Transcriber: Gianna Carroni
Reviewer: Denise RQ At this moment, the number of obese people in the world exceeds the number of people
who are starving. Obesity is really a huge problem. It is leading to diseases
like diabetes, heart disease, some forms of cancer, depression. And why is there an obesity epidemic? The reasons are simple. We just eat too much and we exercise too little. Simple as that, right? I mean, everybody knows it, duh! Well, wrong. There are so many other factors
affecting our weight. Today, I will discuss
these factors with you. The good news here is there are so many other solutions
to have a good weight in addition to healthy diet
and exercising. Let me start with telling you
the story of John; at least, I will call him John. John was a boy who grew up
in the Netherlands. He was born in a foreigners' family, and he seemed to be a normal baby. The only remarkable thing
was that he was always crying. He was always hungry, actually. Within five minutes after finishing
his bottle of milk, he was hungry again. And by the time he was eating solid food, he was eating night and day,
he was craving for food, always. And by the time he was three years old,
he was massively obese. At that point his mother put locks
on all the kitchen cupboards, but still, he was craving,
and he was looking in trash cans, and he was looking for
eating even frozen food. All these years, his mother sensed
there was something wrong with her boy, because her other child was thin. So she went to doctors, and she asked for advice. But they basically told her that she was
just feeding her boy too much, and she felt like being blamed
for being a bad mother. She got frustrated. And at some point, she get referred to
the Erasmus Medical Center in Rotterdam. And she saw there my colleague,
Erica van den Akker, who is a pediatrician; and she found that John had a genetic abnormality
in his hunger hormone system, the MC4 receptor defect. What that basically means is
he had never the feeling of satiety, he was never full. This diagnosis was really important
for John's mother, because they really suffered
from the stigma, because they were accused
of having a weak character. After that, school, social networks, they started to support
John and his mother, and actually for a while,
his weight stabilized. He's now a young adult, and I see him
as a doctor in my outpatient clinic. And he is still struggling with obesity. Currently, medical treatments are
under development for patients like John so I hope to being able to help him
in a medical way in the near future. You would think, "Well this is rare." That's true, only 2% of the obese people are carrying a genetic abnormality
as the MC4 receptor like John, but there are other genetic variants
that would make you much more hungry or decrease your metabolism. So, if you see someone
eating extremely much, maybe we should think twice
before judging. So, it can be in your genes, and the genes affect your hunger hormones, but did you realize that crash diets
also affect your hunger hormones? Very low-calorie diets can also influence
your hunger hormones and increase them. In the short term, crash diets work, they reduce your weight, but the problem is that then,
your hunger hormones will increase, and also your satiety hormones
will decrease. Satiety hormones are the hormones
that make you feel full. We always think it's stretch
on the stomach that you feel full, but that's only part
of the story, actually. It's your gut giving
a hormonal signal to the brain, telling it you are full, and then you stop eating. So when this signal is not adequately
being provided to the brain, you automatically eat more. So, basically, after a crash diet,
you are hungrier. And that's even so in the long term. It has been shown
even a year after a very low-calorie diet, still the hunger hormones are higher. So, what about a conscious choice of food or having a weak character? The biology is telling you to eat more. The weird thing is your basal metabolism is also being decreased by a crash diet. So basically, you are hungrier, but you burn not that much calories
as you used to do. That's the perfect prescription,
of course, to regain your weight, and that's what we call the yo-yo effect; we know how it works now. So, basically, crash dieting
is another risk factor for obesity. Food can also affect your hunger hormones, but also your fat. Let's do a small experiment here. Imagine a box in front of you. And in this box there are chocolates. There are white chocolates,
brown chocolates, they're shiny. You smell the chocolate right now. And imagine you are taking one. You are taking one
of the chocolates right now. And you take a crunchy bite. And now you start feeling... You taste the soft, sweet praline
and chocolate in your mouth, right now. (Laughter) You are making hunger hormones
right at this moment. (Laughter) Unless you just had dinner. But that means, when
we go out now, for food, and we see sweets, we are much more likely to choose
the chocolate or sweet foods, rather that an nice green salad
or what you know is much healthier to eat. So, this choice of food is not
that conscious as we think it is. Your biology is driven by your thinking. The food industry perfectly knows this: they use advertising
and all these visual stimuli to stimulate also your hunger hormones,
making us eat differently than we maybe think it's good for us. But you can also benefit from it. Actually, it is the solution
also for obesity, because we know that saying,
"Well, eat less," is not working; but what is effective
is changing your thoughts by cognitive behavior therapy programs. That's effective. I told you now about the biology
and hunger hormones. But there are other factors
in our environment which affect the amount of food we eat. For example, our social
cultural background. We know that in some cultures
eating and food is hospitality. So, imagine that your neighbor has stood
in the kitchen for three days, cooking a delicious meal for you, and invites you over. Well, it is socially not really acceptable
not to eat all of it, and just take a tiny bit. So also your cultural background may
