Latest / The Smart Cookies podcast / Staying Healthy In The Age Of The Obesity Epidemic. With Dr. Stephan Guyenet

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Staying Healthy In The Age Of The Obesity Epidemic. With Dr. Stephan Guyenet · The Smart Cookies podcast

0:00
And it's a struggle that most people are not
0:03
going to win. So if you're having to fight, literally
0:06
fight yourself every day, if you're having to
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fight these systems, these really survival systems,
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right, in our brains, these are systems that
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were forged in the distant past to keep our ancestors
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alive and reproducing. You're fighting systems
0:25
that are not really designed to be overridden.
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They're designed to be in charge and to not let
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you just, you know, make stupid decisions with
0:35
your conscious, rational brain, like not eating
0:39
enough as perceived by these systems. And so
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if you're fighting those systems every day, you're
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probably going to lose in the long run. Dr. Stephan
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Guyenet is a neuroscientist, obesity researcher,
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and author of the outstanding book, The Hungry
0:55
Brain, Outsmarting the Instincts. that make us
0:58
overeat. Dr. Guyenet, welcome to the show. Thanks
1:02
for having me on, Zaza. As part of my detailed
1:05
and extremely rigorous research for this interview,
1:08
I decided to clinically observe myself when I
1:10
go to the nearest 7 -Eleven, which fortunately
1:13
or unfortunately sits just outside my house.
1:17
And it was to my great shame that even though
1:20
I said to myself that I'm going there just to
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get some barley tea, I immediately found myself
1:25
over by the desserts fridge. where I kind of
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already knew that a particular type of chocolate
1:31
roll cake will be waiting for me. And it was.
1:35
And carrying on with the grand experiment, I
1:38
couldn't help but notice that my arm kind of
1:40
automatically grabbed the cake and paid for it.
1:44
And before I could really intervene, I was already
1:46
staring at the empty, greasy wrapper. And what
1:51
followed was what always follows, and that's
1:53
an encounter with an old friend called Guilt.
1:56
Since you're an expert in exactly this type of
2:00
behavior, do you mind telling me what happened
2:02
there? And most of all, why this keeps happening,
2:05
even though every single time I say to myself,
2:07
this was, in fact, the last time? Yeah, absolutely.
2:11
So I think this relates closely to the thesis
2:13
of my book, which is that there are different
2:17
brain regions that have different agendas that
2:20
are all kind of guiding our behavior. Essentially,
2:25
what you experienced there was a conflict between
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brain regions that wanted you to obtain certain
2:32
nutrients, certain calorie -dense nutrients like
2:35
fat and sugar, especially the combination of
2:39
those, versus brain regions that are more rational
2:43
and thoughtful and have goals for you like staying
2:48
lean, remaining in good health, eating a healthy
2:50
diet. See, if you didn't have the latter brain
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regions, then you wouldn't feel any guilt. You
2:58
would just be eating the food, right? So there's
3:01
a conflict there, an inner conflict that plays
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out between these ancient non -conscious or minimally
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conscious brain regions that determine our eating
3:13
drive and the conscious rational brain regions
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that have our higher level rational goals in
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mind for ourselves. two systems, it's really
3:24
more than two systems, but for now, we can think
3:26
about it as two systems are often in conflict.
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And that leads to a lot of struggle in our lives,
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it leads to a lot of not meeting the healthy
3:40
goals that we have for ourselves, such as you
3:43
experienced. And so in that particular case,
3:46
what you experienced was a behavior that has
3:53
been strongly reinforced so there is a lot of
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motivational drive behind that behavior you've
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engaged in that behavior previously received
4:04
a reward for that behavior dopamine was released
4:07
in your brain and now it's this kind of stamped
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in automatic complex of motivation and behavior
4:14
that gets triggered when you're in the environment
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that allows that behavior. So you've had this,
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you know, chocolate roll before, every time you
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have it, your brain, you know, your body senses
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the nutrients that are in that, that carbohydrate,
4:31
the sugar, the fat, the flavor, and it knows
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that on a basic kind of survival level, for our
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ancestors, when our brains were being shaped,
4:43
that that's a really important food for survival.
4:45
That's lots of calories. That's going to help
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you survive and reproduce in the environment
4:50
where our brains were being shaped. And so your
4:53
brain creates a very strong motivation. You get
4:55
dopamine release. And then that creates a sensitivity
5:00
to those cues that are associated with it. So
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next time you walk into the store and you're
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in the environment where your brain knows you
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can get that food and you see the food, that
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triggers the whole motivation and behavior to
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obtain that and consume it. And so it's this
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reinforcement loop would be the psychological
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way to to describe it. That really is, to a large
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extent, pretty automatic. I mean, I don't mean
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to say that we can't interrupt it. Like if somebody
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had put a gun to your head and said, don't eat,
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you know, don't eat this, you would be able to
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not eat it. Right. So it's not like it's not
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like we absolutely can't interrupt it, but it
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is. I would say effortful and often unreliable
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to try to disrupt those behaviors when we're
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in an enabling environment. From what you're
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saying, does it follow that our ancestors tried
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to eat one big heavy meal because they didn't
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know when the next meal is going to be coming
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from? My best understanding is that if we go
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back to hunter -gatherers, Our ancestors ate
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as much as possible whenever they could. And
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so it wasn't necessarily just one big meal per
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day. It was whenever they had access to food,
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they ate as much of it as they possibly could.
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And that's the impression that I got from speaking
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with anthropologists. For example, Kim Hill,
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who studied the Ache hunter -gatherers in South
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America, he told me that they would absolutely
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gorge on... things like oranges honey fatty meat
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and same for the hadza they in um in africa tanzania
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they that's another hunter -gatherer group that's
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been well studied by herman poncer and others
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and herman told me that they don't have any concept
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of restraint around eating food like the idea
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of gluttony that we have in western countries
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that's a modern concept that's not something
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that our ancestors had Or at least I shouldn't
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say that's not something that our ancestors had
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because that's a generalization. But I'll just
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say based on the anthropologists that I have
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spoken with, that's not a concept that I have
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encountered in hunter -gatherer populations.
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So their concept is not eating too much is bad.
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Their concept is eating as much as possible is
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good. And whenever you have the opportunity,
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because for them, obtaining food is difficult,
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effortful. and dangerous right and so it's not
7:44
like they're going to the grocery store and spending
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10 of their disposable income on food like an
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american would in in this incredibly abundant
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environment they have to go out and chase animals
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and climb trees and dig up tubers and do all
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kinds of other effortful dangerous uh difficult
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things to get their food and so and those things
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cost energy too And so you're always kind of
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fighting to get enough energy, to get enough
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nutrients to survive and reproduce. And so it
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makes sense that if you have an opportunity to
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eat a ton of calories, if it's right in front
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of you, right, you're going to eat as much as
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possible. That means you're not going to have
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to go out as much the next day and work hard
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and expose yourself to danger to get additional
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food. So that's kind of how our brains are wired.
