Dr. Jason Fung Explains Why You Are Always Hungry

This big lie that we get sold is that you just have to eat fewer calories. If you can't, it's your fault. You didn't have willpower or you didn't have discipline. And it's not true. You don't get to choose if you're hungry. You can choose what to eat, but you can't choose to be hungry or not hungry, right? Perimenopause period is actually one of the highest risk periods of weight gain for women. It's so clear that it's a hormonal issue. And as you talk to them, you realize They're doing exactly the same things that they've always done. They're eating the same things they always did. Obviously, it's hormones.

This might be too extreme, but do you think we're being biologically manipulated here?

With ultra-processed foods, absolutely.

This individual-sized bottle has no more calories than half a grapefruit.

Right after you eat those Cheetos and have your, you know, frappuccino, 10 minutes later, you're still ravenously hungry. The body's response to those same 2-calorie portions was completely and utterly different.

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Thanks. Thanks. Good to see you, JJ.

Oh, it's always fun to have you. And I am such a huge fan of your work. So I love this new book, The Hunger Code, and I'd love to just jump in and ask you what the biggest lie has been that we've been told about hunger?

Well, I think that the biggest lie really is just because you haven't eaten in a while, or hunger is because your body needs nutrients or something like that. And it's not actually true. Like, there's lots of different types of hunger. And the reason focusing in on the hunger is important is because that's sort of the reason why we eat, right? So you eat because you're hungry and you stop eating when you're full. So obviously, if you're really, you know, trying to change eating behavior, you have to understand what is causing the hunger in the first place? And people think, well, you know, either it's, people think, oh, it's just because you haven't eaten in a while, or it's because your body demands nutrients. And I hear this from nutritionists all the time, and it's quite strange because it's like, if you think about it, if you have somebody who's overweight, say they have 50 pounds of fat, well, clearly that's a store of calories, right? So they have thousands and thousands and thousands of calories that they have in excess. Not in deficit. So the question is, why are they hungry, right? And that's where it's really important to understand that there's actually not one type of hunger. There's actually multiple types of hunger which drive the reason we eat. And so the physical hunger that we think about, which is, you know, your stomach is growling and all this sort of thing, it's called homeostatic hunger. And that's driven mostly by hormones. And we see this in, for example, uh, the weight loss drugs, the GLP-1s or things like Ozempic, which use the GLP-1 hormonal system to sort of squash hunger. It's one of the satiety hormone. So it tells you that even if you haven't eaten in a while, if you activate these hormones, you won't be hungry. So it's really a hormonal issue, but that's actually not the main reason that most people eat. There's actually two other main types of hunger other than this physical hunger, which is called homeostatic hunger. A lot of people eat because it's pleasurable or it makes them feel good or it makes them feel bad. And that's this sort of emotional hunger. And the technical term is hedonic hunger. And what it means is that if you have somebody who's upset, say they broke up with their boyfriend or girlfriend, right? And they eat, they eat comfort foods, right? Because it makes them feel better. Right? So they're not eating for physical hunger. They're eating for this sort of emotional hunger. And it's the same if you're eating for, because you're bored or if you're eating because, you know, you just want to, like dessert, for example, you don't eat dessert because of the physical hunger, cuz you just ate. You're eating because of that sort of pleasure. And we know that food is pleasurable. It sets off, uh, you know, reward, uh, pathways in the brain, dopamine and all this sort of stuff. Right. But it can actually go in excess. And that's where ultra-processed foods, you know, really start to become a problem. And that's because they can turn up that sort of reward system to sort of maximum while minimizing the sort of physical satiety. That actually drives a lot of the reasons that people eat these days. It's because, you know, for this sort of emotional hedonic hunger. And the third main type of hunger is this sort of conditioned hunger, which is the sort of habit, this sort of habitual thing that is you eat because you always eat, right? It's breakfast time, so you eat. It's coffee, so you eat. Like all these sort of things become intertwined with eating. And therefore, when you go to see a movie, for example, now you create a lot of hunger because you always eat during that time. And that's what drives a lot of people to eat. They're not actually hungry. It's just like if you go to a meeting, for example, at work, and somebody always, you know, orders cookies, for example. Now you want cookies every time you go to a meeting, right? But that's not because you actually need it. You don't— your body is not crying out for nutrients, right? And there's no nutrients in those cookies anyway, right? But the point is that you're creating that hunger, and that hunger is going to drive you eating behavior, which is going to cause you to eat more. So really understanding sort of the root cause of the hunger is so important, and it actually goes far beyond just the diet, because a lot of these things, the emotional side of things and the social side of things are actually what's, what's at play here. And you see this because, you know, different countries, for example, have different, you know, social mores and so on. So therefore they have actually different rules around eating and some of which keep them very slender, even though they have access to the same foods that we have.

