle I would
get cracked lips and sores at the corner
of my mouth but
the point that made me realize that
maybe I was getting too thin was when I
started breaking my ribs
Google starvation and that's what
happens like you will lose your period
you will cause all kinds of diseases
that you never thought would come to you
when I was speaking to my doctor about
wanting to have a baby he actually
warned me not to be any thinner and even
though I was exercising a lot I was
obviously not healthy
if you don't have enough fat stores one
thing that has affected significantly is
that we develop issues with bone which
can then lead to osteoporosis so actual
brittle bones that have a high
susceptibility to breaking and so that's
something that people might not think
about as we're looking for this
Aesthetics of getting to that Twiggy
ideal body image
foreign
at the other end of the scale are sumo
wrestlers
[Applause]
given their massive size how do they
avoid diseases normally associated with
obesity
the answer lies and where they store
their fat
safely underneath their skin
instead of in the abdomen or chest
packed around internal organs
so if you do a scan of an active sumo
wrestler a CT scan or an MRI scan you'll
see all that fat but it's on the outside
it's on the buttocks and thighs on the
outside of the abdomen so even though
they have body fat they don't can
lot of fat in those deleterious places
such as the liver around the heart
around the pancreas and even around the
kidneys so they're metabolically healthy
and the key reason is that sumo
wrestlers exercise rigorously up to
seven hours a day
when we exercise
our fat releases a hormone called
adiponectin and adiponectin actually
helps guide fats in the blood into safe
deposits of fat so they'll guide it in
the subcutaneous fat right under the
skin
interestingly when Sumer wrestlers come
off of their exercise regime they get
metabolically unhealthy very quickly
[Applause]
to maintain a stable weight
the number of calories you eat needs to
match the number you burn
so many assume that losing weight is
simply a matter of eating less and
exercising more
scientists are discovering that it's not
so simple
so what is astonishing is the fact that
we ingest more than a million calories a
year and yet we don't oscillate between
supermodel and an opera Diva over the
whole period of a year we stay pretty
stable so I think the best way to think
about how weight is regulated is to
think of it as a set point right that is
that our body is defending a very
particular weight under a certain set of
circumstances and it's obviously not set
because the body weight can change what
is said is what is the minimum body
weight for that individual
you drop your body weight below this
threshold the body will begin to do
whatever it has to do to prevent your
dying of starvation
that few Americans grasp just how hard
the body fought against weight loss
until a reality TV show called The
Biggest Loser captivated audiences
one of the heaviest contestants on
Season eight was Danny Cahill
for Danny competing on the show was a
shot at Salvation
something he had longed for since
childhood
[Music]
when I was a kid I was like if you could
have one wish what would you wish for
and you know most people say a million
dollars you know or something I say I
wish I could be like that person that
eats the same as me
and seems to never gain weight
as a child Danny tended to be heavy
but by the time he was a father he
struggled with obesity
his doctor warned that unless he slimmed
down he might not live to see his kids
grow up
I was mortified at how big I'd gotten
and it seemed like it happened overnight
it just sneaks up on you you don't feel
the pain
so when you gain a half a pound and a
half a pound and a half a pound every
week well in a year that that's 30 40
pounds and in five years it's 150 pounds
Danny saw the Biggest Loser as a second
chance
cutting calories and exercising around
45 hours each week he hoped to shed a
pound a day
I went there with a purpose I went there
to lose the weight I went there to break
a record I went there to to write my
life and to get the weight that I've
been carrying around for years off of me
as the season progressed Danny pushed
harder cutting back to 800 calories a
day
seven months later when he stepped on
the scale for the final weigh-in he had
lost a staggering
239 pounds
[Music]
[Applause]
I was mentally exhausted I was
physically exhausted in fact looking
back at it I go out and I do that how
did we do that that is crazy
[Music]
Danny was determined to keep the weight
off at home
[Music]
he delayed returning to work so he could
exercise several hours a day
when his book tour ended he went back to
his job surveying land
moving less and feeling constantly
hungry the weight came back
[Music]
Danny regained over 100 pounds and he
was not alone
six years later NIH scientist Kevin Hull
found that 13 of the 14 contestants he
