ZOE Science & Nutrition - How to shrink the dangerous fat linked to heart disease and cancer in 12 weeks | Prof Jimmy Bell
Episode Date: August 13, 2026There's a hidden fat that matters more for your health than your weight. This is visceral fat: it wraps around your organs, raises your risk of heart disease and cancer, and builds up even in pe...ople who look slim and healthy. In today’s episode, Professor Jimmy Bell, a world-leading expert in measuring visceral fat, explains how we can shrink this dangerous belly fat in just 12 weeks. Jimmy explores why two people can weigh exactly the same and carry completely different amounts of this hidden fat, what it is, where it hides and why it matters. By the end, you'll have a completely new understanding of body fat, and what it really means for your long-term health. If your weight has stayed exactly the same for years, what do you think is happening underneath it? 🌱 Try our science-backed and tasty wholefood supplement Daily30 🌿Let your gut microbes snack on the ZOE Gut Health Bar Build healthy habits. Download the ZOE app today and start your trial for just £2.30 for your first week. 👉 Join ZOE Follow ZOE on Instagram. Timecodes 00:00 Intro 02:47 The DEXA scan result that didn't match how thin he looked 09:46 Why your body composition can get worse even while your weight stays the same 11:47 What does it actually mean to be "skinny fat"? 14:06 The real reason some people end up "skinny fat" 15:58 Why people carrying more fat might actually be happier 18:10 How visceral fat sends inflammatory signals through your body 21:50 Why having almost no body fat can also make you unhealthy 25:19 Could a supermodel have more visceral fat than a sumo wrestler? 26:44 Why your body stores visceral fat around your organs on purpose 28:08 Why visceral fat is the first fat to disappear when you diet 29:22 How your diet directly reshapes the fat in your body 33:25 How long it actually takes to change your body fat 35:47 Does Ozempic actually get rid of visceral fat? 37:05 Why dieting alone can quietly cost you muscle 38:55 What does yo-yo dieting actually do to your body? 41:20 The pattern he sees again and again in long-term dieters 42:39 Why being thin is no guarantee you don't have visceral fat 44:07 Why diet alone won't get rid of visceral fat 45:24 The exact mechanism that makes exercise target visceral fat first 49:03 Why inflammation and visceral fat together wreck your metabolism 49:50 Why any amount of alcohol is bad news for visceral fat 51:32 How fast visceral fat can actually shrink (as little as 12 weeks) 54:14 Why menopause redistributes fat to your belly 57:20 Resistance training: the single best thing for visceral fat 📚Books by our ZOE Scientists The Food For Life Cookbook Every Body Should Know This by Dr Federica Amati The Appetite Reset by Dr Federica Amati Food For Life by Prof. Tim Spector Ferment by Prof. Tim Spector Good Mood Food (preorder) by Prof. Tim Spector Free resources from ZOE The Smart Snacking Guide: How to feed your gut, fuel your day, and snack without guilt The Hormone Harmony Guide: Tuning Your Body’s Internal Orchestra Eating for Better Brain Health: Your brain-gut blueprint How to eat in 2026 - Discover ZOE’s 8 nutrition principles for long-term health Live Healthier: Top 10 Tips From ZOE Science & Nutrition Gut Guide - For a Healthier Microbiome in Weeks Better Breakfast Guide Mentioned in today's episode Fat cell turnover in humans, Nature (2008) New study investigates ‘optimal’ diets for healthy aging Study of visceral, subcutaneous, liver and pancreas fat changes after 12 weeks, Diabetes Research and Clinical Practice (2023) MRI assessment of adipose tissue fatty acid composition, Obesity (2024) Phenotyping, Body Composition, and Precision Nutrition (2024) Have feedback or a topic you'd like us to cover? Let us know here. Episode transcripts are available here.
Transcript
Discussion (0)
Welcome to Zoe Science and Nutrition, where world-leading scientists explain how their research can improve your health.
In the loud hum of an MRI scanner, a human body becomes transparent and everything changes.
What matters is no longer your shape or weight, or even what you see in the mirror,
but a layered landscape of tissues and organs that shape your health.
And somewhere in that unseen landscape lies a kind of fact that most people never think of.
about. It doesn't jiggle. It may not even show, but it wraps itself around vital organs in your
belly, quietly shaping metabolism, inflammation, and long-term health. This is visceral fat,
and it may be one of the most misunderstood biological forces in human health. We've all been
taught a simple story. Fat is bad, less is better, and thin equals healthy. But what if that story
is incomplete? Why can two people with identical
body weights had dramatically different health outcomes. What if someone can look thin on the outside,
yet carry significant metabolic risk within? And most shockingly, what if losing weight doesn't
automatically mean improving your health? Why does the body choose to store fat in different places?
And what can you do to change this? To help unravel all these questions, I'm joined by Jimmy Bell,
professor of molecular imaging and metabolism at the University of Westminster,
pioneer of MRI-based visceral fat research and a leading expert on the biological importance of body fat.
By the end of this conversation, you'll have an entirely new understanding of body fat,
how to distinguish harmless from harmful fat, how fat can shake your body's inflammation,
while measuring BMI is misleading, and specific ways to reduce visceral fat around your belly
through diet, exercise and behavioral changes.
Jimmy, if I managed to have very low levels of body fat, would I be healthier?
No.
Could supermodels have more visceral fat than a normal person?
Yes, I could.
If I have too much visceral fat in my belly, could it reduce my life expectancy?
Yes.
Is cardio exercise the best exercise to reduce visceral fat?
All exercises help to reduce fat.
Can fat tissue in my body influence my mental health?
Yes.
Can more visceral fat increase the inflammation in my body?
Yes.
I know.
What is the most common myth that you hear about body fat?
That all fat in your body is bad.
You just have to know how to treat it.
So I spent, you know, the first 35 years of my life being told I was thin.