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And I think that partially explains why we have
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a tendency to overeat. Our brains are wired to
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go for the food when it's available because that's
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what sustained our ancestors. The problem is
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it's just too easy to acquire. That's a problem,
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not the only problem, but it's very easy to acquire
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in the modern food environment. There's almost
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no effort barrier. Like even let's say, you know,
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the. You gave the example, what is it, a chocolate
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roll cake? Roll cake, yeah. Let's not mention
9:08
it anymore because I'm having difficulties with
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speaking. Yeah, that's what it was. But it could
9:14
be, I have a sweet tooth. Okay, so let's say
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instead of it was at the 7 -Eleven, you had to
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walk five miles and climb a tree to get that
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exact same food. I bet you wouldn't eat it as
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often, right? You would think about it pretty
9:30
hard if you had to do all that work. to get it.
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And you probably wouldn't do it as often. And
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so I think it's not just about the types of foods
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we're eating. It's about the food environment.
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What's the effort barrier that's there to eating.
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And in a hunter gatherer situation where we evolved,
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there were large effort barriers to eating. And
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so we had to have that strong motivational drive
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to get those calories to push us over those effort
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barriers. Today, we still have those drives,
10:00
but the effort barrier is almost gone. So when
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it comes to this type of compulsive eating or
10:07
whatever, are we dealing with the variant of
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the old adage that we have paleolithic emotions,
10:12
medieval institutions and godlike technology
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in a way only that we can substitute godlike
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technology with, like you said, an extreme abundance
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of very accessible calories? Yeah, I think that's
10:24
right. Probably the piece of that I'd most dispute
10:27
is the medieval institutions. I think most of
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our institutions are a lot better than medieval,
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but... Debatable, but... Yeah, that's outside
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of my area of expertise. So I'll put that one
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aside. Yeah, absolutely. So, I mean, our brains
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were shaped by food environments that are radically
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different than the current environment. And a
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lot of what our brains are doing is... underneath
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our conscious awareness. It's these hardwired,
10:59
evolutionarily shaped brain systems and brain
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functions that are very out of step with the
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modern food environment. So you think about where
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does hunger come from? We don't decide to generate
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hunger, right? There's not a conscious process
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where we're like, oh, it's noon. This is when
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I normally eat lunch. I'm going to turn on hunger
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so I can go eat. exactly the right amount of
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food, right? We don't decide when hunger is going
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to come. We don't decide how much hunger is going
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to come. We don't decide how much food it's going
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to take to satisfy that hunger. We don't decide
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what kind of cravings we have. These are all
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things that arise from non -conscious brain processes,
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right? And what's shaping these brain processes?
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These are hardwired brain systems. They're hardwired,
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but That doesn't mean they can't be influenced
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by the environment. I just want to say that.
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These are brain systems that evolved to operate
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and are calibrated for a specific environment.
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And that environment is no longer the one we're
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living in. And so, yeah, I think we do. I don't
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want to say that we, saying that we have paleolithic
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minds, I think is a little too narrow. I think
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our minds have been shaped by evolution. past
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the paleolithic period we're not exactly hunter
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-gatherers anymore most of us certainly are there
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has not been enough time in the industrial food
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system for our evolution to catch up to that
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so and then so that's that's that piece of it
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and then you said the godlike technology thing
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and yeah i think you know i'll you know godlike
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is a kind of uh you know a strong way to put
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it but I think we have become extremely good
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at satisfying our own food preferences. So we
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have these kind of innate food preferences that
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we're all born with, like an infant, a newborn
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likes the taste of sugar. You can put sugar on
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a newborn's tongue and they will have facial
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expressions of pleasure. And that's hardwired
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into rats. You can do the same thing to a rat
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pup and it will have facial expressions of pleasure.
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These are very deeply wired, evolutionarily conserved
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preferences. We like sugar. We like fat. We like
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starch. We like, to a certain extent, protein.
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We like those calorie -delivering macronutrients,
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calorie -delivering molecules that enhanced our
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survival and reproduction in ancient times and
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we like to get them as easily as possible we
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don't like to work hard for them and we like
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to get them in delightful combinations so not
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just you know a pile of plain sugar we like to
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have the flavors in it you know we like to have
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the fruity flavors and the chocolate flavors
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we like to have the fat and the sugar mixed together
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like in chocolate or chocolate roll cakes, sorry,
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and other foods like that, pizza, whatever it
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is. I mean, you think about almost any food that
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people really struggle to control their eating
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around. Typically, it's a combination of fat
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and carbohydrate because those two things, they're
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synergistic together in our brains. It's like,
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oh, it's not just one good thing. It's two good
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things together in the same food. And then you
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put the salt on it as well, which is also a motivating
14:42
factor. You put the, you know, fruity or chocolatey
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flavors or whatever. It comes together in a way
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that is extremely enticing for these hardwired
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motivational systems and can become hard to control
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in many people. And so, you know, coming back
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to the comment you made about godlike technology,
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you look at like a fruit, a piece of fresh fruit.
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that our ancestors would have had access to that
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is not a very calorie -dense food. It's mostly
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water, right? If you look at an apple or wild
15:19
berries, it's mostly water. It's got a lot of
15:22
fiber in it. It may not have exactly the flavor
15:25
you prefer. It might have a little bit of bitterness
15:27
or off flavors of some kind. But what did we
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learn how to do? Gradually, we learned how to
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say, hey, what is the thing in there we like?
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What's the thing in there that we really like?
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It's the sugar, right? How do we purify that
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even more? And how do we continue doing that
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until we have the absolute most purified version
15:47
of that possible pure granulated sugar? And then
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how do we take that and we mix it together with
15:54
the absolute most purified version of other dopamine
15:58
stimulating nutrients like fat? and salt and
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all those things so we're basically taking the
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active ingredient the active ingredient that
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triggers our motivation we're purifying it to
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the max where our ancestors could never have
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done that you know monosodium glutamate that's
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another great example and we're combining it
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in these combinations that just um are excessively
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motivating and so That's how we end up with these
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very strong reinforcement loops that end up with
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the types of behaviors that you observed in yourself.
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But even people who don't experience exactly
16:40
what you described, those things still tend to
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push us to eat too much. So maybe you'll have
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a little bit more on your plate. You'll consume
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a little bit more than you would have if it were
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totally unrefined, simple foods like our ancestors
16:55
used to eat. I noticed that I never or rarely
17:00
overeat on vegetables. Processed foods, such
17:04
as this unfortunate roll cake that's made in
17:07
some soulless factory, is another matter entirely.
17:13
Is that why processed foods are so bad for us?
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I think there are multiple reasons why processed
17:18
foods are bad for us, but I would say probably
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the number one reason is that we tend to overconsume
17:26
them. And by the way, the term processed foods
17:30
has been defined in many ways and people kind
17:32
of debate what the best way to define it and
17:36
what's really bad about it. And so I'm not going
17:38
to get into all that, but I'll just say that
17:40
I don't think processing per se is necessarily
17:44
harmful. I think it depends on how foods are
17:47
processed. So when the processing is removing
17:50
fiber, removing nutrients. making things more
17:53
calorie dense, making things more delicious.
