A Matter of Taste: The Brain and Obesity | Kimberely Steele, M.D., Ph.D.

A Matter of Taste: The Brain and Obesity | Kimberely Steele, M.D., Ph.D.


Thank you so much for
having me today. I’m gonna start first
actually with a quote. Today’s kids may become the
first generation in the history of man to have the life
expectancy projected to be less than that of their parents. I always start with this
quote for several reasons. One, I’m a bariatric surgeon and I actually direct
the adolescent program. I didn’t think I would ever
be operating on young teens, until I sat around a table and
heard all of the stories of these young people who
struggled with diet and weight management and then had
such bad medical problems. Two, I’m a mom. I have a five and
a six-year-old son, and I don’t wanna see them have to
struggle when they’re older. And three, I’m gonna show you a video that
the media has done really well. I use it actually when I
introduce bariatric surgery to my patients. It talks about the public
health’s significance of obesity. And in it are several quotes. One, this one, and two others
which I’m gonna bring up again. Because those quotes
strike me very strongly as a bariatric surgeon and
as a researcher of the things my patients struggle with
on a daily basis. So here comes the video. We can play it, please. [MUSIC]>>I’m 5’10” and 242 pounds.>>I always say this is
the biggest I’m ever gonna be, and I said that 20 pounds ago.>>A third of
Americans are obese, another third is overweight.>>Obesity is the biggest threat
to the health, welfare, and future of this country.>>I’ve always been overweight.>>I’ve got diabetes.>>Sleep apnea.>>Heart disease.>>Everything’s hurting now.>>It’s a lot easier to
lose weight than it is to keep weight off.>>This is probably gonna be the
first generation of children who are gonna have a shorter life
expectancy than their parents.>>18% of our children
right now are obese.>>It’s not only health,
it’s about survival and well-being of
the United States as a nation.>>You don’t crave broccoli, and our generation has grown
up craving a Big Mac.>>I wanna think that there’s
something better for me.>>Unless we’re able to
control this epidemic, we’re gonna have an abundance
of chronic disease.>>All of us have to be part of
the solution to reduce obesity.>>The weight of the nation
is out of control, but we can fix that.>>If we don’t now take this
as a really urgent national priority, we are all gonna
pay a really serious price.>>Obesity will crash
the United States in oblivion. [MUSIC]>>This is actually a trailer
from a series, HBO series, called Weight of the Nation. And I encourage you to watch
it cuz it is really good. So what are the two quotes
that really struck me? One, it’s a lot easier to lose
weight than to keep it off. And the other you don’t
crave broccoli, and our generation has grown
up craving a Big Mac. And that’s what I’m gonna
talk to you about today, my research is all about. So we live about
portion distortion, I show this to my patients, too. So which one is
the right portion size? Which side is the right portion? And even that is probably
a little more than we all need. But in America now, it’s all
about more and more food. Quantity, right,
not so much quality. In 1957, a hamburger
truly was one ounce, and we were all satisfied with that. And nowadays, it’s quadruple and
triple burgers. I have a six-ounce burger
up there which triples the calories, but
it’s even bigger quantities now. Coca-Cola in 1894 truly
was six and a half ounces. We see those little
bottles around? And Bloomberg was right
about trying to get rid of the Big Gulp,
the sugar and that. So one thing I tell my patients,
actually, if sugar’s in the first three ingredients of
any food label that they read, don’t eat it. And I can’t tell you how many
of my patients will come back before surgery, and have
actually dropped weight just from cutting out their
sugary beverages. How about Starbucks
lovers out there? Okay, I’m gonna ask you. How many calories are in
a grande mocha frappucino? Okay, 420. Pretty good. How about that tiny little
toffee crunch bar that tastes so good? 430. And what about
the lemon pound cake? More. 500. Whoa. We don’t even realize that. They’re tasty, you’re right. Actually, the story
with this one was, my boss took that picture. He went to Starbucks. He bought the pound cake to take
the picture to put in a slide show, and he ate the pound
cake on his way home, and then looked at afterwards how
many calories it was, and didn’t go back for another one. All right. America’s meal, fast foods. And I found this
on the Internet, childhood obesity cause
healthy food just plain sucks. So, here are some actual facts. 30% of teenagers and 40% of adults eat fast