And that all changed when we did our first big study at Zohort.
of a thousand twins. And I got to be a participant in this study. And as part of the study,
I had a full body dexas scan to measure my body fat and where it was distributed. And I will never
forget this experience. So the nurse is doing this scan. And she actually stopped and double-checked
the results. Because there I was, you know, on the table with very little visible fat on my arms,
my legs, but it turns out that I had lots of fat wrapped around the organs in my belly,
which is called visceral fat. And I was told that I was a toffee, thin on the outside,
fat on the inside. And that being a toffee was going to be very bad for my health. And this was
pretty scary and was probably the big aha moment for me personally that caused me to take my own
diet seriously. And it's exciting for me, Jimmy, that you're here today because you're the
scientists who invented this term toffee as a result of your research into the biology of body
fat. And it turns out that most of the things that I understood about fat were just wrong.
So maybe we could start with why it matters where in the body you store fat for your health.
And indeed, where is fat stored in your body?
Yeah. I think we should step back a bit and start talking about body fat, which is adipose tissue.
and other postage is an organ, so you have many components, and you have to think that those
components that make up that organ have very distinct anatomical and metabolic characteristics,
and it's very important where that fat is in relation to your health.
So you can unpack adipatio into many fat depots.
So the most common ones you know is the one which is outside your body, which is mainly
succulent as adipostitia, and then they say,
internal fat like visceral fat. Adipose tissue for me just means body fat. And so where are the
normal places that this is stored in my body? External part, which is called subcogenious adipose tissue,
and then internally the main one being the visceral fat or visceral tissue. And so if you're going to
tell me where in my body or a listener's body fat is being stored on that external place,
where does it mainly end up? Anywhere between your neck and your toes, you're going to find fat there
are going to have different metabolic effects.
So you have fat around your heart, fat inside your liver, fat inside your pancreas,
fat around your kidneys and inside the kidneys.
You're going to have things that are fat around your prostate, fat streaking your muscle.
You'll have fat around all your organs in the abdomen, which is called visceral fat.
And each one has a slightly different risk assessment when it comes to cardiovascular problems.
You're talking now about the fat that stored sort of inside my chest and torso.
Is that where most of the fat in my body is stored?
No, most of your fat is stored externally, which is tend to be metabolically less active than the internal fat.
So you could think of your external fat as a bathasone, especially if you're going around your hips and your thigh,
and the internal fat being more metabolically active and more of the internal fat being more of the
risk factor for condition like type 2 diabetes, cardiovascular disease, cancer, and so forth.
I feel like men and women tend to store fat differently, is that right?
We all store the fat in the same places. It's just a levels and difference. So there's a
hormonal genetic component to this. So men tend to deposit their fat more internally than
women. If you look at two males and females and look at the identical BMI, you'll feel
find that a male will have far more visceral fat than a female, but a female will have more
external fat than the male.
Men are having it more of the visceral is what we're describing sort of all around my belly
and there.
Where do women tend to distribute their fat?
Externally around the hips and the bottom.
Okay, so this difference is sort of true.
Yeah, this whole thing about one minute in the live, a lifetime in the hips.
It's actually, unfortunately, true for females.
And for a man, you're saying it's a minute on the lips and then a lifetime around my belly.
Yeah. And if you could choose where to store the fat to make sure that it was as healthy as possible, where would you put it?
I would become a sumer wrestler and have most of my fat externally.
Got it. And does it matter where it is externally in terms of the health impact?
Abdominally is left of a buffer zone than, say, your hip and your buttocks.
So that's a much more protective while this central part can be especially depends on ethnicity
and this ethnic issue as well, where this succoracinous fat can be proactive in terms of risk.
So I think what you're saying is that where women tend to lay down the fat, which is sort of
hips, thighs, bum, that's actually healthier than where men tend to lay down their fat,
which tends to be in this sort of visceral fat,
Yeah, nature was not very kind to men, I'm afraid.
Do we have any idea why men and women lay down fat differently?
That's interesting. There's been lots of speculation in there.
One is hormonal, and you see that in menopause, as women go into menopause,
they start getting more male fat distribution than a female fat distribution.
It might be just a dynamic thing.
If you're a hunter-gatherer, people suppose it's better to have your fat centrally,
So, you know, your central gravity is always in the right place.
And in the hips for women, it's because a fast story.
She's basically at the end of the energy.
You're storing for long-term survival, you know, maternity and so forth.
Then it makes sense on a evolutionary point of view.
In a modern world, of course, it doesn't make sense at all.
So you're saying that as a woman, because I'm going to get pregnant and have a baby
and need to breastfeeding things, like I need to store this back?
In the wilderness.
In the wilderness, because I won't be able to go down to the supermarket and get some food.
Yeah.
I just want to follow up on something else you said, which is that as you go through menopause,
your fat distribution shifts and becomes more like the male fat distribution.
What would that mean in terms of where my fat was before and where it ends up going afterwards?
For women, it means that I start getting more central fats, so away from the hips,
and more around the visceral area, around the organs, and around the abdomen.
and around their abdomen.
And so that could happen even if your weight was fairly stable?
Yes.
It's actually like a redistribution of what's going on.
Yeah, absolutely.
What we find it is people who keep stable weight,
keeping the fat and losing the muscle.
So the weight stays the same,
but the ratio between fat and muscle gets worse and worse and worse.
And so that's also true for everybody as we get older.
Even if your weight is stable, potentially you're losing muscle
and gaining fat.
And you're also, as a woman, seeing this fat distribution shift
from somewhere that you said was really healthy
to somewhere that is less healthy.
I asked a question about the healthiest place, to put the fat.
What are the worst places to store it?
I'll never forget the moment that everything shifted for me.
I was at a public talk on nutrition.
Listen to a speaker explained that my gut had trillions of microbes in it
and that these bugs shaped every aspect of my health.
That speaker was Professor Tim Specter.
one of the world's top 100 scientists, who became my co-founder here at Zoe.
Nine years later, Zoe runs the world's largest gut health research study.
And the conclusion is simple.
Gut health is health.
How you feel your long-term health and your digestion are all shaped by the state of your gut.
As a listener to this show, you know how important it is to feed your good gut bugs.
But I suspect that like me, you have a busy schedule,
and often you feel you haven't given them all the different plants they crave.
And that's exactly why we created Daily 30.
It's a gut health supplement packed with over 30 plants that you sprinkle onto any meal.
It tastes great, has a satisfying crunch, and gives your gut the diversity it craves.
Finally, a healthy, happy that's easy to stick to.
I should know, I take it every day.
