The Livy Method Podcast - The Hunger Code with Dr. Jason Fung - Winter 2026

Episode Date: February 24, 2026

In this episode, Gina sits down with renowned nephrologist and bestselling author Dr. Jason Fung for a powerful conversation that challenges everything we’ve been taught about weight loss. Together, they unpack why the old “calories in versus calories out” model falls short and shift the focus to hormones, insulin, and how the body actually decides whether to store or burn fat. Dr. Fung shares insights from his new book, The Hunger Code, explaining the different types of hunger that drive us to eat and why sustainable weight loss has far less to do with willpower and far more to do with understanding how your body works. It’s a science-backed, myth-busting conversation that will change the way you think about food, metabolism, and long-term weight loss.Find Dr. Jason Fung:www.doctorjasonfung.com@drjasonfungThe Hunger Code: Resetting Your Body's Fat Thermostat in the Age of Ultra-Processed Food - Available March 3rd.To learn more about The Livy Method, visit livymethod.com Hosted on Acast. See acast.com/privacy for more information.

I'm Gina Livy and welcome to the Livy Method podcast. This is where you'll have access to all of the live streams for my 91 day weight loss program. With a combination of daily lives, guest expert interviews, and member stories, there is something new almost every day. Miss the morning live? Want to re-listen to one of our amazing guest experts? Well, this is the place. This podcast is hosted on ACAST, but it's available on all podcast platforms, including the one you're listening to right now, Spotify, Apple, and Amazon music. We're focusing on sustainable habits, not quick-fixing.

It's an opportunity to get curious. We're here, help people get to their health goals. One piece of time. You build and build and build. We're in for a treat today. Dr. Jason Fung is joining me. He is a nephrologist. He is also a New York Times best-selling author.

You might recognize him from his books, The Obesity Code, the Diabetes Code. To say he's one of the leading voices, challenging calories in versus calories out. I would say he's like the main voice challenging calories in versus calories out. You'd be hard pressed to find anyone else talking about this, which is why he's the perfect guest for us today. You know, calories in versus calories out conversation. It's old. It's time for a new conversation. Jason shifts the focus more to hormones, insulin, how the metabolism works. His newest book, The Hunger Code, which you all have to pick up.

You can pre-order it now. I'll give you all the information where to go. You absolutely are going to want to get a copy of this. He digs into why we eat the different types of hunger that drive us and why sustainable weight loss has a lot more to do with understanding your body than relying on willpower. Hello. Hey, Gina.

So good to see you. You know, Jason and I have had a couple opportunities to talk. And we do have some podcasts available that you can listen to as well, especially if you're interested more in the fasting side of things. So Jason and I have kind of different methods, but it's the same philosophy that it's not calories in versus calories out. I guess we start there. Why isn't it calories in versus calories out?

I think the problem with that is that it's sort of very, very sort of shallow thinking. That is calories describes the food energy, right? So that, you know, so if you eat cookies, you know, 500 calories of cookies versus eggs or something like that, they're both the same amount of energy. But your body has a choice of what to do with that energy, right? You can either store it or you can burn it, right? And they're very, very different. So let's take, you know, the energy balance equation, which is body fat, which is really just a store of calories. Body fat equals calories in minus calories out, right?

So that's true. If you simply rewrite that and you say, you know, calories in equals body fat plus calories out, right? That's the same equation. But it tells you that calories in, so what you eat, the number of calories you eat equals body fat plus calories out. So either you store it or burn it. But which one does it do? Which means that it's not simply the number of calories, but it's what you tell your body to do with those calories, right? because it's very different.

So suppose you eat, you know, 500 calories of cookies. Well, your insulin spikes way up, okay? And what does it do? Well, the insulin tells your body to store all that energy. So all 500 calories goes marching into your body fat. Now your body's like, hey, where's the energy for the rest of us, right? So then it's going to make you hungry and going to make you want to eat more. Compare that to, say, 500 calorie of omelet, for example.

