The SECRET To Burning BODY FAT Explained! | Shawn Stevenson & Lewis Howes

In this episode of The School of Greatness, host Lewis Howes interviews nutrition expert Shawn Stevenson about why belly fat persists and how to truly burn it. The conversation begins with a personal anecdote about training and quickly shifts to a deep dive into the biology of body fat. Stevenson explains that fat is an organ composed of several distinct “communities”: subcutaneous fat (the pinchable layer under the skin), visceral fat (the dangerous depot around internal organs), intramuscular fat (marbling within muscle), and the metabolically active brown adipose tissue that is rich in mitochondria. He describes how these fat types store energy, produce hormones, and communicate with the brain, pancreas, and other organs. Two key enzymes—lipoprotein lipase (which loads triglycerides into fat cells) and hormone‑sensitive lipase (which releases them)—are regulated mainly by insulin (promotes storage) and glucagon (promotes release). Excessive sugar and refined carbohydrate intake chronically spikes insulin, leading to insulin resistance and increased visceral fat. Stevenson highlights that when fat is oxidized, about 84 % of the mass leaves the body as carbon dioxide exhaled through the lungs, with the remainder expelled via sweat, urine, and other fluids. The discussion also touches on epigenetics—how food can influence gene expression beyond DNA—and the broader impact of diet on cognition, empathy, and overall health span. Throughout, the tone remains conversational, enthusiastic, and instructional, aiming to give listeners actionable insight into how food truly controls metabolism and body composition.
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So it is that deep. This is how powerful food is. You know, it becomes everything about you. The things you see in the mirror, how you feel, it's all based on food. I think you gotta have a dream.
The School of Greatness.
Really? Yeah.
Please welcome Lewis Howes. Welcome back, everyone, to the School of Greatness. I've got my dear friend Shawn Stevenson in the house. Hello, brother. Good to see you, brother. Very excited about this. You've got a new book called Eat Smarter: Use the Power of Food to to reboot your metabolism, upgrade your brain and transform your life. And I want to jump in and ask you a question about something I've been insecure about my entire life. Belly fat. Never had a six-pack. Never. And no matter how hard I've trained as an athlete in the past, no matter how hard I tried to biohack, optimize sleep, which I did in your last book, to eating the right foods, to eating just chicken and broccoli all day, it seems like I've always got a little belly fat that I can never get rid of. I'm curious, is there a way you think I'll ever be able to burn belly fat for good through the things that I'm eating in a better way?
First of all, folks need to know that you are ridiculously masculine. You know what I mean? Like, you've got a great frame.
Yeah.
Just an incredible athlete. You know, we've done a lot of stuff together. We worked out together in St. Louis. Yeah. And-- Play basketball together. Right, man. Dude, I've got a story about that I can tell everybody. But afterwards, driving home, because we were just gonna shoot around a little bit, then we ended up playing three games and then lifting afterwards.
Yes.
And on the way home, I've never felt like that. I had to pull over and take a nap.
Really?
I've never felt like that before.
You played hard.
Because you and me were both like, no, I'm not gonna let him win. But yeah, there's a component, of course, with genetics. Now, with that said, we know that the leading science right now and what's really beginning to finally explode and become a popular part of the lexicon is epigenetics and things that are above genetic control. Now with that said, I think the first thing is having a understanding and an association with what fat actually is. And most folks have no idea. Unfortunately, we're at war with something we don't even understand. And so fat can be broken down into essentially five different categories at minimum. And a couple of these folks might have heard before, but we're gonna go even deeper. So the first type is subcutaneous fat. And subcutaneous fat is a type of white adipose tissue. This is the fat that's just below your skin. And so if you're trying to, if you think about like fat on your arms or your thighs, your butt, you can also have some subcutaneous fat on your belly, but that's the stuff you can pinch.
Now, the-- I can pinch a lot right here.