And because we're Zoe, we don't just guess.
We test.
We put our original Daily 30 formula through a randomized controlled trial, the gold standard of testing.
The results blew us away and proved it supports your digestion.
energy and gut health. That trial helped us develop the formula we have today. Today, Daily 30 is a
non-negotiable daily habit for me. So don't put your health off for the future. Go to zoe.com
slash Daily 30 and try it today. So in a pecking order, if you like a perking order, I would start
visceral fat, then liver fat, pancreas fat, and then what we call eye mat, which is the intermascular
fat. So that's a fat that streaks across your muscle. All those fat are independently risk factors
for type 2 diabetes, cardiovascular disease, metabolic diseases. But the main two culprits at the
moment are seen visceral fat and liver, which are interlinked. There is an axis between visceral
fat, pancreatic fat and liver fat. And lately it's become very clear that the amount of fat that you
deposit in your muscle can be very, very, very dangerous.
detrimental, especially as you grow older.
When you started to differentiate between visceral fat and liver fat, I'm like, you know what,
I'm a bit vague really about what's really going on inside my body.
Could you help me to understand a bit more what visceral fat therefore means?
Yeah, we call visceral fat in general.
It's a fat inside your body around the organs in your abdomen, anywhere from the top of your liver
down to your hips.
And if it's inside, it's generally called abdominal fat or visceral fat.
Got it.
And so I think historically, I've tended to think about belly fat as being an aesthetic issue.
But actually that belly fat, which we think about as being aesthetic,
your research is saying that this really matters about health.
So can we go back to that term toffee that I learned about during my own scan?
Because I had never heard of it before.
What does it mean?
And why is it possible that you can look thin on the outside but be fat?
on the inside. So initially we used to do measurements of body composition indirectly. So we use a tape
measure, we have calipers to measure the thickness of a fat, and the waterway. So you put someone in a
swimming pool and see how much it displays and work out density and so forth. When imaging came along,
especially CT and MRI, we realized that we can start looking inside people's body. And we
discovered, and this is with one of our colleagues, Gary Frost in Pure College, who said, look,
I got people with identical BMI, identical body composition by all these measurements, but the
insulin sensitive is completely different. What happens is you scan them. And we scan them, and one of them
has no internal fat, the other one has lots of internal fat. I said, that's it, your answer.
They look the same on the outside. Absolutely. They had the same BMI, same age, same ethnicity.
Everything was same. And BMI is basically sort of their weight compared to their heart.
It's like a traditional measure of whether you're thin or fat.
And so they look exactly the same.
They're the same on all of these traditional medical ways to judge your health.
But metabolically, metabolically, they were different.
And you were saying one of them was really not in good shape, metabolic?
Yeah.
And the other one was.
It made no sense.
So when we scanned them, one has lost internal fat.
And then we started looking at this.
Oh, yeah, this is happening.
And then we started seeing that there was a small percentage, including myself,
that actually we had the knowledge.
normal healthy BMI, but the amount of fat internally was disproportionate to the amount of external
fat. We used to have this very long word to describe it. First, someone came out with the Toffee.
It was one of the reporters who actually said, oh, you mean thin outside, fat inside? We went,
oh, yeah, okay, yes. Well, you get all the credit for it now, J. J.B. Serious. I know, I know,
but I have to get credit to people. Scientists are not very good at transmitting our findings.
And do we have any idea why it is that you could end up as this toffee?
I think it's mainly because lifestyle choices.
At the time, there was a lot of emphasis on diet and for a long time being just diet and maintain your weight.
And it was all about weight.
Not the quality of the weight, just the weight.
So if you tend to maintain your weight mainly through dieting, you end up having the wrong body composition.
Because as you put weight on, you put a disproportionate amount of fat on, a very little muscle.
So your ratio of fat to muscle gets more and more detrimental.
And this is why you end up with a situation where you might maintain the right weight, but the wrong composition.
This does not happen if you maintain your weight with exercise.
The thing that to me seems most surprising is I've always thought about fat is it's just a way to store.
calories for later use, you know, like a bear getting ready for hibernation, you know, it's eating
all the salmon, it gets really fat, it goes away and like hides in a cave and slowly it depletes
the fat. That's the only thing it does. So it's like completely dormant way to store energy. Is that
correct? That was the thought until about 20, 30 years ago. This was all changed when they
discovered that adipostitia creates molecules, one of them, the most famous being leptin,
that affect your appetite.
And bit by bit, people transfer the adiposision from a tissue,
which is very passive, to an organ,
which is a very active component of your body.
And now adipose tissue is your friend
that tells you about the outside,
and it tells you about the inside of your body.
External is telling you about food and energy availability.
Internally, it's telling you about moves,
about your biological status and so forth.
That's why people who tend to be large, tend to be happier, yeah,
because it's that balance that you have to find
between having enough energy without creating metabolic problems.
You could think other positions as a brain,
and it's actually all the time aware of what's happening to your body,
internally, in terms of energy, in terms of inflammation,
in terms of all the processes happening inside your body,
and it's responding to that.
If the energy is too low internally,
let's release fat.
It's too much, I'll store some.
If there is inflammation, I will release some chemicals.
If there's too little, I would release the right energy
so those chemicals can be produced.
And at the same time, it's very aware of the outside.
If there's no food, let's store it very quickly
because we might need it a long term.
So, you know, it's protecting you from bumping into things
and if it's too cold, if it's too hot.
So it's a very dynamic system.
It's a friend that might love you a bit too much when you love it too much.
There's a bit the way that I feel about ice cream.
You said something about how it could affect your mood.
Could you help me to understand that and something to do with being happy?
Yeah.
So one, adipatio affects your appetite, but also the inflammatory marker.
So it's inflammatory chemicals, okay, that the adipose tissue is actually reacting to.
And that inflammation, again, affects your brain function.
And these have been shown already.
So when you put weight on and you become obese, you get subclinical inflammation.
So it's not inflammation you're getting arthritis, but it's just much lower.
Yeah.
And that is affecting your mood.
So it's like if you receive an injury, it's an animal.
injured, you get a massive inflammatory response to repair that injury.
And animals go and sit in a corner until they get better.
When you become obese, you don't get that kind of massive inflammatory process, but much
lower.