17:57
I think that's when it tends to not be as healthy.
18:04
It tends to promote overeating. But, you know,
18:09
there are other forms of processing that are
18:11
probably harmless. Like if you're getting 100
18:13
% whole wheat bread, that is a processed food.
18:19
You know, and maybe there are even preservatives
18:21
in it. Maybe there are other ingredients in it
18:24
that you might not recognize. Probably most of
18:27
those are harmless, honestly. And you're probably
18:30
better off eating that than grandma's homemade
18:34
brownies from scratch because of the fact that
18:39
those brownies are more likely to lead to overeating
18:43
than the whole grain bread is. I'm dying to ask
18:48
you how I can trick the brain into performing
18:50
a big switcheroo with healthier foods, but let's
18:53
park this for now and I promise we'll come back
18:55
to it later on. We have to for my own sake. But
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since you're an obesity researcher, I wanted
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to ask you, why do we usually become obese? What
19:04
happens there? Yeah, so there are different ways
19:09
that we can look at it. One way is... The simple
19:14
way, the kind of physics way, which is that there
19:18
has to be a consistent excess of calorie intake
19:21
over calorie expenditure over a period of time.
19:25
So in other words, we have to eat more than our
19:27
body is burning for a period of time. When you
19:30
do that, your body accumulates fat. But there
19:34
is a larger question of why we do that. And I
19:40
think that question can also be addressed from
19:43
different angles. And one of them is that we
19:49
actually have regulatory systems for body fatness
19:52
and appetite in our bodies. It's not just something
19:55
that happens by accident passively. So if we
20:00
have these regulatory systems, why is it that
20:03
our body fat changes over time? Shouldn't a regulatory
20:07
system? keep body fat within a certain range
20:10
over time. And we don't really have a complete
20:16
answer to this question, but the body fat regulatory
20:19
systems seem to change over time. So people who
20:24
are initially regulating around a lean body,
20:30
so in other words, if they overeat a little too
20:34
much one day, they might undereat. The next day,
20:37
not doing it on purpose, it's just their regulatory
20:40
system is working. When they get to middle age,
20:44
maybe now they're heavier, they've gained some
20:47
weight, and their regulatory system is regulating
20:50
at that new weight. So if they, let's say this
20:54
person has developed obesity in middle age, if
20:58
they then try to lose weight to get back down
21:01
to where they were when they were, let's say,
21:04
20 years old. their regulatory system is actually
21:08
going to fight them. So it's going to be difficult
21:12
to lose that weight. And if they do get back
21:14
down to the weight where they were when they
21:16
were 20, it will be a lot harder to maintain
21:19
that loss than it was to maintain that weight
21:22
when they were 20 and their regulatory system
21:25
was in a different place. So you see this over
21:28
and over again in weight loss studies. People
21:32
lose weight. But then over the course of the
21:34
next year, they regain it. That's the typical
21:37
trajectory for someone who tries to lose weight
21:40
over using diet and lifestyle. It doesn't mean
21:44
diet and lifestyle is hopeless, but the effects
21:47
are definitely limited by pushback from this
21:50
regulatory system. Sorry to interrupt you, but
21:54
why is the baseline moving upwards as we age?
21:57
Is that necessarily always the case? No, it's
22:00
not necessarily always the case. and I'll give
22:03
you two reasons for that. One is that there are
22:05
individuals who it doesn't happen for. Probably
22:10
a lot of that is genetics. Some of it I'm sure
22:13
is diet and lifestyle, but there are also entire
22:17
cultures that that doesn't happen in. And there
22:21
aren't a lot of them anymore because the whole
22:23
world is industrializing. But if you look at
22:25
cultures, hunter gatherers or subsistence farmers
22:30
who are living in a, more ancestral human way,
22:34
many of those cultures don't gain fat at all
22:38
as they age. And you'll see as they transition
22:41
to an industrial diet, they will start to gain
22:44
fat as they age. But when they're eating a traditional
22:49
diet, body fat is essentially stable for their
22:53
entire lives. Is that because the diet has changed?
22:58
Because I presume that they still, you said they're
23:00
subsistence farmers, they're still working, they're
23:02
still physically active, right? Oh, so you're
23:05
asking how much of it is diet versus other things?
23:08
Exactly. Yeah. Yes. Versus activity or physical
23:12
activity, I mean. I feel fairly confident that
23:16
it's mostly diet. I think that physical activity
23:19
could be playing some role, but physical activity
23:22
is a less powerful lever over body fatness than
23:26
diet is. Diet is really the most powerful lever.
23:30
So I'm originally a rodent researcher. So we
23:33
were doing a lot of studies on obesity and rodents.
23:36
They're actually a pretty good model for human
23:38
obesity. They respond similarly to humans in
23:41
many ways to diet and to drugs and things like
23:45
that. And one of the nice things about rodents
23:48
is you can very tightly control conditions of
23:52
diet, of lifestyle, et cetera. And what I can
23:56
tell you... is that human junk food is extremely
24:02
fattening in rodents. The most fattening thing
24:06
you can do to a normal rodent that doesn't involve
24:09
surgery or drugs is feed a diet of calorie -dense,
24:14
highly palatable human foods. You give them a
24:17
variety of foods. You give them free, unlimited
24:21
access. You can even put their normal healthy
24:24
chow in the same cage. They'll completely ignore
24:26
it. They'll eat all of these chocolate rolls
24:31
and everything else. Big Macs. Yeah. Candy, sausages,
24:36
just whatever calorie dense, highly palatable
24:39
food you can think of. Cookies. They will absolutely
24:43
stuff their faces on it and they will rapidly
24:46
develop obesity. And there is nothing else you
24:50
can do. to a rodent a normal rodent that doesn't
24:56
involve surgery or drugs or thing you know unusual
25:00
things like that that will make them that fat
25:03
there's no you can even make pellets like pelleted
25:07
foods that are high in fat that are high in sugar
25:09
there is no macronutrient or combination of macronutrients
25:14
in a pellet that replicates that can fully replicate
25:19
the fattening effects of human junk food. It's
25:24
the entire package. It's the variety. It's the
25:28
combination of fat and carbohydrate. It's the
25:31
calorie density. It's the flavors. It's everything
25:34
all together is extremely fattening. It's not
25:38
just rodents either. I mean, you see like bears
25:41
that are eating through human trash, animals
25:44
that are fed by tourists, like they develop obesity.