examined had regained much of their lost
weight
over even heavier
[Music]
when you make extreme changes to your
diet or physical activity patterns your
body responds very strongly both in
terms of slowing down the number of
calories that you're burning as well as
increasing your appetite and hunger and
those types of processes that are
biological are well beyond willpower
close the door
research has revealed that as dieters
lose fat leptin levels fall triggering
hunger
as Danny regained weight his leptin
levels should have rebounded what did
they
started out kind of more or less where
you'd expect for your Orlando body fat
but six years after the Biggest Loser
here's where you ended up and I was told
that that would tell your body that
you're starving and that you needed to
eat so how am I going to handle this
being hungry all the time and with my
hormone levels out of whack and is that
ever gonna correct itself
thyroid hormones also fell
and that's one reason as contestants
shed pounds their metabolic rate the
number of calories they burn while
resting dropped
what was the surprise was that six years
later their metabolic rate was still at
the same level despite regaining all
that body weight
you started off at zero basically and
compared to other contestants after
Danny's weight rebounded his metabolic
rate had fallen the furthest their
metabolism was about 800 calories a day
lower than what we would expect I was
shocked my body
burned 800 calories less than a normal
man that was the same height and weight
and I just want people to realize that
obese people aren't just lazy people
there are a whole lot of things at play
here and one of them is our biology
so the vast majority of humans fail in a
dime and from an evolutionary
perspective that makes sense because we
never evolved to lose weight as soon as
you go in a diet and that activates
what's called a starvation response to
help us hold on to energy
the brain remembers that set point the
brain is a powerful organ and the
hypothalamus is powerful and knowing
what our weight was and so the brain
wins
[Music]
there's another reason why it's hard to
voluntarily control your weight
it's obvious when looking at identical
twins that the size and shape of their
bodies and even their gestures are
remarkably similar
that's because they share one hundred
percent of their genes
but that's not true for fraternal twins
they can differ in gender and size
because they only share half of their
genes
so if you systematically compare
identical to non-identical twins what
you conclude is that obesity is as a
more genetic than any trait that's been
studied with the exception of height
these twin Studies have shown that the
heritability of obesity is around 40 to
70 percent
self-obesity is not just about the
environment not just about your
lifestyle be your genetics determine why
some people gain weight more easily than
others
foreign
[Music]
genes that influence obesity a global
Consortium is analyzing genomes at
centers like the broad Institute
over 1 000 genes have been identified
that may play a role in determining
weight
most are for common obesity and have
small effects
but not all
the data mapped to 23 chromosomes is
publicly available to scientists like
Ruth loose
as she homes in on a specific location
she can search for individual genes
[Music]
to date researchers have identified
eight different genes which can cause
severe early onset obesity
and most of these genes
the brain they control food intake they
control hunger so ciety reward basically
components that we can think of as
controlling willpower
foreign
variants that don't cause obesity but
may make carriers heavier
one impacts leptin signaling
if you carried that mutation then you
would weigh about 15 pounds more than
someone who does not and we see that one
in five thousand individuals in the
general population carries that mutation
[Music]
but while genes can increase your risk
for gaining weight they can also protect
you
one gene variant found in about six
percent of the population makes carriers
always feel full instead of hungry
now this variant doesn't make you fat it
predisposes to making you leaner so we
need to understand that there are people
who are very susceptible and people who
are very resistant that obese people are
not morally inferior they're
biologically different
obesity is defined by your body mass
index or BMI a calculation that divides
your weight by your height squared
a BMI above 25 is classified as
overweight and higher than 30 as obesity
in the 1980s obesity rates in the U.S
began Rising sharply reaching higher
than 39 in many states
[Music]
he by far is the greatest Public Health
Challenge of our time it is the number
one chronic disease that we're dealing
with here in the United States and it's
leading to at least a hundred different
disease entities that we know of so we
will never get ahead of diabetes we'll