Okay. Your insulin doesn't go up. So all those calories sort of stick around and it's available for your body. And then your body's like, I'm not that hungry. Why do I need to eat? I just ate, you know, a big omelet, right? So, you know, they're very, very different, even though there's the same number of calories. So if you think that there's, you know, it's just about the calories, you're, you've already lost.

Like, you're done. Like, forget it. If you think that's the end of the story, you'll never, you know, understand weight loss. So let's take two examples again. So say in the morning, you eat a three-eyed vegetable omelet, say 800 calories, right? You're full until lunch at least, right? Maybe eat until dinner, so that's pretty fake. Compare that to an 800-calorie frappuccino.

You're hungry 10 minutes later. So why would you pretend that those two things are the same, right? There's nothing the same about them. Because the minute you eat those foods, your body responds with hormones, which are instructions of what to do with that, right? It's just like, say you have a bank account, right? account is money that you save equals money in minus money out right so you can't just say well if you want to save more make more money because making more money and saving more money are fundamentally different things right if you make a lot of money but spend a lot of money you still won't save money right

it doesn't they don't translate they're different so you need to know about the calories but that's only one sort of relatively small aspect of it what you need to know is what the those foods are telling your body to do, right? When you're eating a lot of ultra-processed foods, a lot of junk foods, you know, we all know this. You eat a lot of cookies and brownies and stuff. You're going to gain weight. Why? Because you've told your body to gain weight. Your insulin is telling your body to gain weight. So that's what it is. You take the same amount of calories. You say cookie, 500 calories versus cookies versus 500 calories of an omelets or whatever that might be. Is it the insulin that is required when you when you eat the cookies that is telling your body that we need to store this

versus what happens when you just have the egg. Yeah. So if you eat the eggs, for example, your insulin doesn't go up. So it doesn't store it. So it's going to leave it for your body. At the same time, it's going to activate other hormones like GLP1, GIP, Peptide Y, Y, and these are satiety hormones. And they're going to tell your body to stop eating because you have to eat in enough.

And the thing is that that really impacts your eating behavior down the line, right? Because if you're full, then you're not going to want to eat a snack or cookies or crackers in the middle of the day, right? So the whole point is that, you know, none of this breaks any laws of physics, which all these calorie idiots sort of, you know, they obsess about this. And they're like, oh, you're breaking the laws of thermoid and eggs. Like, what are you talking about? No laws of physics are being broken. But it means that cookies are more fattening than eggs. It's like, duh, like, what were you?

I'm born under a rock. of course they're more fattening than eggs. Why are people so stuck on this? Like you say don't count calories, focus on foods that contain information helpful to weight loss, right? So why it seems very simple when you talk about it. Obviously the body's complex. Hormones absolutely matter, not just what and when you eat, but what your body chooses to do with it. Why are people so stuck on calories?

Why do they double down on that? It's been drilled into us, right? And they try to distill this complex, you know, know, physiologic behavior, which includes eating behavior, right? Because it's not about just the foods, right? It's about what our body does with that food, but it's also about all this other stuff, including, you know, how we feel and pleasure and all this stuff that, you know, the hunger code gets into. But it's been, you know, sort of drilled into us for so long that people treat it like a religion, right? It's sort of like the low fat religion of the 90s, right? Fat was going to cause

everything bad, right? And so for for a decade and a half, right? And everybody was low fat this, low fat that until we start to recognize, hey, you know, the Mediterranean diet with all the avocados and olives and fatty fish and nuts, all very high fat foods. Yeah. It's actually pretty healthy for the heart, right? And the low fat diet was, was failing miserably. So it, like, you repeat it often enough. People just believe it, right? But it's like, well, we're a lot. where's the evidence, right? We've been talking about calories and calories, calories, calories, right? A calorie is a calorie, which is like stupid, right? Of course, a calorie is a calorie, but doesn't mean that they're equally fattening. But when you keep repeating it, when every