25:47
Basically, any species, and this has been experimentally
25:51
tested also in a variety of species, pretty much
25:53
any species that is omnivorous and has the ability
25:56
to gain body fat, some animals don't, will develop
26:01
obesity on the current human diet. It's extremely
26:07
fattening across many different species. use
26:14
other levers like let's say now we're looking
26:17
at physical activity that can affect body fatness
26:20
too but the effect is much more limited so a
26:24
couple different ways to look at this if you
26:26
have mice and rats on a regular chow diet like
26:29
a healthy rodent diet and you don't let them
26:32
exercise they will gradually gain a little bit
26:35
of fat over the course of their lives as they
26:37
age they will get a bit fatter not to the point
26:40
of obesity but you know they'll get a little
26:44
pudgy um now if you have them exercise they will
26:48
not they will stay lean for their entire lives
26:51
now if you put them on an unhealthy diet an obesity
26:55
um promoting diet and you give them exercise
26:58
it will mitigate the fat gain so they won't gain
27:02
as much fat as they would have if they didn't
27:06
have the exercise but they'll still be much fatter
27:09
than an animal that is not receiving that fattening
27:13
diet so and you see the same thing in humans
27:16
like if you look at randomized controlled trials
27:19
so that i don't know how much your your audience
27:22
knows about study designs but this is a type
27:25
of rigorous study where you're putting people
27:28
you're randomizing people to different conditions
27:30
you're you have a control group it's considered
27:33
the gold standard of trying to understand how
27:36
one thing affects the other in biomedical science
27:39
so You can put people on different diets. You
27:42
can put people on different exercise regimes.
27:45
If you look across the literature, diet just
27:48
affects body fatness a lot more than exercise.
27:54
Exercise does affect body fatness. I'm not discounting
27:57
it completely, but it's just not as powerful
28:00
of a lever. And when the brain is trying to regulate
28:03
your body fatness up or down, appetite is the
28:06
main lever it's pulling. If I understand you
28:08
correctly, exercise is more relevant when it
28:11
comes to maintaining your weight than losing
28:15
it, right? I think that's right. I mean, I think
28:18
it's helpful for weight loss as well, but I do
28:21
think that it is more helpful for maintenance
28:23
than it is for loss. I also will say I think
28:27
exercise is very important for health and for
28:32
physical functioning as we age. So I don't mean
28:35
to say that exercise is not important. I think
28:38
it is important. I do a lot of it. But it's just
28:42
not the most powerful lever for body fatness
28:45
specifically. What role does genetics play in
28:49
us being more or less susceptible to weight gain?
28:52
Because we all have that one friend who eats
28:54
like a whale but goes to the toilet like eight
28:56
times a day and is just perpetually skinny. And
28:59
it's not fair. Yeah, it's powerful. Genetics
29:03
is powerful. And I think... Like you said, we
29:06
can really make common sense observations among
29:09
people that we see and come to that conclusion.
29:11
Right. So we all know people who just don't care
29:16
about diet at all and stay lean. And, you know,
29:19
maybe they're fit as well. They can run faster
29:24
than you, even though they don't take care of
29:25
themselves. I think we all know people like that.
29:29
And then there are other people who seem like
29:32
they're. obsessed with diet. They eat healthy
29:35
food and they are heavier. Maybe they even have
29:43
obesity. So yeah, genetics is huge. And if you
29:49
look at the studies that have actually measured
29:51
that, depending on the type of study, the range
29:55
of variation in body fatness between people,
30:00
that is explained by genetics is somewhere in
30:03
the 40 to 80 % range. So yeah. So in other words,
30:10
40 to 80 % of why one person is lean and another
30:15
person has obesity is thought to be due to genetics.
30:20
And there's debate about which number is more
30:23
accurate. But that's, I think it's somewhere
30:26
in that range. Yeah. So it's actually... a very
30:30
powerful factor and you know it runs in families
30:32
it's not just about it's not just about the diet
30:36
that people eat in families when kids get adopted
30:38
into different families their body fatness tends
30:41
to be more about who their parents were than
30:44
how their adoptive parent their adoptive family
30:48
lives and if you look at what is underlying those
30:54
genetics it's mostly about how the brain is constructed
30:58
and how the brain operates the genetics the specific
31:02
genes that vary that cause one person to be fatter
31:08
one person leaner mostly about how our brain
31:11
is put together well despite the different genetic
31:15
makeups that we have there is an obesity epidemic
31:17
especially in the west what do you think is going
31:22
on there I want to start by just expressing a
31:25
little bit of intellectual humility that we don't
31:29
know for sure. We can't run experiments where
31:33
we randomize different countries to different
31:35
treatments and rerun history a hundred times.
31:40
So the best we can do is look at the evidence
31:42
we have experimentally from human trials, from
31:46
animals, and then observational evidence from
31:48
what has changed over time in parallel with...
31:52
body fatness um that's interesting because before
31:56
you said that um you were telling me about these
31:59
communities of subsistence farmers and as soon
32:02
as their diets changed to our modern diets it
32:06
was easier for them to become obese so i was
32:09
i was thinking the answer is going to be very
32:10
simple well the answer is going to be diet okay
32:15
ultimately but i'm just i'm just uh i'm just
32:18
expressing uncertainty because right we don't
32:21
really know like i think there's you know i don't
32:24
think this is likely but i don't think it's impossible
32:26
that we learn that oh actually it wasn't really
32:30
the food it was some contaminant or it wasn't
32:34
really the food it was some microbe or an infection
32:37
something like that so there are other there
32:40
are other hypotheses i don't think they're as
32:43
well supported but i'm just trying to tell you
32:46
that this You know, what I'm going to say is
32:49
pieced together is my best guess from the available
32:51
evidence. It's not a rock solid home run. But,
32:55
you know, what I was telling you before that
32:57
food is the biggest lever over body fatness.
33:01
Well, our diets have changed radically over the
33:04
course of the obesity epidemic. And I think that
33:08
to me is by far the most likely suspect. If you
33:12
look at. yeah it's not just our diet what i the
33:16
term i typically use is our food environment
33:18
that's broader than just the foods that go into
33:21
our bodies it's about how those foods show up
33:25
in our environment how food cues show up in our
33:29
environment because you know if you go back just
33:32
in the united states 100 years our diet if you
33:36
just look at the foods we were eating it's probably
33:38
at least as bad as it was today maybe worse i
33:41
mean People were eating a ton of white flour
33:45
100 years ago in the United States, ton of white
33:48
flour. We weren't eating that much less sugar
33:51
than we are today. We're already eating a diet
33:54
pretty high in sugar. We're eating less meat.
33:56
We're eating less vegetables. We're eating less
33:59
fruit. And so the diet was very kind of refined
34:04
and monolithic. But. We were eating it in a different
34:11
context where everything was cooked at home.
34:15
I shouldn't say everything, but the vast majority
34:18
of food was cooked at home. There was not a huge
34:21
abundance and diversity of different kinds of
34:24
foods in the grocery store or in hardware store
34:27
checkout lines or everywhere at 7 -Eleven all
34:31
around us. And, you know, because foods had to
34:35
be prepared, we were eating them at mealtimes.
34:37
It's not like we had snacks laying on the counter
34:40
all the time. People were not often drinking
34:42
sugar sweetened beverages, caloric beverages
34:45
between meals. So even though the diet wasn't
34:49
necessarily healthy in terms of its composition,
34:54
the way our food environment operated. we were
34:57
not over consuming it as much. That's just to
35:00
illustrate that I don't think it's just about
35:02
the specific foods that we're eating. But I do
35:05
think it is also about the foods that we're eating.
35:08
So it's partly about the environment that we're
35:10
in, that lowers the effort barrier to eating
35:12
that puts foods and food cues around us constantly.