When you look at this model, and I've been listening to a lot of your interviews, looking through the book, It really flies in the face of the, you know, just stop eating so much, just calories in, calories out. Was there a patient— like, what made you start to realize how broken this model we currently are using is?

It was really because of the spectacular failure of the sort of eat less model, because it's what we all grew up on. You know, everybody in medical school, everybody who was a dietitian, we all got taught this. You're gaining weight because you're eating too many calories, therefore eat eat less calories. But the more you think about it, the less useful this advice actually is. Because if you think about it, you could draw an analogy, for example. Suppose somebody is an alcoholic, and so alcoholism equals alcohol in minus alcohol out. Well, there's no denying that, right? If you drink more than you can metabolize, you're gonna get drunk, right? Well, is the solution just drink less alcohol? Like, has that ever helped an alcoholic? No, absolutely not, because you never— understood the deeper reason behind the alcoholism. That is, suppose somebody is depressed and that's why they're drinking alcohol. Now you need to deal with the depression. Suppose they're lonely and they're drinking alcohol. Now you have to deal with the loneliness, not just tell them drink less alcohol. If you think about something such as the 12 Steps, right? They talk about forgiveness and spirituality and making amends and all these sorts of things. The one advice they don't have is drink less alcohol. Right? And they're very, very successful. So if you think about eating in that same vein, this idea that you can simply tell somebody, "Eat fewer calories," it's crazy to think that it would work because you never understood why they were eating too many calories in the first place, right? Was it emotional eating? Was it food addiction? Was it ultra-processed foods? Was it lack of sleep, for example? And there's this idea, you know, and I don't know why I think about these people who talk about calories in, calories out, you know, a calorie's a calorie, all these sort of calorie bullies, right? And it's like—

Calorie bullies. I love that.

It's so crazy because the story that we get sold, this big lie that we get sold, is that you just have to eat fewer calories. If you can't, it's your fault. You didn't have willpower or you didn't have discipline. And it's not true because the reason you're eating is because you're hungry. You don't get to choose if you're hungry, right? That's not a choice. You can choose what to eat, but you can't choose to be hungry or not hungry, right? So this whole idea breaks down. So just like, you know, there, there's lots of different causes of alcoholism, right? There's the depression and PTSD and, you know, loneliness and social isolation, all these sort of things that can lead you to drink more alcohol. Just the same, a lot of things can lead you to overeat, But the solution is not eat fewer calories. And it's very clear, for example, for, you know, that it can be a hormonal issue. It can also be things like, you know, if somebody's not getting enough sleep, if you don't get enough sleep, then the solution obviously is get more sleep, not eat fewer calories. So it's like, how does this eat fewer calories actually work? Right? It doesn't work because you never actually looked at the problem. You just sort of papered it over with this superficial don't drink alcohol sort of solution. Or if the problem is you're eating too many ultra-processed foods or too much sugar, for example, too much junk food. Well, the solution is to eat less junk food, not eat fewer calories, right? Eat fewer calories means I can eat my junk food and not eat my beef and, you know, salad and vegetables because I decided to eat cookies and ice cream instead, but it's the same calories, right? So this whole idea that eat fewer calories is the solution to everything is ridiculously stupid, right? But it's everywhere. It's so everywhere. It's It's insane to think that anybody would even believe it in the first place. There's not just the physical side of things. There's the emotional side of things and the social side of things, all of which are important. You know, the perimenopause period is actually one of the highest risk periods of weight gain for women. It's so clear that it's a hormonal issue, right? So if weight gain is all about willpower and discipline, how is it that every single woman in the world at exactly the same time in her life loses discipline or willpower and gains 5 to 10 pounds even. And as you talk to them, you realize they're doing exactly the same things that they've always done. They're eating the same things they always did. They have the same amount of willpower and the same amount of discipline as they always have. Why are they gaining weight? Obviously it's hormones. So how does that calories model work? It doesn't. It doesn't work in the least. It's because of the change in hormones. So this whole idea that it's all willpower, discipline, calories is such a ridiculous idea. Like, it just doesn't hold in any sort of capacity. And yet it's sort of the—