doctor, every dietitian, every scientific paper says it's all about calories, it's all about energy balance, well, you start to believe it because it's, you know, you think that it's, it's true. But where's the study, right? Like, who has, like, where's the study that says that you just cut 500 calories and you lose weight. Every single study that does that fails miserably. Where's the, where's the people who have, you know, like, have we've all done calorie counting? How many people succeed? Like zero? Like the actual data is actually quite sobering. Like the failure rate of this sort of advice is about 99.57%, which means that if you just count calories, your success rates like 0.05% of actually maintaining a normal weight.

So that's why doctors never talk about weight loss. You know, I trained in medical school 25 years ago. No doctor ever talks about weight loss. Why? Not because we don't think it's important, but because we know that when we tell people to count their calories, they don't lose weight. It just never, ever works.

So it's like, okay, hello. Like, wake up. Like, if it works, I'd be the first one. pushing it. It doesn't work. It hasn't worked. It's been like 50 years. Like, why don't we think about something a little bit more than that, right? Because calories is like one small slice of it, right? So it's really, it's really just not enough. I mean, the entire process is very complex. So I go in the hunger code over the entire process, right? So if you think about food, it contains calories, yes. But You don't go from calories to weight gain.

It goes from the food to the digestion, the process of digestion, which makes a difference. Like how you digest the food makes a difference to absorption because you have to go from the food, which has to be absorbed into the bloodstream, which then affects your hormones, which affect your weight gain, right? And that's the whole process. And we've worked it out over, you know, 50 years of medical research. Why ignore it? Why do we just throw all that out the window and say it's all about calories, right? Do you think it's complex because like hormones especially like we know they're chemical messengers and

you know as a doctor you may find that pretty simple but you know we've had a lot of conversations to break it down in the most simplistic ways but it is complex do you think it's because it's too complex of a conversation which jason breaks down brilliantly in his new book by the way which is why you've got to grab a coffee honestly um i love the way you laid it all out but what people can lose the way they keep gaining it back they lose the way they gain it back and then they you know end up, it's pretty much impossible for them to lose their weight, set point, you call it a body fat thermostat. Do you just think it's just too complex for people to take the time to try to explain?

I don't think so. I think it's that people have sort of poo-pooed all the alternatives. Whenever you say it's more than just calories, people just sort of poo-poo it and say it's, no, no, no. It's like, well, if you want to understand the problem, like the better you understand it, the more successful you'll be at treating it, right? So the body fat thermostat's interesting because the data has been there for like at least 50 years. I was reading papers written in the early 80s that we're talking about this.

And the idea, which practically everybody who's lost weight knows, honestly, is that your body defends a certain weight. Your body wants to be a certain weight, right? And it's like your thermostat in your room, right? So you set room temperature. If it's too cold, it turns on the heat. If it's too hot, it turns on the air conditioning. either way you maintain that stable weight, the stable temperature. And your body has the same thing with how much fat it carries.

It wants to maintain it at a certain level. So the point is that how do you control this thermostat? Because if, you know, you're overweight, you know, then obviously it's not just that you ate more calories than you burn. That is true. But it's because your thermostat was set so high. And if your thermostat is set high and your body weight is below, that, it's going to make you want to regain that weight. So it's going to make you hungry. Or if it's, if you don't eat still because you're white knuckling it, then it's going to turn down

your metabolic rate until you still regain that weight. So that's what every scientific study has shown as well. You lose weight, then your metabolic rate goes down. Right. So that's a problem. So if you go into a room, for example, that's really, really hot, you don't say, let me catalog the sources of heat in versus heat. heat out, right? It's stupid. You'd say, why is the thermostat set so high, right? Same thing with your body. Why is the thermostat set so high? And it really comes down to the hormones. Some hormones push it up. Some hormones push it down. How do we know? Well, it's simple. We can experimentally just give people hormones because we have, you've done those. So if you give somebody insulin,

their weight will go up. And I don't care how much exercise you do, how much willpower you have, how educated you are, I pump you full of insulin day after day, you're going to gain weight. If you take away insulin, like type 1 diabetes, again, I don't care how much exercise you do or whatever, you're going to lose weight. Same thing with cortisol. If I give you a drug like prentizum, which is a synthetic form of cortisol, you're going to gain weight. I don't care who you are. If you take away cortisol like Addison's disease, the symptom of that is weight loss, right?