So you still feel that you're injured, but you're not quite injured.
It's all the fat in your body is actually sending out these inflammation markets?
Especially your visceral fat and your saccharacterium's fat, but the visceral fat is quite central.
So when you get a combination between inflammation and visceral fat, that is a very bad combination.
So this visceral fat around my belly, if I've got lots of that, it's not just sitting there doing nothing.
It's actually sending out inflammatory signals to the rest of my body.
And if I've got a lot of it, it's like sort of always on pumping out of this information.
And on top of the inflammatory cells come to the visceral fat and makes it even more excited.
So it becomes a vicious circle.
Also, if I have other inflammation, which I might well do in our modern world, how do your fat cells respond if that inflammation is going on?
The mechanism are not clear at the moment, but clearly they start pumping out more inflammatory signals.
So it becomes a vicious circle, which attracts more inflammatory cells.
So my inflammation is up, and then if I have a bunch of this visceral fat, it then pushes out more inflammation, and then the rest of my body goes, oh, the inflammation is worse, and it's a vicious circle.
And it tells you, you go and sit in the corner until you get better.
But of course, you're not going to get better because you're obese.
So talk to me about the sitting in the corner.
How does this tie to my mood that you're describing?
If an animal is injured, you'll see they become very passive or the sitting in the corner
until that injury gets resolved.
And while the signals to tell it to come down and sit in the corner and just kind of, you know,
is the inflammatory signals.
But when you go obesity, you got the inflammatory signals without the injury.
So your body is telling you, look, there's inflammation, you should be more passive, and it will
resolve this problem.
But that problem is not going to resolve because you're not curing an injury or a wound.
You just got this subclinical levels of inflammation that are affecting the way you're going to
behave.
How will this make me feel?
less likely to become active.
It's a very open question at the moment
is the whole area of how moods and behaviors
affect the body of post tissue, but it definitely is affected.
One of the things we see a lot through, like, the gut health research
we do at Zoe is the way in which, like, improving your gut health
has this really positive impact on mood and energy,
like very dramatic and quite fast.
Are these a similar sort of self-reported feelings that you would associate with this sort of excess of visceral facts?
Yeah, absolutely.
And if you resolve that, you resolve the problem.
So you resolve the problem, visceral fat, having too much and having it inflamed, yeah?
You will resolve loss of the problem at the same time.
But the body is telling you, don't do anything until we resolve the problem.
But the problem is, yeah, the problem in itself, if that makes sense.
It does make sense.
So it sounds pretty clear you don't want to have too much visceral fat and I guess not too much fat overall.
Wouldn't I be better off in today's world having almost no body fat?
Because after all, I can always go to the supermarket and buy more food.
So I don't need to have it stored in the same way that are ancestors.
So shouldn't I be aiming for almost no body fat?
if you think of body fat simply as a dumping ground for excess energy.
But we already established that it is an organ, it has other functions.
It has function in fertility, has functioning in your moods, the way your immune system works.
So if you don't have any adipost tissue, there are a condition called lipodistrophy,
genetic condition where people have almost no fat because of genetic reasons,
they end up having type 2 diabetes.
So you end up with having no fat, and all the,
the problem of obesity.
So you can have so little fat that it's really unhealthy.
Because the fat has to go, there's fat in your diets.
You can't get away from fat.
Everything you eat has small amount of fat in it, larger or small amount of fat.
That has to be stored somewhere.
So if you don't have adipose tissue, it will be stored inside your liver, inside your
pancreas, inside your muscle, in all the wrong places.
The worst places that you can think of.
So that's why.
adipat tissues your friend.
I said, okay, I'll store away that excess in a good place.
But if you do overdo it, I have to put it somewhere.
And in your view, Jimmy, because this is your area of research,
do you feel that this adipose tissue, this like storage of fat,
is it doing any positive things for us now that we understand it's more like an organ
that's active, or is it only sort of a risk of danger if it's in the wrong place or there's too much?
Everything that the fat does is good.
One store energy, maintain your immune system.
So if you get an infection, adibust tissue is there working for you to stop that.
If you get wounded, adipatio is there, giving you the chemicals to repair the wound.
It's keeping you warm.
It's keeping your mood up.
You know, it's doing lots of good things.
I'm thinking about this, sumo wrestlers and supermodels at the other end.
Supermodels are obviously famous for like having almost no body fat.
No, no, no. The famous of being very thin.
Okay.
Nobody has done a really full study of their body composition.
We try to do this, and unfortunately I made a mistake of telling them what I was trying to show
that their body composition was not healthy.
You see, models as far as I understand, not that I know any supermodal, they are not allowed
to have any muscle delineation.
Therefore, they are not allowed to actually exercise, because otherwise they can say.
They have to be smooth.
The stupidity of the industry.
And the only way you can achieve that is through dieting.
And when you lose weight, you lose muscle as well.
So in the supermodel, we got no idea what the body composition is.
But what is your guess?
My guess is that it's not very healthy.
So your guess is they do have fat, but only sort of this visceral fat around their organs?
Yeah.
And probably in the liver as well.
The two models that we managed in scan, they did not have very healthy body composition.
They had too much fat in their body.
even though they look very thin.
And how does that compare with a sumo wrestler?
They seem like the definition of incredibly unhealthy
because they've got this enormous amount of fat
folding over them.
So I would assume that they are like vastly less healthy
than a supermodel.
I follow sumo wrestling.
But they do six to eight hours exercise.
And in Japan, through decades or hundreds of years of trial and error,
they come out with a regime that they,
accumulate fat, but most of the fat accumulated externally. So you see them really large. When you actually
they are done CT scans of sumo wrestlers, the amount of visceral fat is very low, extremely low,
surprisingly low. And so they have been scanned? Oh yes, yes. And so potentially a supermodel might have
more visceral fat than a sumo wrestler? Could be. We're talking about Japanese sumo wrestler
Because a lot of Western sumer wrestler that don't follow the same regime, and they're very large.
And those people are not exactly what I would call a sumer wrestler.
If you look at the sum of a wrestler in detail, they got huge ties.
Huge thighs means loss of muscle, good quality muscle.
And that's another important thing.
So why is it that we accumulate fat around our organs if it's so unhealthy?