35:16
And it's partly about the fact that the foods
35:18
that we're eating are on average, more seductive,
35:21
more calorie dense. And probably easier to consume
35:26
like not as much chewing not as much you know
35:31
than they were originally so basically i think
35:35
all of those things coming together over time
35:37
is is the main reason for the obesity epidemic
35:41
it doesn't make sense i used to spend a lot of
35:44
time in france and you know there's a bakery
35:47
on every corner and it's just white white flour
35:51
and butter croissants and like baguettes are
35:54
flying off the shelf the shelves like it's nobody's
35:57
business and yet french people seem really fit
36:00
on average um so it it kind of confirms what
36:04
you were saying but i want to ask another question
36:07
i live in japan actually and contrary to popular
36:10
belief if you don't live in like rural okinawa
36:13
or something don't actually eat all that healthy
36:16
like fried foods are everywhere so are sweets
36:18
so is fast food so is 7 -eleven like i told you
36:20
so is alcohol However, the people, again, are
36:24
very lean. It's really hard, even in Tokyo, to
36:27
spot an obese person. And even when you do, it's
36:29
usually a Western tourist. I'm not going to lie.
36:32
The one thing that is true, however, is that
36:34
the portions here are noticeably small everywhere.
36:38
When people eat at home, when they eat in a restaurant,
36:40
even in like a 7 -Eleven packaging of sweets,
36:42
it's going to be much smaller than in the West.
36:46
And then people tend to walk a lot, but we talked
36:48
about exercise already. Why do you think the
36:50
difference might be so dramatic then? Is it the
36:53
smaller portions or is it genetics? Yeah, so
36:58
I want to address the genetics question first.
37:01
I think it's mostly not genetics. And the reason
37:04
I say that is because there is a study that was
37:08
done of migrants from Japan to the United States
37:12
and what happens to their body weight and health.
37:15
And what they found is that migrants gained a
37:18
lot of weight when they migrated to the United
37:20
States, specifically Hawaii. So would they become
37:25
exactly as obese over time, over generations?
37:28
I can't answer that question, but certainly the
37:32
genetics does not protect them against gaining
37:37
a substantial amount of fat in the United States
37:39
when they immigrate. So I don't think genetics
37:43
is a great explanation for it. I think the food
37:47
environment makes a lot more sense. I think there
37:52
are, well, I'll start with the easy part and
37:55
then we'll get into the hard part. The easy part
37:58
is if you look at the diet in Japan, it is less
38:04
calorie dense, lower in fat, higher in carbohydrate
38:08
than the diet in... Hawaii. So I think when they
38:13
moved to the United States, the diet basically
38:15
got richer. I'm sure they were eating more calories
38:18
as well. So that's the easier piece. The harder
38:24
piece is kind of why that happened. And I think
38:30
that gets down to a question that is really hard
38:33
to study, which is culture, food culture. And
38:37
I think that Japan has a culture around eating
38:43
and meal times and portions that is different
38:46
than the American culture around those things.
38:50
It's really hard to study that. It's really hard
38:52
to quantify the causal impact of that on eating
38:57
behavior and body fatness. But I think when you
39:01
have data like the one that I explained about
39:03
the migrant study, it's hard to think of. You
39:08
know, it's it's hard to account for those observations
39:12
without placing at least some weight on food
39:15
culture as an explanation, I think. And I think
39:18
the same is true in France. I have strong connections
39:20
with France. My dad is French. And I see how
39:24
they eat. It's in most cases pretty different
39:29
than how we eat here in the United States, partially
39:32
in the types of foods that they're eating. But,
39:34
you know, the food, most of it is. cooked at
39:38
home. Uh, they're, they eat less processed foods.
39:42
They don't eat a lot between meals. So there's
39:46
not like snacks laying around that people can
39:48
just grab whenever they want. It's really common
39:50
in the United States actually for people to not
39:54
really even have meals like in, like in families,
39:58
not sitting down together for meals. There's
40:01
just food in the fridge. There's food in the,
40:03
in the pantry and people just grab it whenever.
40:07
They're hungry and there's a variety of different
40:08
things. So, you know, kids can have whatever
40:11
they prefer. And that's that's like that would
40:15
be inconceivable to most French families. I mean,
40:20
I'm sure things are changing over time, but like
40:23
the traditional French way of eating, that would
40:25
be like the absolute antithesis of it. You're
40:28
there's not food laying around. Everyone comes
40:30
together for meals. Most of the meals are made
40:33
are prepared from. Fresh ingredients. Yeah. Again,
40:38
it's hard to quantify. It's hard to make a really
40:40
hard argument for this. But I think just cross
40:46
-cultural comparison, to me, it's very likely
40:50
that food culture plays an important role in
40:55
the obesity epidemic. No, that totally makes
40:57
sense. Although probably even in Europe, it's
41:00
likely going to change with food that's delivered
41:03
through an app. While you're working at home.
41:06
And I think it is changing. Yeah, I think it
41:08
has changed over time. And I think that's reflected
41:11
in body fatness. And, you know, even in Europe,
41:15
their body fatness is going up, depending on
41:18
the country. UK is not that far behind the United
41:21
States. You know, so even within Europe, it varies
41:25
quite a bit. Yep. Last one on this matter, and
41:30
then I'll stop, I promise. What about booze?
41:33
If you take that away from me, I'll have next
41:35
to no consolations left. If I want to lose some
41:37
weight, like, do I have to give up alcohol at
41:42
all costs? I mean, you don't have, no, you don't
41:45
have to give up alcohol at all costs. But I think
41:47
alcohol is certainly a factor that makes weight
41:51
control more difficult, particularly depending
41:54
on the type of alcohol. So alcohol is inherently
41:58
high in calories. So I think one standard U .S.
42:04
drink, which would be like a beer or a glass
42:09
of wine or an ounce and a half of spirits. I
42:13
know I'm using American measures here. Apologies.
42:18
That the alcohol in that has, if I'm recalling
42:21
correctly, about 90 calories. But in a beer,
42:25
you don't just have the alcohol you have. additional
42:29
carbohydrate. And in a mixed drink where it's
42:33
sweet, for example, you would also have additional
42:35
carbohydrates. So I would say the first move
42:37
would be to drink lower calorie types of alcohol.
42:41
So wine or spirits, dry wine or spirits have
42:46
lower calorie per drink. But again, alcohol is
42:51
inherently pretty high in calories. And then,
42:54
I mean, really the big picture is If you're trying
42:58
to control your body fatness, it's not just about
43:03
individual foods. It's about the big picture.
43:06
How many calories are you consuming in total?
43:09
Because you could have a very healthy, high satiety,
43:17
lower calorie dense diet, and then you could
43:20
have a drink or two every day and still be losing
43:24
weight. So it really depends on the total dietary
43:28
context, not just individual things that you're
43:32
doing. So alcohol is going to tend to push weight
43:35
up because of its caloric value. But that doesn't
43:38
mean, you know, it's just one lever in the overall
43:41
picture. Are there any studies on psychological
43:45
states in the foods that we eat? Because again,
43:48
with myself, I'm going to notice that if I need
43:50
some soothing, I'm again going to go for the
43:53
worst thing possible. Is there any correlation
43:55
between, I don't know, trauma and overeating?