food on a daily basis. And fast food adds about 200
calories a day to your diet. And this one really strikes me,
about 50% of Americans consume 870 cans of soda a year. One individual, 870 cans. What are the strategies
to treat obesity? Well, you’ve heard a bunch
of them today, right. We have diet and
exercise, we’ve all done. Medications. Behavior modification. Combination diet, exercise,
behavior modification. Some novel things, Dr. Pasarica
talked about, the balloon. Dr. Weiss is gonna talk about
bariatric embolization. And I’m here to talk a little
bit about surgical management. Well, here’s the deal, and we talked about this
a little bit in the last group. Traditional weight-loss methods
have limited effectiveness and sustainability, that’s
the problem. And I can tell you, here as
a bariatric surgeon right now, in contrast, bariatric surgical
procedures produce a significant and durable weight loss in
the majority of patients. Here’s an example of a medical
weight loss group and what I’m explaining
about medical therapy. So, let’s see. There’s my red. [LAUGH] Okay, sorry about that. Okay, the patients here
are a group of low-calorie diet, behavior modification,
and combined. And you’ll see that they lose
a significant amount of weight, about 32 to about 40
pounds in 6 months. But as you watch over the years, they gained more weight and
even more, right? So it’s yo-yo dieting until
they’ve gained even more weight than what they started at. And I can show you from
bariatric surgery, so this a gastric bypass band
in duodenal switch patients. You watch that over one year,
they lose weight. This is in body mass index so they drop a significant
unit of body mass index. And over time, they sustain
their weight, okay, and they keep it off. Now that’s not in the majority,
not in all patients, and that’s where kind of my research
is gonna come in in a minute. But just to keep you informed about the procedures that
are most current today. We have the vertical
sleeve gastrectomy and the Roux-en-Y gastric bypass. The vertical sleeve gastrectomy, basically, is a restrictive
procedure, and I tell my patients to
think of it like this. Your stomach is like the size
of a watermelon when it’s filled with food. And what we do is we actually
remove three-quarters of your stomach and leave you with
a banana-shaped stomach, which can hold about 100,
125 CCs, so half a cup. So it acts to restrict or limit the amount of food that
anyone can eat at any one time. Does it decrease hunger? Well, some patients will say yes
because we are removing the top part of the stomach, which some
say that releases ghrelin. And ghrelin is a feel
hungry hormone. So if we get rid of that,
you do decrease some hunger. But in general, it decreases
the volume that you can eat. In contrast, the gastric bypass restricts
the amount that you can eat. Because literally,
we are reducing the size of the stomach to the size
of an egg, okay? So it holds about 30
CCs at any one time. This part of the stomach
never sees food again. It hangs out,
stays in your body, kind of shrinks a little bit,
but doesn’t see the food. And then,
we reroute your small bowel and bring a piece of the small
bowel up to that tiny pouch. And so, what we create is
restriction and malabsorption. Malabsorption meaning less
calories are absorbed, and this is how this
procedure works. So these are the two most common
procedures that we do today. But how does bariatric
surgery cause weight loss? Well right now,
not everyone that undergoes bariatric surgery
has good results. And as Dr. Pasarica mentioned,
it’s drastic. The gastric bypass is drastic. But why is it that some do so
great and others don’t? And I think that’s
what spurred me and motivated me to
become a researcher. While restriction and
malabsorption are effective, and one of the ways that may
help patients lose weight, there are other ways, and
they need to be explored. And so, bariatric surgical
patients serve an excellent model for us, because we
have them before surgery and we had them after surgery. So, they are used as
their own controls. And they’re very valuable in
the exploration of obesity. As a clinician,
I have really found that my bypass patients have come to
me and said that they do not wanna go near sugar and
fat immediately after surgery. But that doesn’t last forever. It may last six months for some, it might last up to
a year in others. But those old habits
start to creep back, and the question is why. I’ve also noticed
that vertical sleeve gastrectomy patients don’t have
that similar taste aversion as much as bypass patients. They have some, but
not as strongly. And so, that’s what led to,