Because you'd think our body would know that.
wouldn't lay down fat in these bad places when it's got perfectly good places.
I'm looking at my legs and my arms and thinking, you know, my butt, why can't it put the fat there?
Okay, so imagine you are designing a system and you think, okay, I got two functions that I have to do.
One, store excess energy.
And you say, okay, I'll put it outside.
Because when I need a slow process, I put it outside.
It also protect me from the cold and bumping around into things.
Then I need another dynamic system where I need it for my inflammatory responses, infections.
Most people, you know, a thousand years ago, used to die from infections.
Well, your adiposteatia and your visal fat is quite key for inflammatory responses to infections.
So that's why you put it there.
Of course, in modern world, you just take antibiotics and that's that.
So you would put some fat inside your organs in order to support your immune.
system really fast. Around your organs. So it's actually literally to support somehow like the
inflammatory processes that you need for infections. So there's a bit that's around these organs
that I can get to very fast to support my immune system to fight some sort of infection.
Your visceral fat is metabolic very dynamic. So it responds very quickly in comparison to your
circuitous fat. And what does respond quickly mean? In terms of it doesn't have to have lots of signals.
it responds to immediately.
So if there's an infection,
inflammatory cells require fat,
they require signals, okay?
It responds immediately.
So it's sort of like I can access it very, very fast,
is that we're saying?
So there's visceral fat, and theory I can pull out really fast.
Yeah, but your sacchargeneous fat doesn't.
So that takes time to pull down.
Especially if you're around your hip.
Okay, it takes even longer to your response.
And so the idea is I'm storing that.
This is sort of like my immediately available petrival,
tank for this.
Yeah.
But your expectation is you'll sort of run that down quite fast, which I guess these days
that's not what happens and it just sits there for years slowly growing.
Yeah, but it's very responsive because if you do diet, one of the fat depots that decreases
the most, okay, is the visceral fat, because it's very responsive.
The same with exercise.
The same with liver fat.
So they all have their resources.
Just too much is a problem.
Too much with inflammation on top of that.
it's a bigger problem.
Then the composition of the fat is also important.
What do you mean by that?
So whether it's saturated fat or unsaturated fat,
that in itself is a risk factor.
So our body can lay down different types of fat?
Yes.
Could you explain that to us?
So, well, it reflects very much your diet.
So if you eat loss of saturated fat, you know,
if you go to McDonald's, I eat lots of fatty food, you know,
with saturated,
that's what your body's going to look like.
We can measure the amount of saturated.
saturated fat or unsaturated fat, you want to have as much unsaturated fat as possible.
So if you look at vegans, who tend to eat a healthier diet with lots of unsaturated fat,
even though the amount of fat is the same, the composition of that fat is different.
And is it the composition that's more important?
No, no, it's the amount, the distribution and the composition.
Got it. But what you're saying, let me just understand that.
If I eat lots and lots of red meat, then actually slowly my body sort of resembles the kebab or the burgers that I eat.
But on the other hand, if I am eating lots of avocados, then actually the fat, I look more like an avocado inside me.
Exactly.
Well, all your fat, not all your fat, all your fat.
All my fat.
So your body actually reflects the type of fats.
Even the fat in the bone marrow, it reflects your diet.
And that is a risk factor in itself.
So it compounds.
So if you have visceral fat that is very saturated,
it's worse than having visceral fat that is unsaturated.
So eating a really fatty piece of meat is likely to be worse than like a lean piece of meat
because I'm just going to take that fat from, you know, the cow or whatever.
And body body's like, great.
That's what we're going to be laying down around your liver tomorrow.
Yeah.
If you have olive oil, okay, and the same amount of sunflower oil, then the olive oil is going
to be much better because that's what is going to reflect in your body.
And when the immune response occurs, okay, the immune response needs loss of polyunsaturated fat.
It doesn't need the saturated fat.
That's the first thing that gets moved by the body is the unsaturated fat, because it's
essential for the immune response.
And if you go trans fat, that's even worse because you can't move there at all.
So you can see the complexity of this organ.
So let's say someone is listening to this and they're like, you know, I've been thinking about changing my diet for a long time.
I know I'm eating way too much like red meat and bacon and all these sorts of things.
And I want to switch towards like a sort of Zoe style diet that's much higher in plants and healthier fats.
Will the fat in my body turn over?
Is it all too late?
No, no.
How long does it take?
So a Swedish group from the Karolinska Institute did a beautiful study and where they
showed and the measure the turnover of adipost tissue.
And it takes between two and three years, okay, to turn over your adipost tissue.
So your father will take between two and three years.
So if you change your diet now, it sounds depressing, but it's not.
It will take you about two to three years, okay, to change from a saturated meat-looking
person to unsaturated avocado-looking person.
In biology, everything takes time.
I always say, nobody goes to bed thin and wakes up in the morning of the weight.
It's a long process.
Your body didn't become saturated overnight.
It's a long process.
There's almost like two benefits here it sounds like.
One is you're going to lose the visceral fat and that's going to be healthier for you.
Is that correct?
That's right.
But the second thing is you actually would like to change the composition of your visceral fat.
There's not just the amount.
Yes.
There was this amazing study published a couple of years ago looking at improvements in years
of life if you switch from like the standard poor quality diet in America or the UK to sort of a high quality diet.
And the thing that stuck in my mind the most is you could be like 70 years old and you could switch to a high quality diet and you could live for like another six or seven years, which is sort of crazy.
But now I'm listening to this.
Is this the sort of thing that can explain that?
because you're actually, like, after a year or two,
like your whole body fat is turned over to something much healthier?
Yeah, absolutely, yes.
It's a part of this.
When people lose weight through dieting,
if that's what they're going to do, it's not what I'll recommend,
but they should not only reduce the amount of calorie they take in,
but also the type of calories because you get double benefit.
You lose the weight and you change the composition of the adiposteatia,
which will help dampen down your inflammatory,
responses, it will improve your inflammatory responses. And with that, there are many things.
Inflammation is a massive thing, you know, beyond my own expertise, but something quite
important to keep an eye on. There's obviously an enormous interest in weight loss drugs
at the moment and sort of dieting and yo-yo dieting. If I start taking like these GLP1 drugs,
like a Zempic or Wagovi, do we know what that does to?
our visceral fat as opposed to, we know it reduces our overall fat?