43:59
Yes, there are correlations between trauma and
44:04
body fatness and eating disorders. So people
44:08
who have early life trauma tend to have a higher
44:15
risk of developing excess body fatness and developing
44:19
eating disorders like binge eating and things
44:23
like that. Yeah, so I think there is a connection
44:26
there. And I also, you know, I want to be clear
44:30
that I don't think that explains all of it. So,
44:33
you know, I don't think you can see a person
44:36
with obesity and say, oh, they're, they have
44:39
excess fat, because they, you know, had some
44:42
traumatic thing when they were a kid, or they're
44:45
stressed or whatever. I think it's a factor that
44:47
can contribute. Yeah. And I think what you said
44:51
is basically correct that When we're stressed,
44:55
food can help soothe us. And there's been studies
44:59
on this where the brain systems that are activated
45:02
in stress, you can directly measure that the
45:05
activity in those regions go down when we get
45:08
comfort foods, which are typically these highly
45:13
rewarding calorie dense foods. Like when you
45:17
want to feel soothed, you're not usually going
45:20
to be eating celery and lentils, right? Yeah,
45:23
why is a cauliflower not soothing me? What's
45:26
up with that? Yeah, yeah. Why does it have to
45:29
be pancakes with Nutella, you know? Yeah, absolutely.
45:33
I think it's because pancakes with Nutella is
45:38
a lot more pleasurable to you. And so, you know,
45:42
the pleasure of that dampens those stress circuits
45:46
more. So I guess we finally come full circle
45:50
and you can tell me how to trick my prehistoric
45:53
brain so it's going to treat a zucchini the same
45:56
way it treats a slice of pepperoni pizza. Well,
46:00
I don't want to overpromise here. I don't think
46:02
I'm going to get anyone to enjoy a zucchini.
46:07
Anyway, but I think there are ways to work with
46:12
these systems better. I think, you know, we started
46:15
off this conversation talking about this conflict
46:17
that often occurs between these hardwired, non
46:21
-conscious brain systems that determine our motivation,
46:23
hunger, etc. Conflict of those systems versus
46:28
the conscious, rational brain regions that are
46:32
trying to manifest our higher level goals like
46:36
health and longevity and physical appearance,
46:40
etc. Looking good in a bathing suit. And there's
46:44
that conflict. And so that, you know, sets up
46:49
a very difficult struggle for many people. And
46:54
it's a struggle that most people are not going
46:57
to win. So if you're having to fight, literally
47:00
fight yourself every day, if you're having to
47:04
fight these systems, these really survival systems,
47:07
right, in our brains, these are systems that
47:09
were forged. in the distant past to keep our
47:13
ancestors alive and reproducing, you're fighting
47:18
systems that are not really designed to be overridden.
47:22
They're designed to be in charge and to not let
47:26
you just, you know, make stupid decisions with
47:29
your conscious, rational brain, like not eating
47:33
enough as perceived by these systems. If you're
47:37
fighting those systems every day, you're probably
47:39
going to lose in the long run. So my approach
47:43
is how do we get those systems to align? How
47:47
do we get those two systems to align so you're
47:50
not fighting yourself anymore? And to do that,
47:53
you have to know how to speak the language of
47:56
these systems. What do they want? What do they
47:59
respond to? There are a couple of different angles
48:02
we can look at this from, but one of them is
48:05
we can look at. the satiety system, which is
48:08
the system that determines how full we feel at
48:11
a individual meal. And so that system is trying
48:15
to make sure that you get enough food, but not
48:17
too much in a particular meal. And it turns out
48:22
that that system, how full it makes you feel
48:24
and when it tells you to stop eating at a meal,
48:27
depends a lot on what you're eating. So if you're
48:31
eating foods that are very calorie dense, in
48:34
other words, have a lot of calories per gram
48:37
of food. So those would be foods that don't have
48:40
much water, have a lot of fat, that don't have
48:43
a lot of fiber. Those kinds of foods are not
48:46
going to fill you up as much per calorie. So
48:50
each calorie that you eat, essentially you're
48:53
going to have to eat more calories to achieve
48:55
that feeling of fullness that tells you to stop
48:57
the meal. And that would be the, you know, kind
49:01
of foods that people intuitively recognize as
49:04
fattening, like pizza and cakes and cookies and
49:10
things like that, fried foods. So calorie density
49:16
is one thing. Low -protein foods are not as filling
49:22
per calorie. Low -fiber foods are not as filling
49:25
per calorie. Foods that are highly palatable,
49:28
so foods that are... you know, the ones that
49:31
we really, really love to eat, those are not
49:33
as filling per calorie. It's like your brain
49:37
shuts off satiety a little bit to get more of
49:40
this desired food. And so conversely, if we eat
49:45
foods that are lower in calorie density, higher
49:48
in protein, higher in fiber, these are things
49:51
that are more like what our distant ancestors
49:52
would have eaten, kind of fresh meats, fresh
49:55
fruits and vegetables, whole grains, eggs. those
50:00
types of foods without a lot of added fat, those
50:04
things tend to make us feel full with fewer calories.
50:08
So that way, you know, that way you're kind of
50:13
aligning the satiety system with your higher
50:16
level goals for yourself instead of the alternative
50:19
would be, you know, this I'm kind of caricaturing
50:22
this as an extreme example, but you. sit down
50:27
the way to generate maximum conflict would be
50:29
you sit down to a meal of let's say pizza and
50:33
ice cream and a and a soda and you say okay i'm
50:40
gonna sit down to this meal but i'm only gonna
50:42
eat uh i'm gonna do portion control i'm only
50:46
gonna eat half the amount of calories that i
50:49
would normally eat of this because i'm on a weight
50:51
loss diet that is going to be really difficult
50:54
Because your brain is going to be saying, I really
50:56
want to eat way more of this. And the other part
51:01
of your brain is going to be saying, no, I'm
51:03
on a diet. I don't want to eat this. That's the
51:06
conflict situation. So if you're giving your
51:09
satiety system foods that allow it to feel full
51:12
with fewer calories, then you're aligning those
51:14
two systems. So that's one way. Another way is
51:20
the system that... is by working with the system
51:23
that generates cravings and so this is the one
51:27
that brought you to that chocolate roll cake
51:29
right this is the reward system because you probably
51:32
weren't well i don't know i'm making assumptions
51:35
here but you probably weren't going for it because
51:37
you were feeling hungry right it wasn't like
51:39
your assumptions are completely correct yeah
51:42
okay i'm never hungry when i had it yeah okay
51:44
yeah so it's not like oh i really need some food
51:47
i'm so hungry i need to get this it's more like
51:49
this is a food that i really love and i feel
51:54
the motivation for so i'm going to go get it
51:56
even if i'm not hungry and so that's a different
51:59
brain system than the one that regulates hunger
52:02
and satiety and um that's the food reward system
52:06
and so for that one it's very driven by environmental
52:12
cues so if you're in that 7 -eleven where you
52:17
would normally buy that food that's a cue for
52:19
your brain that triggers the craving if you never
52:22
went into that 7 -eleven you're not gonna you're
52:26
probably not going to trigger that craving or
52:28
not as much and it will probably if you do have
52:31
a little bit of it probably be easy to inhibit
52:33
that behavior so really what um the best way
52:38
to address that system is to control your food
52:42
environment so you're controlling the cues that
52:45
you're giving your brain You're not giving it
52:47
the cues that stimulate that craving, which would
52:50
be anything associated with that food. So you're
52:54
not leaving it on the counter so you can see
52:56
it. You're not leaving it in places where it
52:59
would be very easy to access and your brain knows
53:02
that, like the counter is a good example. You're
53:06
not walking by places where you smell the fresh
53:10
baked bread, you know, the bakery or whatever.