So if you push it up, you push it down, right? Same thing with OZemPEC. OZemPEC works on the GLP1 system. Well, when you push up the GLP1, your body wants to lose weight, right? Because it creates satiety. It pushes down hunger. You're going to lose weight. There's drugs like nicotine, for example, which act on the sympathetic system.

What happens when you smoke? You lose weight. That's just what happens, right? There's a whole drug called FenFenn, which also worked on the same system. system caused weight loss. The generation before that, you had amphetamines. So amphetamines are actually widely prescribed for weight loss in the 1960s. Of course, they have all of these side effects, right?

But the point is that if you affect these hormones, then you affect the weight. And that's what's pushing up and down. Same thing with perimenopause, by the way. When you lose the estrogen, your body wants to gain weight. In fact, it's the highest risk period for weight gain in women, is the perimenopausal period. And it's not just like every woman loses willpower at the same time just as their men or parents. Like, what are you stupid? Right? That's a dumb argument, right? It's because of the hormonal change. Right. I'm not saying that, you know, the jury's still out on hormonal placement there.

But the point is that it's a hormonal issue. Look at puberty. Before puberty, girls and boys have the same level of body fat. After puberty, girls have about 50% more body fat. Why? Why? Why? Because of the hormones, obviously. The testosterone makes boys gain muscle. The estrogen makes the girls gain fat in the breasts and the hips, right? It's not willpower. That's a ridiculous argument. So why do we expect that body fat percentage is all willpower and calorie counting? It's not. It's all driven by how these hormones affect you up and down, right? It's been established for so many years. So, you know, it's such a crazy, it's a crazy. It's a crazy. that we completely ignore this notion that we actually all know to be true. Like you see these people. Like we all see these people who are skinny, right? And they're eating like whatever they want. And they tell you they eat whatever they want.

Yeah. Right. And they're like skinny like a stick, right? And it's like, how are they like that? Well, it's because their body fat is, thermostat is set at that level. And when they gain weight, when they eat a lot, they actually, their hunger completely goes away. I asked one of my friends, a doctor once, and he's really skinny. And he's like, he eats whatever he wants, but as soon as he gains a few pounds, then his appetite just craters.

Like, he has no appetite until his weight sort of comes back down to that weight, which is quite, quite slender, right? And it's like, okay, that's perfect. We all know that that's the way the world works. That's the way the human body works, right? Yeah. It's actually called homeostasis. homeostasis is a fancy word to say that your body needs to maintain that stable weight. And that's why you have to adjust this thermostat. And that's why you have to think about the hormones and not the calories. Well, I love that. And you talk about all of this in your book.

But your book is called The Hunger Code because it's not just about what you eat or when you eat. It's also why you eat? So, you know, why this book? Why did you feel the need to write this book and talk? Yeah, I think it's because there's a lot of, so that's only one type of hunger. This whole hormonal thing is actually called homeostatic hunger. Yeah. And it's actually only like one third of the book.

And it's because- And that's hormones, right? That's hormones, yeah. Okay. So there's actually a lot more to it because that whole system can be basically overridden with other types of hunger. Because if you think about sort of why we eat, right? Why do you eat?