it's still going on though. Yes. We need to ask you, like, since it's still going on and it's so obvious our bodies are chemistry labs here, not, not just a bank account, and that really you have to get to the root cause, which is what you've been doing through throughout your books. Since the discipline thing still keeps going out there, who is benefiting from this? Because it keeps getting pushed out.

It's a twofold thing. I think on the one hand, you have this, you know, sort of inertia, right? So it's always how a lot of people in authority have always sort of put weight gain as this sort of accounting of calories in, calories out, even though it's actually not true in the least, right? And so therefore, people who have made their careers and written their PhD thesis based these and all this sort of stuff on calories, calories, calories, of course they want to perpetuate it. So there's this sort of inertia. And then there's this whole bro science culture, which is these people who like to work out, they're also relatively lean, right? And then they like to use it as evidence of their moral superiority. Like, look, I have willpower and discipline because I'm so skinny and you're not. You know what? That's what perpetuates it, right? All these people who are basically trying to convince people who have weight to lose that it's their— it's just a discipline and willpower problem, and therefore they will fix it, but also so that they can basically preen in front of everybody and say, "Look, not only am I lean, but this is evidence of my moral superiority over you, who is not lean." It's this sort of self-congratulations.

The reality is, though, if you— if we had a bunch of willpower, we wouldn't be here as a people group. Like we're hardwired to seek these things out. I mean, what you've just basically said is this, we have to stop looking at this as some kind of character flaw and look at this as a biology problem and really a biology problem that's been amplified over the last 50 years with some big shifts in, in food. So I'd love to get into that. Like what's changed over the last 50 years, especially even the last 20 to 30. Yeah.

I think the biggest thing, and I think this is where a lot of the research has really gone in the last little bit. Is the sort of rise of the ultra-processed food. So first, the obesity epidemic started sort of in the '70s, late '70s, right, with the dietary guidelines, and then 1980 with the sort of those guidelines. And of course, at the time, the guidelines were eat a lot less fat, so, and eat a lot more carbohydrates, right? Because if you ate rice, for example, you could eat it without any fat, or, you know, all the carb-loading days.

I remember it first time I've been hypoglycemic in my life was the low Low fat days.

Yeah, it was a good, you know, sort of almost 2 decades, right? All the '80s and the '90s. And I lived through it too, right? There was a lot of low fat, low fat, low fat. Yeah, it's like, because you could cut calories easily by cutting out fat because fat is the most, uh, calorie dense.

You're hungry all the time.

That was the problem, right? And it's like, did nobody see the problem? If you simply cut all the calories, you had fewer calories, but your hunger was way up. And that would eventually break you because it just didn't take. On the other hand, if you, if you reduce the hunger, you also ate less because, but now you're not fighting yourself anymore. The thing that happened in the '70s, so people, they said, hey, eat more carbs, eat less fat. And then the, the side effect of that was that there was this idea that processing food was good because you could now take a food and then process the fat out of it. Right. So you could get low-fat this, low-fat that, right? Because you could process it. So instead of, you know, eating sort of natural foods, people came to see processed foods as a boon. Basically, it was the margarine instead of the butter sort of idea, right? We can create this fake fat that is better for you than real fat, like butter. Terrible conceit that we could think that we're smarter than Mother Nature, right? But nevertheless, that's what happens. So eventually, our— the diet of the Western nations particularly became replaced with ultra-processed foods. And the problem is that the processing does a lot of different things, but really it cuts across all the different types of hunger. Not only does it spike insulin and decreases a lot of the satiety hormones like GLP-1 and GIP and that kind of thing, the processing changed all that. But then they also created a lot of this hedonic hunger. That is, you could take a food, you could take an, you know, a natural food can only exist in a certain number of ways. But if you take an artificial food, you could change it in any way. And, and so if you maximize the sort of rewarding effect of that food, you do it by having focus groups and seeing what the best, you know, maximum amount of salt and sugar and fat and what the bliss point is, and add the artificial sweeteners and artificial colors and artificial, you know, uh, enhancers like texturizers, emulsifiers, to get the perfect sort of thing. And then you get these ultra-processed foods. So they're creating not just the sort of homeostatic hunger, but the hedonic hunger. And then because they're easy, it's easy to, you know, push them into the sort of mainstream. Because if you're sitting down to watch a movie or something, it's easy to grab a bag of chips, but not so easy to go boil yourself an egg or fry 2 eggs. Right. So natural foods are at a huge disadvantage. So the conditioned hunger, the hedonic hunger, The homeostatic hunger was driven way up by all these. And you see this because in North America, of course, ultra-processed foods makes up the majority of our diet, right? 60 to 70% sort of thing. Whereas other places in the world like Italy or Japan, they're looking at 25, 30%. And this is the thing, like Italians love food, right? They're famous for loving food, but they're eating natural foods. And that's been the big difference, the ultra-processed foods, which cuts across all these different problems. So you see it. An Italian in Italy has a very low risk of obesity. They have one of the lowest of the developed world, right?