The other type of fat is visceral fat. And that's also, it's also known as omentum fat. And omentum fat is the kind of deeper recesses of your abdominal cavity, right? So this is the fat that's really kind of around the organs, you know, kind of putting, if you have a lot of visceral fat, putting stress on your pancreas and on your kidneys and just everything in your core.
This is the fat inside your, not on the outside of your muscles, but inside your body.
Yeah, so it's like your abdominal cavity.
Gotcha, your visceral fat and you want less of that.
This is the most dangerous type of fat. This is the fat that's most correlated with heart disease, with Alzheimer's, with type two diabetes. It's just putting stress on your core, everything, which there's so much around there.
Digestive tract, your organs, your liver, your stomach, everything.
And this is the stuff, it's a little bit more firm to the touch. It's a little bit harder to get your hands around. And so these are both still two types of white adipose tissue. These are storage fats. Okay, so your body's storing energy. And before I go on, let me preface by saying this. Our fat is actually amazing. It's one of the most important things that have made us the humans that we are today is our ability to store energy and to go back and utilize that energy. Our fat is programmed to do what we've taught it to do. It's just doing what it's programmed to do. It's very good at it though. And it can be a little bit clingy, you know? So you have to give the right messages, and that's part of the issue. So I just want to make that clear, and fat is also, it's not, we tend to think it's like scattered droplets of cells or unhappiness throughout our body, but it's really an organ itself.
That is an organ.
It's an organ, it's an organ that has this interconnected communication. And being that it's an organ, it produces its own hormones, all right? So it's like producing more hormones that encourage more fat storage. if it gets out of hand. Alright, so I want to preface by saying that.
Wait, is it an organ or is.
It like an organ?
It's an organ. Fat is an organ.
Yes.
And just like, for example. So fat in our body is one organ and it's all connected. From the brain to my- All connected. From the fat in my brain to.
My belly to my toe. Now there's different types of fat communities. So this is another conversation. I go through all of these. I literally call it the fat communities in Eat Smarter. and break this stuff down. So there's another type of fat in the white adipose tissue camp that a lot of people don't know about. It's called intramuscular fat. All right, intramuscular fat.
This is the third type of fat?
Yeah.
And so this type of fat really works on site to provide energy to your muscles. Now, when I went to school, my conventional education, I really was indoctrinated with an idea that fat and muscle are kind of They have this dichotomy, like they're two different things, they're separate, but they actually work together. And intramuscular fat really provides, and just to think about what it looks like, if you think about the marbling of a steak, that's your intramuscular fat. Now that can get out of hand too, and you can get what we refer to as chubby muscles, with the intramuscular fat. So that's too much white adipose tissue storage on that particular fat community. All right, so these three are white adipose tissue. These are storage fats. Now here's what's really amazing and a lot of folks might know about this next one. We also have body fat that burns fat. So they're not storage fats. These are fats that contribute to the burning of energy. The first one that's becoming a lot more recognizable is brown adipose tissue, all right, or BAT, brown adipose tissue or brown fat. Now, brown fat, the reason that it's brown is that it's so dense in mitochondria.
Mitochondria are good, right?
Yeah, mitochondria are really the energy power plants of our cells, really producing the energy. When we talk about having energy, these are the power plants creating that energy. And mitochondria is where your fat actually gets burned. So folks, we're taught these paradigms like where the how does it work? Where does the fat go? How does it get burned? Your mitochondria, actually, are the place where the triglycerides get shipped to, to actually burn them and use them as fat. So brown adipose tissue is brown because it's so dense in mitochondria.
Side note, how do I go to bed weighing a certain amount and then I wake up and I lose two pounds? Where does that go? Is that just a burn through sweat? Is that just. Mitochondria burning and it's disintegrating into the air.
What is happening? This is such a great question. So in Eat Smart, this is the first time in book form, we're walking people through how the process of fat loss actually happens. And the question should be, where the hell does fat go? Where'd it go?
Does it go to-- you- just poop it out? Do you sweat it out?