I find GLP1, I got an amazing track.
I mean, they work.
They work.
They don't work for everyone.
And the mechanism is still unclear, at least for me, but they work very effectively.
So the discussion then became what's so weight do you lose?
If you diet and you take GLP1, do you end up with the same?
same body composition on the end. And this is the big open question. So visor fat drops,
because if you lose weight in any form, visceral fat, liver fat, drop. That's the first fat depots
that you're going to say drop it. Second, the quality of your muscle in the sense that how
much fat you have streaking across your muscle also decreases, which is also a positive thing.
And we haven't spoken about the value of having loss of muscle and the quality of muscle.
So it's not only amount of muscle, but the quality of that muscle.
Now there is a discussion as to how much muscle you lose when you diet.
So you do diet alone.
You decrease, say, your intake of calorie by 50%.
You lose fat, but you also lose muscle.
So you don't end up in a good place.
If you don't do any exercise.
In the GLP1 agonist treatment, we don't know how much muscle people are losing.
The literature is quite contradictory, but there hasn't been a proper study, at least published study.
It might be that the pharma companies are doing these studies.
I don't know.
Again, I'm not privy to that, but we don't know how much muscle and the quality of the muscle they are losing.
And this is worrying because if there is an excess of muscle being lost, not only fat, by excess of muscle in comparison to how much fat you're losing.
So if you're losing the wrong amount of muscle and the wrong type of muscle, you might be,
creating in future a pandemic of, you know, psychopenia and all related conditions.
And so this is back to a little bit, your supermodel conversation, isn't it, where I've clearly
lost weight on the outside, potentially on the inside, I've still got like these pools of
fat in these really dangerous places, there's visceral fat, and I've just lost a lot of muscle
that I don't see. So we might look at someone and say, hey, you look great. But actually, you know,
if I had the scan in my eyes, I'd see, oh, you've lost a lot of muscle. And so you need to do
something around that at the same time as you're losing weight. Yeah, absolutely. To be fair to the,
which I'm never fair to a pharma company, but it would be fair to them. They do say the people that
take GLP1, they should include exercise as part of their lifestyle recommendation. And I think
this is important. And this is important in any way that you lose.
weight. I was going to ask actually, Jimmy, what about people who have been doing this sort of
yo-yo dieting in the past, which is incredibly common? In fact, it's been promoted really by our
culture. So, you know, you do a crash diet, you lose some weight, you put it back on, you do a
crash diet and repeat it. What does that do to, like, my visceral fat and my body composition?
Well, what it does is, and I think that's why I want to bring skeletal muscle into the conversation,
because muscle can work as a counter to some of the problem, the antipost tissue.
So when people diet, okay, they lose fat, but they also lose muscle.
So the ratio, fat to muscle becomes worse.
When you put weight on, that ratio becomes even worse.
So you have too much fat, but a little muscle.
You lose weight again, that ratio gets even worse.
So as you yo-yot, your fat to muscle ratio becomes.
worse and worse and worse. So the recommendation should be that if you lose weight in any form
of shape, you should do exercise because you lose weight but you put back that muscle. So you might
you might end up with the same weight that you want to achieve, but the composition will be the
proper composition. The muscle is actively beneficial. The muscle is absorbing loss of the sugars,
you know, it's metabolizing it. Besides the mechanical,
need for walking and so forth,
especially as you were older.
It also sending signals
in the rest of the body. So the muscle now
is producing lots of signals, and we
detect the signal, that changed the metabolism
around your body. So when you
exercise, you're not only just burning
fat and growing muscle, but you're sending
signals around that change your mood,
change your immune response,
change your metabolism. But it's not
only the amount of muscle,
but it's the quality of that muscle.
So you can have lots of muscle, but with lots of
fat infiltration, that's no good muscle.
And what I'm taking away from this conversation is that, you know, if you're someone who's
been a yo-yo dieter in the past, if we were going to go and sort of do that scan between
you and maybe, you know, how you might have been 10 years before, even if you had the same weight,
actually you're going to probably have more visceral fat and overall you're going to have more
fat and less muscle than someone who's never been through this like cycles of weight loss
and weight gain and weight loss and weight gain.
People who maintain their weight
through diet throughout their life,
the body composition is getting worse and worse,
even though the body weight stays the same.
If someone in your life is focused on losing weight
and has spent years bouncing from one diet to the next,
send them this episode.
It might help them realize that improving health
isn't always about getting lighter.
Sometimes it's about nurturing the right kind of fat.
So I'd love to move now,
to, okay, what can you do about this? How can I reduce my visceral fat? But I'm also thinking that,
you know, I got this scan that actually told me, wow, you've really got this visceral fat,
but most people have never had a scan like that. So if someone starts by saying, well,
I want to know how much of a problem this is, you know, is, for example, measuring their
BMI a good way to start to figure this out? Yes, and no. So if, if,
If you're overweight and obese, it's highly likely, and you don't do any physical activity
as such or exercise, it's highly likely you've got very high levels of visceral fat, liver fat,
pancreas fat, and lots of fat in your muscle.
And what about the reverse?
Let's say you're listening to this and, you know, the doctors haven't been telling you
that you're overweight, but now they're listening to this and thinking, oh, well, actually,
maybe I do have the visceral fat, which was absolutely in my situation.
situation a few years ago. Is there any way, like from your own lifestyle or anything else
that you could...
Okay, so if you have a large BMI, it's almost guaranteed that you have lots of visceral
liver and pancreatic fat and muscle fat. If you're thin, normal BMI, there's no guarantee that
you don't have lots of visceral fat, liver fat, pancreate fat, and muscle fat. Now, if you're
thin and your lifestyle includes a balanced style.
and significant amount of physical activity,
it's highly likely that you have the right levels of fat
distributed around your body.
So that's almost guaranteed.
If you maintain your weight through diet alone,
it's highly likely you've got loss of visceral fat and liver fat.
I almost can guarantee it.
Let's talk about what you can do about it.
Let's say, listen to this and you're like,
I'm worried about the visceral fat.