And yet they have pasta and bread.

Exactly. So it's not just about the food.

And there aren't gyms on every corner.

They barely— yeah, they barely have gyms actually, but they walk a lot. Right. So you see that the thing is that it's not simply the foods because you can take those foods, but it's the way that you eat. It's the, it's the processing of those foods. It's the social environment. That is, if it's, if it's acceptable, if it's expected that you eat all the time and that you eat huge portions, like, you know, uh, in the U— like in the US, then that's what you're going to do because you're influenced by what other people do. So that Italian in Italy, you know, has a very low risk of obesity, but they're eating pasta. But look, they're eating it natural foods. They're eating it at a table. They're eating it in season. And the portions are much smaller because that's just the, the, just the habit. Right now you take that Italian, plop him in New York City and his risk of obesity or her risk of obesity just skyrockets. Right. What's the difference? Not the person. The person is the same. The willpower is the same. The difference is the environment, the ultra-processed foods, which is, and the, and the social environment. Just like, for example, there's lots of studies out there, but if your best friend becomes obese, your own risk of obesity goes up by over 100%. Why? They don't sap your willpower, but it's because what they do affects what you do, right? We're, you know, we're influenced, and this is called social modeling. This— we're influenced by what other people do. So you have to stop pretending that it's all an individual problem, that it's all a dietary problem, because a lot of it is emotional and a lot of it is social. And until you realize it, you can't fix it yet. The first step to fixing it is to recognize what the problem actually is.

This might be too extreme, but do you think we're being biologically manipulated here?

With ultra-processed foods? Absolutely. And that's not deliberate or hidden, really. It's quite deliberate. And this is why it's important to understand that, hey, this is the problem. And it goes far beyond just the calories or the carbs or whatever. And a perfect example is diet sodas, for example. Diet sodas have no calories. Well, think about this. How many times has anybody ever told you, oh, I just switched to diet soda, lost 30 pounds? Never. Right. But how many times have I heard, oh, I was addicted to this stuff. I had like 10 diet sodas a day. As soon as I stopped that, I lost 30 pounds. I hear that like all the time. What? Why? There's no calories, right? The difference is that artificial food is creating that hedonic hunger. That artificial sweetness is causing you to crave more other foods. So you do. That's why you become hungry. And when you hung hungry, you eat. The actual— what was making you hungry wasn't that, didn't actually have calories. That whole, you know, ultra-processed foods is driving a lot more problems than I think that we know. And that's where in the last 5 or 6 years, the research has really started to focus in on how ultra-processed foods really are bad for you. And it gets to the core question of why are you hungry in the first place, right? So yeah, absolutely, we're being manipulated.

We have to study that these foods are bad for us. We're spending money. I'm like, why don't we just support the fruit and vegetables instead of doing this?

I hear these comments from doctors and stuff. They're like, do you have proof that this chemical is actually bad for you? I'm like, you're so crazy. The default should be you need to prove that this chemical is not bad for me before I let you eat it. Right. And the problem, of course, in the United States and you see this a lot, is that the government allows a lot of stuff in there that's banned in Europe and Canada, right? It's sort of nuts. There's a lot of these memes that had gone around about, you know, even like Froot Loops and stuff. They had all these lead-based dyes and all this stuff, all this junk in there. And it's like they didn't have it in the European version. It's like, yeah, all that stuff was banned. It's like, okay, so why do we— why do Americans allow it? Like, please tell me. And then there's always some doctor who's like, well, it's not proven harmful. It's like, I'm like, don't be such an ass.