never get ahead of cardiovascular
disease we'll never get ahead of cancer
unless we address the root cause and the
root cause is in many cases obesity
and it's not just a U.S epidemic
in just three decades obesity nearly
tripled worldwide
according to the World Health
Organization one problem might be a
decrease in physical activity causing us
to burn fewer calories
so is one solution to simply be more
active
[Music]
back in Tanzania Herman puntzer and
Brian Wood working with a team of
international scientists hope to find
out
[Music]
they're giving members of the Hudson
community GPS devices to measure how far
they travel each day
GPS the answer might shed light on why
the Hudson don't suffer from the chronic
diseases seen in the West
without antibiotics a vaccine sadly a
lot of kids don't make it to their 15th
birthday
but if you make it to 15 in the haja
population there's a great chance you
can load to be in your 60s even 70s and
80s and with a much healthier body than
we would often have in the West
GPS data reveals why
Hunters like dofu walk about nine miles
a day
while women foragers walk about five
that's more exercise than the average
American gets in a week
so people also burn more calories each
day
I had spent many months living with the
hots that I had gone with them during
the day of foraging come back to camp
and I felt so tired and exhausted I felt
of course the energy use that we would
be detecting would be much higher than
in Western populations
to find out volunteers like dofu drink a
special water with hydrogen and oxygen
molecules that can be traced
[Music]
over the next two weeks by tracking the
depletion of these molecules the
scientists can measure the number of
calories burned each day
so we come out here we collect all this
data you know putting urine samples on
liquid nitrogen shipping them to one of
the best labs in the country and as the
results came back I wasn't sure what I
was seeing at first
77. despite being more active Hudson men
only burn on average 2500 calories per
day and hot for women about 1900.
the same amount as an average man and
woman in the U.S
[Music]
it's a really counter-intuitive result
and it really surprised us somebody who
is sedentary working a desk job in the
U.S is burning the same number of
calories as a hot as a man or woman
who's so much more physically active and
that's even after you account for things
like body size body composition age
gender all of those factors
the research suggests that no matter
what our lifestyle is our body protects
Us by keeping the total calories burned
each day within a narrow range
foreign
[Music]
exercise alone won't make you thin
I think we've had today to tell us is
that we can change our lifestyles
however we want and more activity is
always better
but it's not going to burn more calories
because our bodies adjust to these more
active lifestyles
implications are huge if obesity is not
due to sedentary Lifestyles it must be
caused by eating too many calories
foreign
to Daniel Lieberman that became possible
as humans changed their environment
so in the last 10 000 years we've
transformed both how we get energy
actually and how we use energy and the
first big shift occurred with the
origins of Agriculture when we shifted
from Simply going out and getting food
out there in nature to Growing the food
ourselves
farming allowed humans to Grow
carbohydrate-rich Foods
like corn wheat and rice
[Music]
and then we invented machines
and industrialized how we grow food
we've increased the scale of calories
that we produce by orders of magnitude
and the result is for the first time in
millions of years we have more energy
than we know what to do with
and it's not just an excess of calories
scientists suspect that obesity may be
caused by the changing nature of the
foods we eat
more than 50 percent of calories in the
U.S are consumed in the form of ultra
processed foods
low in fiber but full of fat sugar and
salt
packed with calories they've been
labeled obesogenic
cause us to overeat
find out Nora volkov has been scanning
the brains of patients with and without
obesity
to me the most important aspect about
obesity is understanding that the food
itself has made changes in your brain
that are driving your inability to stop
eating
these changes begin as food activates
our brain's reward system releasing a
feel-good chemical called dopamine
through pleasure dopamine motivates us
to find and eat rewarding Foods
Imaging reveals that high fat sugary
foods can overwhelm the brain's reward
system flooding it with too much
dopamine
our bodies actually have evolved to try
to maintain an homeostatic State and
that means that if there's too much
stimulation with dopamine you start to
see that receptors that are sensitive to
dopamine are down regulated they
decrease
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volkov found that dopamine receptors
seen as red in the brains of control