It's like because you're hungry. But the question is, why are you hungry, right? And there's that, that physical hunger, that homeostatic hunger, is only one part of it. That's not the only reason people eat. People eat because it's pleasurable. It tastes good. It looks good. And it gives you comfort, right? You feel better. And that's like comfort foods, right? Or emotional eaters, right? You get depressed people eat. So the whole thing is that that's called hedonic hunger. And it's, again, a huge well-described area because you see it all the time. You eat because you're depressed.

It's like, you know, you break up with your boyfriend, girlfriend. You eat a tub of ice cream, right? You're not eating it because you're physically hungry or dessert. You're not eating it because you're physically hungry. You're eating it to make yourself feel better. And the biggest culprit for hedonic hunger, which is this sort of emotional hunger, right? So there's the physical hunger, which is only one part of our eating of why we eat. But there's a whole emotional hunger.

And you see this in people who have had, like, trauma in their lives and stuff. Some of them gain tremendous amounts of weight, right? And until you deal with that underlying emotional trauma, you can't lose weight because that's not the reason that they're eating. They're eating because of this emotional problem. So ultra-processed foods actually is the biggest problem because they're actually engineered specifically to sort of give you maximum pleasure and minimum satiety. So if you think about ultra-processed foods, they're designed to sort of light up the reward centers in your brain.

They spike up your dopamine. They spike up your glucose. And there's tons of ways they've done it, right? They've perfected it over the years. You know, they use artificial flavors and artificial colors. And they use flavor enhancers like MSG and maltodextrins and stuff. They use, you know, emulsifiers and, you know, textur. moisturizers, like there's all the, you know, for mouth feel, you know, they talk about things like

vanishing caloric density, where if you make something very, very light, it feels like you're not eating anything. So they're designed to sort of give you maximum, you know, pleasure, right? You think about a cheese puff or something. But at the same time, not make you full, because if you get full, that's going to sort of edge out the, you know, the emotional hunger part because you're running up against the limits. So it's, it's really, One of the worst things in, you know, in weight is the ultra-processed foods. And really the data on ultra-processed foods, the research is sort of exploding, which is why a lot of people are sort of focusing in on real foods again, right?

Because it's not simply the number of calories. That was, you know, very shallow thinking. Yeah. The way the foods are processed makes a difference. Just like when you take, you know, poppies and make it processed. them, you can process them into narcotics, right? Morphine and stuff, right? There's not the poppies. Poppies are not bad, but when you process them, it can be very bad, right? You can create addictive substances. And there's actually a huge, again, huge literature on now food addictions. And again,

it's always ultra-processed foods, right? You say, what do people are addicted to? Right? I'm addicted to bread. I'm addicted to chocolate. I'm addicted to, you know, sweets, candy, whatever, right? Does anybody say, I'm addicted to broccoli? Like, I love broccoli, right? But I'm not addicted in any way to broccoli. Like, am I just, does anybody say, I'm addicted to chicken? Like, no. No. It's like, never, right? But that's the whole point. So that's the emotional hunger. But then there's actually a third type, which is a social hunger, which is called conditioned hunger. So you can actually train people to be hungry. And that's through a process called conditioning where you sort of pair two things together.

So if you have, you know, path lost dogs is sort of the classic experiment where you show dogs food or give dogs food, they get hungry. That's okay. Now you ring a bell and give them food pretty soon when you ring a bell, they'll get hungry, even though you don't give them food because you've paired the two. But again, you see the difference is that. If you think about our current environment, you know, the minute you get up, you need to eat. You need to eat something with your coffee. You need to eat lunch. You need to eat dinner.

You need to have a snack. You need to snack before bed. You need when you go in the car, you eat. In front of the TV, you eat at the movies you eat, at a sporting event, you eat. You know, when you go to the mall, you eat. So everywhere you go, every minute of the day that you're just walking around now, you get all this conditioned hunger. You're stimulating hunger. And that's the food noise.