again, my research, trying to figure out why is
that, what are the differences? Well, let me give you
a bit of background. So, the regulation of food has
two main control mechanisms. One is called
the homeostatic changes. That’s all the hormone
regulation. So, we talked about ghrelin. Ghrelin is a hunger hormone,
and leptin, a satiety hormone. And they’re affected and work in the hindbrain and
the hypothalamus. Then, the other system
is the hedonic system. It’s a big word, basically,
about food reward. And food reward has two parts. It has food liking, which is
the taste of food, and it has food reward, which is the food
craving or the anticipation. So the food wanting, which is
the anticipation of food or the craving for food. My first study was in 2010,
it’s a very small study. I was able to get some funding
from the Association of Women Surgeons, and we took
five patients, my patients, gastric bypass patients, and we
scanned them before surgery and after surgery using PET scan. PET scan has a special,
we had a radioligand, it was a medicine that we’re
able to give our patients, and that radioligand actually binds
to the dopamine receptor. Dopamine is a feel-good
neurotransmitter. And if you don’t have
enough dopamine, you do other activities or you
eat or other behaviors that make you feel better when you
don’t have enough dopamine. So I took my patients,
I scanned them before and after gastric bypass, and what we found was that there
was an inverse relationship. As patients lost weight,
as their BMI went down, their dopamine receptor availability,
their sensitivity, improved. And I’m able to show that. This was our patients. The blue circle represents our
patients before surgery, and you can see at a higher BMI. And after surgery,
six weeks after surgery, the red circle represents
the six weeks after. And what you see in four
of these patients is that the dopamine receptor, which is
this axis, actually improves. The sensitivity of
dopamine improves. Now interestingly, this patient, my one patient, the dopamine,
nothing happened to her. She had really poor weight-loss,
very poor weight-loss. And so that was, again, one
of my motivations to do more. Of course, in 2010,
I had two kids back-to-back and had not gotten back to
research until recently. But now, I’m doing
some really cool stuff. I have a grant through the NIH,
and it’s entitled The Neurobiological Alterations
Induced by Bariatric Surgery, Taste Response, and
the Relationship to Weight Loss. And the question I’m asking is
does bariatric surgery really alter a patient’s taste
preference and craving? And if so, is this one
of the mechanisms for weight loss in our patients? And the hypothesis is that
altered taste perception in bariatric patients leads
to a decreased liking and wanting of high-calorie foods, which in turn leads to improved
eating behaviors and habits and consequent upregulation of
those dopamine receptors. The objectives were one, how
does taste preferences change before and
after bariatric surgery? And we looked at them before
surgery, about two weeks out before surgery, then two weeks
after surgery, three months, six months, and
a year after surgery. And then, the next question
was how does the blood flow change in the brain? Using functional MRI, we’re able
to look at that in real time, giving patients these tastes and also giving them
visual food cues. And taken together, our aims were to assess the
neurobiological alterations in taste preference induced by
weight loss interventions. So it’s a pilot study, there are
three weight loss interventions. We’re gonna do 20 bypass
patients, 20 sleep patients, 20 weight management patients. And currently, I’ve studied
21 out of the 60 patients. What we’re doing is were giving
these patients 12 taste stimuli of varying concentrations
of sugar and fat. And then, we’re asking
them to let us know what their taste preference is before
surgery and after surgery. Here are the concentrations. We’re using skim milk,
milk half and half, and heavy cream, and then
different levels of sucrose. And then, this is what it looks like on
the day of their taste test. It’s blinded, so
I don’t know nor do the patients know,
other than the look of it. And they’re asked to
swirl it in their mouth. And then on a visual analog
scale, which looks like this, weighted by 0 to
100 on the scale, they’re asked to give their
preference for each of those 12.

One thought on “A Matter of Taste: The Brain and Obesity | Kimberely Steele, M.D., Ph.D.

  1. every body should know that theres a law of God obese parents must have obese babies , thats how it work ,read exodus 34 :7

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