I want to reduce it.
other than medication to reduce your weight.
We talked about GLP ones.
You said that will reduce your visceral fat along with everything else.
What can people do?
I'll never forget the moment that everything shifted for me.
I was at a public talk on nutrition.
Listen to a speaker explained that my gut had trillions of microbes in it
and that these bugs shaped every aspect of my health.
That speaker was Professor Tim Specter,
one of the world's top 100 scientists,
who became my co-founder here at Zoe.
Nine years later, Zoe runs the world's largest gut health research study.
And the conclusion is simple.
Gut health is health.
How you feel your long-term health and your digestion are all shaped by the state of your gut.
As a listener to this show, you know how important it is to feed your good gut bugs.
But I suspect that like me, you have a busy schedule, and often you feel you haven't given them all the different plants they crave.
And that's exactly why we created Daily 30.
It's a gut health supplement packed with over 30 plants that you sprinkle onto any meal.
It tastes great, adds a satisfying crunch and gives your gut the diversity it craves.
Finally, a healthy, happy that's easy to stick to.
I should know, I take it every day.
And because we're Zoe, we don't just guess.
We test.
We put our original Daily 30 formula through a randomized controlled trial, the gold standard of testing.
The results blew us away and proved it supports your digestion, energy and gut health.
That trial helped us develop the formula we have today.
Today, Daily 30 is a non-negotiable daily habit for me.
So don't put your health off for the future.
Go to zoe.com slash Daily 30 and try it today.
I'm not going to comment about diet.
I'm not an expert on diet, but clearly there are lots of advice on dietary intake amount of energy.
But I think if you're overweight and you go into a dietary regime or reduce calorie intake,
improve the quality of that diet,
that energy you're taking,
and add exercise.
So the weight loss
lead to a reduction
of visulfide and liver fat and so forth.
If you have stable weight,
diets will have very little impact
on the amount of visulphan.
It will come down to physical activity,
to a gym.
To build your muscles,
so resistant exercise,
appears to be a very important
component of this.
And you have to get out of breath when you do physical activity, yeah, to start burning that fat.
Because when the body start burning that excess fat, the first areas that will go to pick up that fat to burn it will be in the liver, will be in the visceral area, will be in the pancreas.
And we and other groups have shown this over and over again.
And long walks, not just talking to your friend, which is good, okay?
but you have to get out of breath, walk fast.
So the speed becomes actually quite important.
And you've shown that if you get out of breath when you're walking,
I'm not talking about trotting, I'm not talking about running,
but just taking that pace up a bit.
You'll get all the benefits of walking and more.
So what you're saying is that when I start to do exercise
at a certain level of intensity,
then it's like pulling this visceral fat out?
Yeah, you need energy.
When you do exercise, you need energy.
You have to take it from somewhere.
And the first place after the sugar will be the fat.
And the first place it will come out
will be the visceral fat and the liver fat,
all the bad depots.
Because it's a very mobile,
metabolically, very active depot.
And when you exercise,
your process doesn't stop when you stop exercising.
The effects carry some four hours,
you're not days.
And this has shown that your metabolism changes.
Days after this is not the work that we're done by other people
are actually shown that that metabolism is altered very quickly.
What exercise would I do would be resistant exercise
because, too, you're not only burning fat, but you build the muscle.
And again, we must have look at fat in isolation.
It's part of a bigger system.
And there's a counterpoint which are called skeletal muscle.
So if you build good quality muscle, it will counter some of the detrimental part of the other fat.
And we see this in the sum of restless.
So if you have to do some exercise, resistant exercise will be, especially if you're older
because you're building muscle.
Aerobic exercise, it will give you other benefits, you know, your respiration, the way you breathe
and so forth, you'll feel fitter and it'll give you a high.
Can I ask about now about this sort of nutrition exercise tradeoff?
because I think that many people that I meet talk about, you know, any form of weight loss
as being sort of 80% your diet and 20% your exercise.
And that despite all the discussions about exercise driving weight loss, like the evidence says
that isn't really true.
It's great for your health, but it doesn't lead that.
It sounds like, though, when you're talking about the visceral fat and the impact on my health,
that you're waiting the exercise much more?
People are obsessed with weight.
Yeah.
They're not obsessed with health.
And this is the problem.
And we did a study where we had 20 or 30 women
and we put them through lots of exercise and diet as well.
And metabolically, they all became really healthy.
And body composition, they all became very healthy.
They all complain that they still look the same.
If you want to lose weight really quickly, diet.
and you're going to end up with the weight that you require.
Are you going to be healthier?
Yes, that in comparison to where you started from, if you were overweight or obese.
Of course, you're going to be healthier.
But if you diet and you did exercise at the same time, you end up with the same weight and a much healthier profile.
And this is the thing.
So it's not exercise and it's not diet.
It's a balance between the two.
So you cannot eat yourself out of a gym, but you cannot exercise yourself out of a bad diet.
So I'm thinking now about food, and I think we've already talked quite a bit about how the type of fats in your diet really affect the type of fat in your body, and that has its impact on your health.
In a similar way that you're saying, we avoid this sort of unhealthy, you know, saturated fat from certain sources.
Is there anything else that we should be sort of avoiding in particular that is sort of directly sort of linked to this visceral fat build up?
I think the big umbrella that covers this whole thing is inflammation and your immune system.
So diet that would lead to an increasing inflammation and inflammation response, then that's a really bad combination if you've got loss of visceral fat.
These are two brothers that get together and they just mess.
around with your metabolism.
So, like, I'm eating food the increase of my inflammation.
That will trigger the visceral fat to be inflamed.
It responds to say, oh, we're in flame, okay, let's all get inflame, okay?
And then, yeah, you're in flame, I'm inflamed, let's all get inflamed.
And it becomes a vicious circle that you want to avoid.
So by having the right amount and the right composition of visyl phar, but then the diet
that doesn't trigger further inflammation, yeah, it becomes important.
So it's not only about the composition, so there are things.
What about alcohol?
In my mind, this sort of beer belly, you know, I have this sort of direct link between,
particularly like beer and having this sort of massive sort of visceral fat.
Is there anything in this?
Yes.
Any amount of alcohol is best for you.
That's it.