Does it-- you-'ve got that-- Do I breathe it in? You've got that Thanos keychain. Does it go to another dimension? You know what I mean? But what they did, and this was so fascinating, they actually tracked the path. of fat getting burned throughout the body and tracked how it actually is eliminated. And so what they discovered was that about 84% of the fat, because, okay, we have to preface by saying this, for us psychologically, in our culture, we tend to think of burning fat. If there's a visual of it, it's sweating.
Yeah.
Like we're at the gym, we're sweating it out. That's like, that's your fat cells crying, having a good breakup cry, you know? That's how we, that's what we think.
Yeah.
But in actuality, about 84% of the fat that you lose or that you expel from your body is through breathing.
What?
Yeah, it's eliminated via your lungs. It's carbon dioxide.
So, no way. So fat in the body and then it goes into your lungs. It's like transporting through the lung cavity and then you breathe it out?
It's an eliminatory organ. You know, we don't think about that. We tend to think about like, our gastrointestinal tract, our bladder is eliminatory organs, your lungs. And so you breathe about 84% of the fat that you lose comes out via your breath. And about a third of that happens.
While you're sleeping at night. So you breathe fat out, that's how you burn it.
Cesar Milan is the dog whisperer.
Yes, I'm just whispering.
Exactly.
I'm burning in my sleep. So wait a minute, how much fat do we burn through our our lungs.
About 84% of it.
All of our fat, so if I'm.
100 pounds, this is not just your breathing, it's all the metabolic processes that take place to create the metabolic kind of offshoots.
It just comes through the mouth.
Through the breathing. You also do eliminate some of body fat through fluids. So about, you know, somewhere around the ballpark of about 15%, 16 to 14% sweat and burp. And that's where the fat goes. Yeah, tears. All of these things are eliminating That's products. That's, you know, yeah.
Is the fat, it looks coagulated when you look at it in like in your body, right? So how does it break down and then turn into just nothing that you can see?
Yeah, it's a very complex and beautiful process.
The body is fascinating what it can do.
It is, it is. And we go through, and it can be so overwhelming, but what I did was I made it an analogy in the book of a theater, making your body like a cellular movie theater. And there are particular ushers who are there to put fat into the seats. So we tend to think that fat cells, we're trying to, quote, kill fat or burn fat, but that's not really hot works. Actually, your fat cells are storage containers and what they're getting filled with the fat cells, basically when you're, when you're born, you have a certain allotment of fat cells. All right, you can't just indiscriminately kill them. They get filled with more and more energy. It makes the fat cell expand. So what we're trying to do is to get the fat cell to let go of its contents so it can be used as fuel.
Right.
All right. And so there are two enzymes that are really the head ushers that push fats, the fat contents or triglycerides into the fat cell or they usher them out when it's time to leave. So one of its hormone sensitive lipase is the one that comes and gets folks out of the theater. All right? Lipoprotein lipase takes the triglycerides and ushers them into the theater. All right? And then there's organs that kind of dominate and regulate what those enzymes are doing. You know, namely your pancreas is like the mother of two brothers who have two different roles. One of them is insulin and the other one, its brother, is glucagon. All right? Insulin is so, man, When you think of insulin, what do you think of though?
Eating sugar.
Yeah.
That's what I think of.
Insulin spikes in the body when you eat sugar, right?
Yeah.
And most folks think of diabetes too. It's like tied into that lexicon. Of course. Insulin is so important for our survival. It's just, it's a super amazing. We need it. Yes. You absolutely have to have insulin. And if you're born, you know, in a condition where you have type 1 diabetes and the beta cells in your pancreas aren't even making insulin, like you can die, your cells won't get energy. So now here's the thing, insulin's job is to store energy.
Right?
Yeah, and to encourage all those enzymes to do their work as well. So when it's out of hand, when insulin is too active, it can be a problem.
It's storing too much fat.