determine the amount of food you eat. Things have changed in the last decade. In the past decade,
we became much more stressed. If you are stressed, we know
your body is producing more stress hormones than usual. In particular,
the stress hormone cortisol, if you are stressed for
a prolonged period of time. We know that if you have
high levels of stress hormone, that makes you fat. Abdominal fat mass will increase. But that will also increase your appetite. In particular, your appetite
for calorie-rich foods. So, that's maybe why we grab a candy bar
when we are stressed. We don't know exactly
what's causing what, actually, because this sugar rich food seem
also to stimulate our stress hormones. So we found - our team and also others
found that obese people have higher levels of this stress hormone. So maybe when you're obese,
you get into a vicious circle of having elevated stress hormone cortisol
stimulating the calorie-rich food, and that in its turn, stimulates
again your stress hormones. So, psychological stress
can stimulate your cortisol, but also specific foods, and in particular,
also drinks like alcohol. We know alcohol's inducing
an increase of your stress hormones, increasing your abdominal fat mass. But there's more which is affecting
your stress hormones, and that's sleep. In the past decades,
with increase of obesity, we also reduced the number
of hours we sleep. The lack of sleep is also activating
our stress system, increasing our cortisol, but also
deregulating other appetite hormones. So the net effect of a reduced
number of hours of sleep is weight gain leading to obesity. So, the solution here for obesity
- additional solutions - may be to reduce your stress level and also to improve your sleep hours. And there's more. In this world, nowadays,
we take a lot of medication. I will tell you the story of Mary. Mary was a 20-year-old young woman who came to my outpatient clinic,
because she gained weight. She gained actually a lot of weight,
20 pounds within ten weeks, and she did not understand why. She entered my room, sit down,
and she started crying. Because she was eating very healthy, and she was exercising every day. And the reason she was so sad was actually because she was
a life-style coach herself. She was actually telling people how to eat healthy, how to exercise well; and now she felt that her clients
didn't trust her anymore as being a good life-style coach,
because she was gaining weight herself. And after some testing - she had received corticosteroid
injections in her knee - she had a knee problem
because she was exercising very actively. We know that corticosteroids
are an artificial version of your stress hormones. And remember, your stress hormones
increase your abdominal fat. And may also increase your appetite. So, she suffered from a really extreme
side-effect of medication. And actually this is rare. I see only a few patients
like this a year. But on the other hand, we use a lot of medication; some of the medication have
as a side-effect also weight gain, maybe in a more subtle way
than in this case. But still, particularly,
obese people use more medication. So, if you are obese,
and you want to lose weight and you are just about to enter
a treatment program for your obesity, and you use medication, it may be worthwhile
to discuss with your doctor whether that medication indeed
have weight gaining side-effects. And then to discuss whether
the dose can be reduced or the medication can maybe even stopped to make your treatment
much more effective. The last topic in our environment
I will discuss is brown fat. Who of you ever heard of brown fat? Please, raise your hand. Well, some of you, but most of you not. So well, actually, brown fat
is the good fat. We all know the white fat, that's
what's on your hips, and your belly, and that's unhealthy fat,
which is making you sick. But the good fat literally converts
calories into heat. It burns your calories. Well, that's fantastic! That's the Holy Grail! We all know these people
who can eat a lot, and they never gain weight. They have a good chance
of having a lot of brown fat there. In the past, we actually thought
that only babies had it, and we would lose it in adulthood. But it has been discovered
a couple of years ago that as adults, we also have brown fat. It's color brown because
the little energy factories in the cells color the cells brown;
therefore, it's called brown fat. And it's located around the neck,
the spine, between the shoulder blades, and around your kidneys. But obese people
have less of this brown fat. So they, basically, cannot burn
that much calories as slim people do. But there is good news, because it has been shown
that also people with obesity can actually stimulate
their brown fat tissue. You can do it either by exercise, which is hard if you are really
massively obese, but you can also do it by cold; by cold temperature. You don't need to worry, you don't have
to sit in a freezer for a day. (Laughter) But actually already is enough
- it has been shown - that if you spend for a couple of weeks,
for six weeks for example, two hours a day at 17°C, which is 62°F, just below room temperature, then you already activate your brown fat, and you will lose some kilograms
of your white adipose tissue. So you lose the bad fat. So, maybe in the past decades, we were spending
too much time in the heat, and we have not enough cold exposure - maybe due to our convenient winter
clothing and our well insulated houses, and driving around in well heated cars. Maybe we should just go out more often
and take our coats off, and tell our kids to play outside
without their jackets. Looking at all these factors: stress, and sleep, and medication,
and thoughts, and crash dieting - I think the problem of obesity,
and of the obesity epidemic, is that we think too simply. The solution here is look
at all these factors and change them where possible. It is now time to not longer judge
people with obesity but to start supporting them. And that's the way we will combat obesity
much more effectively. Thank you. (Applause)