Everybody's like, oh, I have those food noise. that's conditioned hunger, right? That's what it is. That's why you're having all this problem not eating because everywhere you go, you've been trained to have food, right? So there's a whole field of behavioral psychology that you can now bring to bear on how to negate this sort of conditioned hunger, right? And that's going to, again, it overrides you because even if you're full,

even if you had lunch, you go to the movie, it's like, oh, now you're hungry again. Why? Because of the conditioned hunger. That's the social, environmental hunger. So there's a physical component, there's an emotional component, and there's a social component, right? And that's not any different than any other problem in the world, right? There's all these different components to it. And the hunger is the same thing. What you're trying to get at is the root cause of the abnormal eating behavior that's leading to the weight gain. But it's sort of this attempt to really understand things at a much deeper level. than calories, which is the most shallow sort of thinking ever, right? It's like, it's really just symptomatic treatment, right? If, you know, if you think about it, it's a crazy idea that everything about weight loss is eat fewer calories, right? So if your problem is ultra-processed foods, then what's the solution?

Eat fewer calories? Like, but you never took care of the problem, which is the ultra-processed foods. if your problem is you're not getting enough sleep and that's why you're hungry all the time right your cortisol what's the solution eat fewer calories like no isn't the solution get better sleep right what if your problem is food addiction eat fewer calories like what are you talking about you need to deal with the food addiction right or if if your problem is emotional eating right you suffer trauma you're depressed the solution is eat fewer calories like what are you talking about you have to with the depression or the addiction, right?

It's like to the man with a hammer, every problem is a nail. And that's what these calorie people are like, right? Every single solution to this complex medical disease of obesity is eat fewer calories. Like, what are you talking about? That's the worst solution ever because it actually doesn't even think about the underlying cause, right? You can't stop, like, you know, the underlying hunger is the problem, right? you have calories and you just eat fewer calories, right? What happens?

Your hunger goes up. Well, you're going to lose because now you're fighting yourself. But what happens instead if you simply drop your hunger? Well, the calories drop as well, but you're not fighting yourself anymore. And that's the more successful solution. So that's what the hunger code is about, is about trying to understand. Like, there's different solutions. Like, it's a totally different toolkit when you're talking about hedonic hunger versus

social hunger versus homeostatic hunger. under, right? Yeah. So why would you use the same solution that all of those problems? It's insane. It's just like, oh, my God. Like, I can't believe the sort of medical literature

is at this really rudimentary kindergarten level of understanding, right? It's like, you know, a plunger is the only tool you'll ever need for every single problem in your house. Like, no. It's like, sometimes you need a screw. driver. Like, why would calorie counting be the solution for every single problem that causes hunger, right? It's an idiotic sort of thing. I honestly don't have a microphone big enough to drop, Jason. I don't have a phone big enough to drop. You know, you were just validating so many

of our members listening to us live. And I know if you're listening after the fact are just like, thank you. And this is it. And this makes sense because it's not willpower. People, we've done the calories in versus calories out. It's so much more complex than that. You have to pick up Jason's book. It's called The Hunger. I'm telling them. I've been telling them for months now that they're going to love this book. He also goes into things like how to break bad habits, managing mindset. I love your 50 tips. The first one being don't count calories and the last one being do this with a weight loss buddy or join a weight loss program. You can pick up a copy of Jason's book. You can go to his website, Dr. Jasonfung.com, because then you can get a bonus.

You can read more about him. Jason, I don't even know what to say. Thank you. Thank you so much. It's been great being here. We're going to have to have Jason back. Like I said, we've already talked to him in previous podcast. You've got to check them out. You can follow him over on Instagram at Dr. Jason Fung, also on YouTube as well, where he gives tons of tips. The world needs this book, The Hunger Code. Thank you so much. Thank you.

Thanks for everyone joining us live, all your comments and questions, and thanks for everyone listening after the fact. Have a great day. Thanks so much, Jason. The Hunger Code, get your copy today. Thanks, everyone. Thanks, Jason.