53:16
limiting your exposure to food advertising that's
53:19
showing you pictures of you know the foods that
53:22
might stimulate your your craving you're not
53:24
going to the locations where you would typically
53:27
eat um a food that you don't want to eat it's
53:31
the same it's really the same playbook as quitting
53:34
smoking it's exactly the same playbook um living
53:38
in japan you know it's a very densely populated
53:41
country especially if you're in tokyo so i might
53:45
as well like lock myself in a buddhist monastery
53:47
it is certainly more difficult in some uh food
53:53
environments than others i acknowledge that it
53:56
can be difficult if there are families with kids
53:58
um which is the case for me i mean you you seem
54:03
to be in really good shape if you don't mind
54:05
me saying and what works best for you is it the
54:10
triggers removing the triggers or is it the satiety
54:13
I do all of it. Or is it both? I do all of it.
54:15
And I probably also have relatively favorable
54:20
genetics. I probably would have, if I didn't
54:23
care at all about nutrition or, you know, exercise
54:26
or whatever, I probably would have a little potbelly,
54:29
but I don't think I would have obesity. No one
54:33
in my family has real obesity. So I think there
54:37
is some favorable genetics. Just want to acknowledge
54:39
that. But also, yeah, no, I control food cues.
54:44
I don't have most of the time I don't have foods
54:48
that I that aren't consistent with my goals in
54:51
my house. There are some exceptions to that.
54:53
Having a kid in the house, I am not really able
54:56
to be as strict as I want to be with myself.
55:00
But I also tend to eat foods that have a high
55:05
satiety per calorie value. So like my breakfast,
55:08
for example, is. oatmeal cooked in water with
55:11
fat -free Greek yogurt and blueberries. And so
55:18
that's a lot of protein, a lot of fiber, low
55:22
calorie density, and it keeps me full for a long
55:24
time. I limit my snacks in between meals. And
55:31
then there's also exercise as well. I run and
55:34
I do weightlifting and lots of yard work and
55:37
stuff like that. Yeah, I try. I don't make it
55:40
easy for myself to eat food. Like mostly if I
55:42
want to eat, I have to cook something. There
55:47
are a few exceptions, but nothing that's very
55:52
tempting, like unsalted roasted nuts, for example.
55:57
I could get some of those if I wanted to in the
56:00
kitchen, but I'm not going to do that unless
56:02
I'm really hungry because it's just not that
56:04
tempting. Or a piece of fresh fruit. so um it
56:10
helps if they're covered in chocolate yeah that's
56:14
right so i do all of it yeah basically and i'm
56:17
not extreme about it i i eat a pretty moderate
56:20
diet um but right so you're not like that longevity
56:24
guy brian johnson who eats like one carrot stick
56:27
and 324 supplements a day yeah no um okay that
56:33
Yeah. Anyway, I won't comment on that, but that's
56:36
not what I do. And, and that works for me, but
56:41
I also, you know, if, if I had, if I actually
56:44
had obesity or I was more susceptible to it,
56:47
I might be stricter than I am. But yeah, I do,
56:51
I do a light to moderate version of all those
56:53
things that we discussed. And I think that. In
56:59
a country like the United States, the lifetime
57:01
prevalence of obesity is over 50%. That's probably
57:05
going to change with the GLP -1 drugs. But if
57:08
you don't do anything in the United States, chances
57:12
are you are going to gain fat and you're going
57:15
to become unhealthy if you're just going with
57:18
the flow. And I don't want to do that. I don't
57:21
want that to happen to me. I don't want that
57:23
to happen to my family. And so I'm doing what
57:26
I need to do to... control that risk at least
57:30
to a reasonable degree for the end i wanted to
57:34
ask you a more broad question about navigating
57:37
this impossible informational landscape that
57:41
we're inhabiting right now where we're flooded
57:43
with information but at the same time it's hard
57:45
to know what's really backed up by science and
57:47
what's some random guy eating raw liver on tiktok
57:50
and telling you it's healthy as a rule of thumb
57:53
what kind of food or diet for lack of a better
57:57
word would you then recommend to ordinary folks?
58:01
You know, it's also a problem with these food
58:03
groups that keep changing. When I was growing
58:05
up, they said carbohydrates, that fats are the
58:08
worst. And then they were saying sugar is the
58:11
worst. And now I even read that protein is not,
58:14
if you eat too much of it, it can be inflammatory.
58:17
So it's not good. So, you know, it's always,
58:21
it's changing so fast that you can just give
58:24
up on all of it. I think there's some truth to
58:28
what you're saying. But I also think that what's
58:33
been changing a lot is kind of what is most prevalent
58:37
in our media environment, not necessarily what
58:41
the research is saying. So I do think the opinions
58:45
in the research community have shifted somewhat
58:47
over time around fat, for example. But the perception
58:52
that like... sugar used to be okay and now it's
58:56
the devil i don't think the research community
58:59
has really shifted that much on sugar i think
59:02
um maybe maybe to some degree it has but i think
59:07
it's always been viewed like you can go back
59:10
to the 1980 dietary guidelines for americans
59:13
in the u .s and one of the points it focused
59:17
on was eating less sugar so they cared about
59:21
it back then they care about it now but It's
59:23
not the boogeyman. It's still not the boogeyman
59:26
that it's made out to be in the media right now.
59:29
I think the importance of it has been exaggerated.
59:32
So that's just to say that I think we live in
59:35
an information environment with podcasts and
59:37
social media and things where things can change
59:40
really rapidly and it can be hard to get good
59:42
information. And a lot of the information that
59:45
is there is low quality. And that's the information
59:47
that people are mostly receiving. But that doesn't
59:51
necessarily reflect the best assessments by the
59:56
most knowledgeable people. And I think those
59:59
have changed to some extent, but a lot less over
1:00:03
time. Yeah, so I would say to someone who just
1:00:06
wants to generally maintain health and leanness,
1:00:09
what I would recommend is eating a minimally
1:00:13
processed omnivorous diet that is lower in calorie
1:00:17
density and higher in... Protein, the protein
1:00:22
you may or may not want to do, but that's more
1:00:24
for people who want to control body fatness,
1:00:29
who have that as a concern, may not be necessary
1:00:32
depending on your goals. And then if you're someone
1:00:35
who really is struggling with fat gain or you
1:00:40
currently have obesity and you want to lose weight,
1:00:43
you can use additional levers like you can increase
1:00:48
the protein more. And I'm talking about lean
1:00:51
protein, not protein that has a lot of fat associated
1:00:54
with it. And you can consider other approaches
1:00:59
like macronutrient restriction, like restricting
1:01:02
the carbohydrate, restricting the fat in the
1:01:05
diet. And you can also consider things like portion
1:01:09
control, which doesn't have a great track record,
1:01:13
but it is a tool that some people use successfully.