I just listened to a podcast today, I kid you not, by a big researcher in obesity who is talking about, you know, processed foods are okay and artificial sweetener. I'm like, what am I hearing? How can I be hearing this? Let's not even talk about gut microbiome and artificial sweeteners. Just in the very fact that when you eat sweet, you want more sweet. What more do we need?

It's obvious to everybody. Like, really, it's like, do we need a study on that one?

I don't know. Have you— what about you? Like, you and hunger personally, have you struggled with hunger yourself here? Like, did you just like hack this early on and you're fine? Like, what's your story?

I mean, I have a tendency to gain weight. I think some of it is genetic because I look at my brothers and sisters and stuff, right? But I haven't actually struggled with weight that much because I actually got onto it sort of fairly early. So I did a lot of fasting, right? I wrote about fasting, how beneficial it is. So I do it.. And sometimes I do longer ones, right? Multiple days and so on. And I recognized very early on that that physical hunger is actually not what kills you during fasting. That physical hunger actually fades. What kills you is the hedonic hunger. That is the, oh, look, I'd really like to have that slice of pizza or whatever, because it looks delicious and it will get a lot of pleasure, but I'm not actually physically hungry. Right? So I was aware of that I wanted it, but I was also aware that I actually didn't need it because of course my body was, you know, fueling itself on its fat, right? So it was, you know, it had plenty of energy that it could use. So that was sort of the idea because once you start fasting, you realize how little physical hunger actually contributes to why you eat every day, right? Most people eat every day on schedule. So I've actually never felt it. That was one of the things that I always thought kind of strange. And again, I like to think about these things, uh, sort of just to understand, because it's, it's not until you sort of frame it in those ways that you understand. And then when, when you, when I dug into it, of course, there's a, there's a huge amount of literature on, you know, all these hedonic hunger, conditioned hunger, all these sorts of things. And it's like, okay, if the problem is hedonic hunger or conditioned hunger, then we need to bring completely different tools. To the fight because it's not about the diet anymore, right? It's about our social environment. It's about the environment that allows us to eat all the time. I mean, another thing I thought was always strange was like, if you think about the meetings at work, right? And I have these meetings every so often at the hospital and stuff. So a lot of times people will order a plate of bagels in the morning, or if it's an afternoon, they'll order a plate of cookies, right? The problem is this, that if you're in the middle of that meeting, Right? If you didn't have that plate of cookies or the bagels in front of you, you wouldn't eat it, right? Because nobody's gonna walk out, go get themselves a cookie, and then come back and everybody's like, where'd you go? I'm like, oh, I need a cookie, right? No, you would never do that, right? So it takes a lot of willpower to eat a cookie in that meeting. On the other hand, if the plate of cookies is right there in front of you, it takes a lot of willpower to not eat it, right? Because they're sitting there. You're bored out of your mind. Everybody's droning on and on. So you want that cookie to give yourself, not because you're hungry, but because you want to give yourself a little bit of pleasure and everybody's droning on and on, right? So it's like, okay, now think about it. The difference was not the person. I'm the same person. The difference was the physical environment that it was in. But it makes such a huge difference because everybody knows, and it's not about knowledge, everybody knows you shouldn't eat cookies. Like you don't have to be a genius, right? But it's not the knowledge that was the problem. It was the environment that was the problem, right? So therefore you have to change that physical environment that you're in to make sure that you don't do these sort of things, right? Another example I give is the coffee, right? You go to coffee, you line up, and then there's all these donuts and cookies, right? So then you get it because it looked great, right? So, well, how can you change that? Well, you can use an app, which is what I do all the time now. You order your coffee. You're not tempted by cookies because I'm not there for cookies. I'm there for coffee. Then you skip the line, get your coffee, you walk out, and that's perfect because now you've understood that, hey, the problem was the hedonic hunger. The problem is that they're tempting me with all this stuff. Cuz you know, you get there, it smells good. You get the smell of the coffee, right? The whole thing. Now you can, but you can redesign that environment so that you don't have that. Conditioned hunger or the hedonic hunger.