I know that the French say that you take red wine, they're in this correlation and so forth.
But it's not the alcohol per se.
It's the other components.
You could take those components without having to have the red wine to get the benefit.
in moderate amount of alcohol, it's not bad for you.
I mean, it's not terrible.
So moderation, the Chinese have been saying this for about 10,000 years.
Everything in moderation will be okay.
Alcohol in moderation.
People don't drink alcohol in moderation.
So you go the energy intake and then the alcohol that have detrimental effect,
especially in your liver, increases inflammation.
We're back to inflammation.
The whole process of subclinically level inflammation and so forth.
So in your view, the alcohol, it's not just the,
The calories in the beer, the alcohol is having an effect that leads to more of this visceral.
Yeah, because you already have a problem and then you hit it with another problem that
triggers a massive response.
So if you're very healthy and you drink a beer of alcohol, that's fine.
But most people who drink alcohol, they're already unhealthy.
Too much visceral fat, too much fat in their liver, too many toxins in their bodies.
And then on top of that, they hit them with alcohol.
The alcohol is creating damage in your liver and all the organs, okay, that triggered
lots of free radicals, it's aging you faster.
So if someone's been listening to this and they found the whole story really compelling,
Jimmy, and so they start to eat better, they start to exercise more, just as you're
describing, how quickly can they lose this visceral fat you're talking about that has
so much detrimental impact on their health?
We had done interventional studies where we've shown within 12.
You can see a significant change in liver fat, visceral fat, pancreas fat.
Within 12 weeks.
Yeah.
And that's not some totally crazy crash diet?
No, no.
It was a significant reduction of a calorie intake and the quality taking.
This is in 12 weeks, you can have a significant improvement in your visceral fat.
There's actually like a very short period of time that you're saying, and that would have really
like meaningful improvements in your health?
Yeah.
your metabolic profile. Absolutely. Amazing. Final question, Jimmy. If someone was listening to this
and they want to improve their long-term health, what's the one thing that you would recommend
they start doing today out of the, you know, the many things we've talked about? What would be the
most important thing you'd suggest they should do? It depends on the starting point. So I would say,
look at your diets and look at your resistant exercise. If you just include that in your day-to-day
control the quality of your diet, you can have a massive impact, both on the composition of your
body and the quality of the body. Jimmy, I think that's really clear. I'd like to try and do a quick
summary. The thing that really stick in my head right now is this image of sort of the supermodels
on one side and the sumo wrestlers on the other. It seems really obvious that the supermodels
have no fat, but actually, if the supermodels don't do an exercise. If you were to scan them and
understand their visceral fat, there's fat around their bellies, you could actually find
that the supermodels are worse than the sumo wrestlers, which I find extraordinary. And that's a
problem because this visceral fat is really important for your health. And fat isn't just this sort of
store of energy that has no impact on our body, we now understand it's this sort of organ,
which responds to inflammation in our body by then producing more inflammation if that happens,
which can then lead to more fat. And that's particularly true if it's your visceral fat around your
organs, it's all much more active. And so given that we live in this environment where in general,
we have this high sort of background level of information, you then have this fat and you're in a
sort of vicious spiral, which is why having lots of visceral fat is really bad for your long-term
health. If you're listening to this and you're a man, then you're already, you sort of draw on
the short straw because you're naturally putting much more fat into visceral fat than women do
who tend to put it into their hips and their bums. That changes for women as they go through
perimenopause. And because of those changes in hormone, it's just a fact that even if they're
keeping their weight the same, it's going to redistribute towards their belly and towards
the visceral fat.
And so although you're eating in just the same way and you're doing the same things,
like your body is changing and, you know, that's just a reality of this hormonal change.
But it matters because putting on that visceral fat is bad for your health.
The other thing that I'm really struck by is this idea that if I eat McDonald's,
my fat is basically McDonald's.
If I'm eating avocado, then all the fat on my body is basically avocado fat.
And that's really crazy because you literally are what you eat is what you're saying, Jimmy.
The bad news is that it's not going to change instantly, but the good news is you can change it.
You're not stuck with it for the rest of your life.
So even if you just keep your fat levels constant, after two to three years of eating a healthier diet,
you could have turned over and replaced all of that unhealthy fat with the healthy fat.
And I guess this also talks to the fact that you can get a lot of benefits from a healthy diet fast.
But if you can sustain that for two or three years, then you start to get this amazing benefit.
And if we talk about certain fats like the fats in red meat as being unhealthy, that's also true inside my body.
So if my visceral fat is all saturated fat, which is as a result of what I'm eating,
then actually that's bad for my health.
If I start eating olive oil and avocados and things like that,
I could replace that visceral fat now with that avocado and olive oil fat.
That's actually going to be healthier for me.
Yeah.
I do want to emphasize the point that adipus tissue,
this organ is made of loss of components,
and liver fat and pancreas fat and muscle fat
are as important as visceral fat when it comes to health.
But they all get affected the same way when you do intervention.
Yeah. So let's talk about the intervention. So the intervention you don't want to do is yo-yo dieting. Because although you'll lose some weight, then when you bounce back, actually what happens is you've lost muscle and you put on more fat. And so if you keep doing yo-yo dieting, you actually end up with much worse body composition. And similarly, as you think about this g-lp-1s, you will lose visceral fat as you lose weight. But if you bounce back, you're going to be in a worse place. And even as you've come down, like you've
probably lost muscle, so you've really got to be aware of that. On the positive side,
like the thing that can really make a difference here beyond the food that you eat is physical
activity. And all exercise is good. You talked about the fact like, you know, if you don't go
for a walk, go for a walk. If you go for a walk now, so at the point that you're a bit breathless
as you do it, this is going to be great for your visceral fat because actually all exercise is
going to burn some fat and your body is going to sort of pull out the visceral fat first because it's
easy to get to. That's exciting. But if there's one key message from all of this, it's do resistance
training. That is the thing that is going to target that sort of visceral fat the best and with this
benefit that it builds these muscles that then has all of this sort of like counteraction
against the fat. And in your studies, you said in 12 weeks time, using this combination of improved
diet and resistance training, you can have a significant reduction in this visceral fat and
therefore an improvement in real measures of health.
Yeah.
And just think fat is your friend.