1:01:16
Very last thing. What about diets? I reckon then
1:01:21
you wouldn't recommend any of these like diet
1:01:23
fats such as like keto or paleo or Atkins, low
1:01:28
fat, whatever, gluten free. Is it beneficial?
1:01:31
Is it not? I think some of these diets can be
1:01:34
useful tools. I mean, I think they're tools in
1:01:36
the tool belt. And I think they work better for
1:01:40
some people than for others. But, you know, a
1:01:42
low carbohydrate diet, it's been around for a
1:01:45
long time and some people it works well for.
1:01:49
You know, I think the thing that the only caveat
1:01:53
I would have about it is that it tends to get
1:01:57
oversold. So people act like this is the solution
1:02:01
to your weight problem. Just go on a low carb
1:02:03
diet. And if and if it's not working for you,
1:02:05
just make it even more low carb and then go zero
1:02:08
carb. And if it's still not working, you're probably
1:02:10
not doing it right. You know, and the truth is,
1:02:14
like, these diets are not as effective as people
1:02:16
want them to be. But that doesn't mean they're
1:02:18
not effective. they can be effective and particularly
1:02:21
for certain individuals, they can be very effective.
1:02:24
So I think it's a tool in the tool belt, you
1:02:27
know, and some are better than others. Like the
1:02:29
low carb diets are pretty well established. The
1:02:33
only thing I would say is if you're going to
1:02:35
do a low carb diet, don't have it be just like
1:02:38
a, you know, processed meat diet, try to do more
1:02:42
lean meats and vegetables include some fruits,
1:02:46
things like that. It's fine to cut back on the,
1:02:49
The grains, those are not really critical elements
1:02:52
to diet, in my opinion. And then there are other
1:02:57
options like low -fat plant -based diets. That's
1:03:02
another pretty well -worn path that people have
1:03:05
done successfully. And there are other pitfalls
1:03:09
you want to watch for, like make sure if you're
1:03:12
not eating animal foods, take a vitamin B12 supplement.
1:03:15
That's really the big one. So I think there are
1:03:18
plenty of diets out there that actually do have
1:03:20
a fair amount of effectiveness. But really, you
1:03:24
just want to make sure that whatever diet you're
1:03:27
doing, you're sticking to having dietary diversity.
1:03:32
So you're getting all your nutrients. You want
1:03:34
to continue eating fiber. Don't go off the deep
1:03:38
end with these diets in a way where you're not
1:03:40
eating something that an expert would recognize
1:03:43
as a reasonably healthy diet. um as some people
1:03:48
do and very last question just because i thought
1:03:51
of it right now and your answer can be brief
1:03:53
we talked about goals we talked about how to
1:03:56
lose weight how to maintain a healthy weight
1:03:58
but what is a healthy body is this body type
1:04:05
that we're being sold i don't know in commercials
1:04:08
from hollywood you know guys that are really
1:04:10
jacked and for women it's different of course
1:04:12
is that actually a healthy body or not you know
1:04:16
all these muscles um that you probably don't
1:04:19
really need or should you aspire to be more lean
1:04:22
to actually be healthy or even have a little
1:04:25
bit of a beer belly i don't know you tell me
1:04:27
yeah yeah so i think certainly the the hollywood
1:04:32
body type is an unrealistic ideal for most people
1:04:36
and unnecessary um particularly when it comes
1:04:41
to the muscularity of the men Like if you go
1:04:44
back and you look at movies that were produced
1:04:46
even 30, 40 years ago, superhero movies and things
1:04:52
like that, people were not nearly as muscular.
1:04:55
The idea that superheroes or whatever protagonist
1:04:59
needs to be like extremely jacked, that's a really
1:05:02
recent Hollywood thing. So I think that kind
1:05:06
of body is unrealistic. I don't think it's necessarily
1:05:09
unhealthy. I think it could be if you start getting
1:05:13
into the really low body fat levels. I don't
1:05:17
think it's healthy to aspire to permanently have
1:05:23
body fat in the low single digits like a bodybuilder
1:05:27
would have during competition. And I mean, it
1:05:31
would be very difficult to maintain that regardless.
1:05:33
But there is such a thing as going too far. But
1:05:37
in general, I think having a lean body is a good
1:05:40
thing. I think the one of the, I would argue
1:05:45
that probably the number one driver of health
1:05:48
problems in the United States is excess body
1:05:50
fatness. And so, and in many other countries
1:05:54
as well, but I'm most confident about the United
1:05:58
States. And it probably used to be smoking, but
1:06:03
not as many people smoke anymore and people are
1:06:06
a lot fatter than they used to be. So I think
1:06:08
today it's probably. excess body fatness um so
1:06:13
i think having to a point low body fatness is
1:06:18
good not taking it to an extreme but to to a
1:06:22
healthy low body fat percentage and i think having
1:06:25
higher muscle mass is also good so i would call
1:06:30
that a you know favorable body composition taking
1:06:33
both the fat and the muscle mass into account
1:06:35
um but i don't think that it's realistic to aspire
1:06:41
to look like a hollywood actor for either men
1:06:45
or women right like that's just i mean that that's
1:06:49
just a psychological trap like you're never going
1:06:51
to be satisfied you probably don't have the genetics
1:06:54
to look like that the average person doesn't
1:06:56
have the genetics to look like that you don't
1:06:59
have the trainers and the money to look like
1:07:01
that you don't have the special effects and the
1:07:04
lighting to look like that like it's uh You're
1:07:07
just going to cause yourself psychological pain,
1:07:09
and that's not necessary for excellent health.
1:07:14
Dr. Guyanet, thank you so much. This was amazing.
1:07:17
Where can people get your book? Find bookstores
1:07:20
everywhere? Yeah, yeah. My book is available.
1:07:24
I don't know about internationally as much, but
1:07:27
it's available on Amazon here in the U .S. and
1:07:30
in English -speaking countries. In the US, it's
1:07:34
available in many libraries. I know it's available
1:07:38
in my local library. And internationally, I'm
1:07:43
sure you could order it through Amazon US and
1:07:46
maybe through your own country's Amazon. I'm
1:07:50
not sure about that. We'll include the link in
1:07:53
the description. Thanks again. Thank you. Thank
1:07:55
you so much for listening. There's a gazillion
1:07:57
podcasts out there, but you chose this one. So
1:07:59
I really appreciate your attention. If you're
1:08:02
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1:09:00
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1:09:04
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