Is it obvious to someone? Like, I can tell if I've got physical or hedonic, or, you know, but for most people, are they aware what's going on, or is it just kind of below the surface, right? Oh, I'm hungry, it's breakfast time. They don't realize it's kind of Pavlovian.

Exactly, exactly. It's exactly Pavlovian. And that's the thing. Or, oh, I'm going to see a movie, or I'm going to watch a game, I'm going to have something to eat, right? And I think that that's where the technique of mindfulness is so important because mindfulness is about understanding why you're doing what you're doing, right? It's not about accepting it. It's not that you don't necessarily— you know, you might eat that cookie, right? But it's at least you understand why you're doing it, right? So the whole point is that if you're mindful of stuff and it does take practice, right, then you're going to understand why you're doing what you're doing.

I'm thinking because you mentioned fasting, I'd like to get into to that a bit and what it does to hunger, but it would seem like one of the ways you could unpack the different types of hunger is through fasting.

Yeah. So in the book I have sort of 3 golden rules for weight loss. One is avoiding ultra-processed foods because it's really bad on a number of—

And again, I think back to this researcher who said, I'll avoid them when I know that they're really bad for me. I'm like, I think it's really important to underscore what you just said, which is so obvious and wise. It's like, you know, prove why these things are okay and safe and good for me first, right? Yeah, yeah. Then, I mean, because anyone with any type of brain would go, oh, there is a big difference between a potato chip and a potato. Yeah, it doesn't take a rocket scientist.

Yeah, fasting is sort of one of these other things, uh, which is my second golden rule, is to make sure you fast regularly. And fasting does, again, cuts across multiple different things. So one, it does help you understand hunger in a much more profound way because you understand the physical hunger and what it is. And as you fast longer, it also reduces that hedonic hunger because, and particularly for food addictions and so on. So food addictions where you really can't stop, you know, addictions is where you, you know, it's bad for you, but once you start, you can't stop, right? So once you have a drink of alcohol, you can't stop drinking alcohol. Well, it happens for food too, right? And therefore the fasting can be very effective because it sort of removes all of that, removes all the triggers, removes all the cues, and then is very good for conditioned hunger. Because if you start getting used to having coffee without eating anything, for example, then it's just going to feel normal, right? Whereas if you always have something to eat with your coffee, then you always— if you have coffee by itself, it feels sort of naked, sort of thing, right? So the fasting is very, very beneficial.

When you say fasting though, fasting could be one meal a day, it could be a multi-day fast, it could be eating within 8 hours. What are you talking about specifically?

It can be any of those, sure. So you have to decide for yourself what the right answer is. Understand that the sort of normal fasting periods around 12 to 14 hours, right? So if you finish dinner at 7 PM and you have breakfast at like 9 AM, it's like 14 hours of fasting, right? And by setting that fasting period, what you're doing is setting yourself sort of a rule that you're not going to eat. So then if you get tempted to say, "Oh, let me just have a little bit of this," but it's like 9 'clock or 10 PM, then you're going to say, well, that's now going to run into this sort of rule that you've set for yourself. So you've got this sort of automatic trigger that's going to say, okay, well, I really probably shouldn't do this. And then you're going to try and be mindful about it. So maybe you'll do it anyway because of whatever reason, but at least you'll know and accept it, right? If you want to lose weight and 12 to 14 hours is great if you're trying to maintain weight, but if you're trying to go long—

normal eating, that was normal eating. Like 12 to 14 hours. Like, I can't believe we have to have a diet, a named diet, for, you know, normal eating. I think those are guardrails that should be always in place.

I agree. It was bizarre because when I started talking about fasting in 2015, 2016, people thought 12 hours was ridiculously long. I'm like, you know, when I grew up in the '70s, 12 to 14 hours was the normal. You didn't call it fasting, it was just life, right?

That's when you ate breakfast, lunch, and dinner. Exactly. And there really weren't snacks unless you were in nursery school and you got your little snack.