subjects are reduced in people with
obesity
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as dopamine signaling goes down our
capacity to be able to inhibit desires
goes down
so I said I'm not going to eat the
chocolate or I'm not going to eat the
donut
I don't want to eat it
can I stop it and if those areas of the
brain are not functioning properly
no matter how much you want not to do
something
it's very difficult to carry through
and this explains why people will tell
you I did not want to eat the food I
knew I was going to gain the weight yet
I could not stop myself
the truth about fat is complicated
Evolution has designed powerful hormonal
and neural signals to ensure that we eat
and defend our weight
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I think what people really need to
understand about obesity is that it's
not your fault this is not a matter of
your willpower
this is a disease it's a chronic disease
it's a highly complex disease and there
are many causes of obesity
can obesity be prevented or treated
the experts say maybe using a long-term
approach focused on health
I don't want to put you on the next diet
implies that it's short-term I want to
put you on a lifestyle plan that you can
sustain for years
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while The Biggest Loser reveals why
diets fail contestants like Danny who
continue to exercise kept off 10 to 13
percent of their weight
and medically that's a success because
modest weight loss has huge health
benefits from lowering blood pressure to
preventing diabetes
there are also medications that signal
the brain to feel full and help people
lose 10 percent of their weight
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and if you want to lose 100 pounds or
more there's another option
one that Muriel Mina chose to avoid the
fate of her mother
I was three and I remember she was
talking on the phone
and she collapsed because she had a
heart attack
and then I just remember EMTs rushing in
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at age 44 Muriel's mom weighed 300
pounds and had died of heart disease
as an adolescent Muriel began struggling
with her weight just as her mother had
I was going to the doctors and having to
get my heart checked and I was like wait
this is weird like I'm 13 at a
cardiologist it was always in the back
of my mind oh this is what she passed
from
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by age 16 Muriel like nearly 5 million
American teenagers had obesity and
qualified for bariatric surgery which
bypasses or removes part of the stomach
bariatric surgery is the only way that
most people with severe obesity can not
just lose weight but most importantly
keep it off
so you've been doing great the first
thing I want to show you is 275 was your
highest weight your body mass index was
43. after surgery you went all the way
down to 172 pounds and a BMI of about
28. and that's really fantastic
originally we thought that bariatric
surgery worked by making the stomach
much smaller so that you couldn't need a
lot of food
we now know that the hormones that come
from the GI tract and go to the Brain
Change in the way that cause satiety
earlier sooner and with much less food
these signal changes between the gut and
brain help the body reset its set point
for years
that's interesting but hunger can return
because our weight is as regulated as
our blood pressure and heartbeat
the ability to control our weight is
distinctly outside our conscious control
people don't like to hear that we all
want to think that we're in control of
when we put the fork down but there are
lots of biological forces that are
controlling what weight it is that you
end up
that behaves differently on all of us it
has to do with our genetics it has to do
with our age our gender a whole host of
factors
everybody is very different
what matters is to be healthy not to be
perfect
today RTA Anderson is 20 pounds heavier
a mother and modeling on her own terms
I had to overcome this fear of gaining
weight and that really took some courage
for me
modeling has the possibility to show
people how a healthy body should look
like
the focus needs to be more on strength
and health rather than being a certain
size
and there's another Insight provided by
the Hudson and Hunters like dofu
but the hard to tell us is that diet and
exercise are two different tools with
two different jobs
you need to exercise to stay healthy and
age well but you need to watch your diet
if you want to watch your weight
it's not a coincidence that the Obesity
epidemic is spreading around the world
wherever modern Western post-industrial
Lifestyles show up obesity follows with
them but I don't think a solution is to
go back to the Stone Age I think the
solution is to learn from our
evolutionary history and get the best of
both worlds
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