Yeah, and it can get to a point where there's so much activity with insulin, it's getting overrun and stressed out that it stops doing its job properly. that's where you get insulin resistance, all right? And then you have something called this kind of instant cell fat cell creation that can take place with the liver. It'll just start making its own fat as well. So, but we'll circle back to that a little bit later. But here's the thing. So you got insulin doing its job of fat storage or energy storage. Glucagon does the opposite. It encourages your cells to let go of their contents to be used as energy. But glucagon cannot do its job unless his brother sits his ass down somewhere and stops. Insulin. Yes.
So how do you get insulin to stop doing its job?
That's what it's all about, man. That's what it's all about. But we don't want it to stop. We just want it to be efficient. Efficient. And it's, now here's another thing. We do know that as you mentioned, sugar is a big driver of insulin.
Carbohydrates in general.
Pasta's, right? Yeah, protein. But protein does as well. It incites. The activity of insulin at a lesser degree for sure. And even fat in a kind of backdoor way does drive insulin function too or even contributes to potentially insulin sensitivity or insulin resistance. So it's not just this one thing, but we do know that in our culture, you know, on average folks are eating like 150 pounds of sugar a year, you know, so that abnormal amount of exposure is chronically creating this overactivity of insulin to the point that we have insulin resistance.
Because 100 years ago we weren't eating as much sugar, I'm assuming.
Yeah, it's not even close. It's not even close.
But what is with the life expectancy increases every year? It seems like we're eating more and more bad things, but we're able to live longer, whereas before we weren't.
That's the misnomer though. We're not necessarily living longer, we're dying longer.
We're getting sicker and being able to say alive.
Yes, it's very different. And this is the first generation. We are the first generation right now that is going to not outlive our generations before us. This is the first time we're seeing this down tick. When we're supposed to be seeing folks, well, basically the life expectancy is going down for the first time in recent history. Yeah, yeah.
So, we're saying we're not supposed to outlive our parents. Or what do you mean?
So we'll just say the life expectancy of the past generation was 80 years old. Now it's 79.
Really?
So it's just going, a life expectancy is going down for the first time.
Previous generation, gotcha. It's interesting, I was asking Dr. David Sinclair about this.
I love him.
He was like, the goal is not to live as long as you can and be sick and miserable. He's like, I've seen that in too many people. The goal is to live as long as you can, healthy, flexible, abundant, not with chronic pain, and then die quickly.
Right.
To get sick and then die within a week. Not get sick and die within 20 years of misery. He's like, that's not a great life.
We don't just want lifespan, we want health span. And it all really boils down, and this is the most beautiful part about this, and what I'm really hoping to impress upon culture, because when we tend to think of food, we tend to think of it in relationship. In our culture, we think of diet in relationship to weight. It's just like what's connected. When in reality, food is one of the greatest, if not the greatest determinant of what every single cell and organ system in your body is doing at all times. And this is what I really want to get across is, of course, I'm going to give you the best information possible on the metabolism connection with food, but also how does food affect your cognitive performance. And it's shocking when you find this data out how deeply food impacts your levels of empathy and your ability to connect with other people. Break that down as well.
What are the foods that cultivate more empathy and compassion?
And what are the foods that break that down? Before we get to that, the fat storage, there was one more. Were you talking about brown fat? Yeah, brown fat. And there was another fat. Yeah, so there's one other fat. And so brown adipose tissue is very dense in mitochondria, right? So these energy power plants, that's why it's brown. Babies have a lot of brown fat. It's kind of an evolutionary adaptation advantage to prevent hypothermia, just to basically keep thermogenesis going. As you become an adult, you have a lot less brown adipose tissue. It's mostly located around your collarbones.
Your.
Shoulder blades, down your spine. And brown adipose tissue is remarkable in that it's really correlated if you have enough brown adipose tissue, which you can create more, and the mobilization activity of it is correlated with having a better body composition. So this type of fat is burning fat for you, if you know what it is. Brown fat.
Yeah.
All right, so that's, we got three storage fats and then we've got two other types of fat. And that's body fat that burns fat. Yes. And so this other one, and this is one a lot of folks might not know a lot about yet.
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