Otherwise, and then if you wanted your after-school snack, your mom said, "No, you're going to ruin your dinner." Right. And then if you want your bedtime snack, she said, "No, you should have ate more at dinner." It's like, you those were good rules, right? And it's like, uh, crazy because— and then people said, oh, it's so bad for you. And it's like, you know, so many kids got sent to bed without dinner. That was like a standard punishment, right? So now you're talking like 20 hours of fasting. Nobody died, nobody had any problems. Hopefully they learned their lesson and became a good boy or girl, right? But tons of people did it, right? And nothing happened. It wasn't bad for you in the least. Least, right? But it's actually so effective for, you know, the conditioned hunger, for the hedonic hunger and the homeostatic hunger, and really increasing the sort of mindfulness that having that, you know, the cutting the ultra-processed foods, making sure you fast. My third golden rule was basically to create the mindsets and the healthy sort of habits, which is that redesigning your physical and social structure. Because again, we're all social creatures, right? So that's why social influence is so important. Putting yourself in that good situation with the right people is obviously important. So, you know, we just sort of try to underestimate it sometimes. But those, you know, to me is the most important sort of rules. And they're, they're sort of like common sense if you kind of think about it, right? If you ask your grandmother sort of how to lose weight, she's like, don't eat junk food, don't eat all the time. And, you know, make sure you have the right habits and stuff.

Right. I think when I was growing up, Pop-Tarts and Captain Crunch had just started, but that was the extent of it.

Yeah.

And then, but the rest of it was you had regular meals. You had home-cooked meals. Yeah. And that's, and that's what everybody did. So that's how everybody was.

So yeah, we all brown bagged our lunches and everything. Right. And again, it's, it's not that, I mean, you know, when you eat out, there's, there's actually all kinds of problems because of course the companies that are selling you the food, like they're just trying to sell you good food. Right. Or tasty food. Right. They don't really care how it's made. What ingredients they use. They're trying to maximize their profits, right? Because it's a business and, you know, so they, they're going to give you whatever makes you come back, right? If it means adding a lot of sugar to the food, it's adding a lot of sugar to the food, right? So it's stuff you would never do when you're cooking it yourself. But, you know, when, when you buy the junk, when you buy the ultra-processed foods, that's, that's just what happens with it, right?

I want to dig into fasting a little bit more because I think you brought up something. I'm not— I don't love fasting. But I consider fasting more like multi-days, and I just, I'm really lean and I get hungry and mean. However, I really see this as such a great tool, like a kind of a hunger reset to get people to be aware. And I'm thinking of my buddy Stephanie Estima, I think you know her, was like, you know, most people don't know what feeling really, really feeling hungry feels like. They don't know what a physical hunger is. What does fasting actually do to physical hunger? You know, and when someone's going through this?

What happens when you do it regularly? So if you do it for the first time, it's going to be tough because you're used to eating a certain amount in a certain time. So then you're going to have those sorts of hunger, right? But what happens as you get used to it is, one, you, you get less and less hungry, right? Because you get this— you start to get this sort of metabolic flexibility. That is, your body understands that, hey, you're normally using glucose from your food. But if you're regularly fasting, it's going to be able to switch over to using your stored energy, which is body fat. So therefore, as you switch over, the hunger pangs are going to last a lot less. It's going to be a lot easier because your body is just going to simply say, "Oh, I've done this millions of times before. All I need to do is shift over and I'll take my calories from, you know, either stored glucose or body fat." And therefore, the hunger will sort of settle down, but you're also not getting the sort constant cravings that you do because of the sort of social cues and stuff. Like, oh, it's dinner time, I have to eat. It's lunchtime, I have to eat. Like, you don't have to do that. And, you know, it's like, you know, years ago I stopped eating breakfast, and this was not because of a weight issue. It's because I was going through medical school and I was always tired, so I'd prefer to sleep. So I'd sleep until I had to get up and then, you know, go. And then so I wouldn't eat breakfast, right? That was just the way it was. I did that for years and years.

Wow, you were trendy back then. You didn't even know it.

Yeah. But the thing is that once you start getting that, then I'm not hungry in the morning because I've never eaten. Once you develop that into a habit, then it's like, okay, well, this is easy because it takes no willpower for me to not eat breakfast. Like, I didn't eat breakfast this morning. It's like, what difference? It's the same as every single day. So it's not like I'm, I'm pushing myself to do it because it's just something that I've always done. And there's nothing wrong with that. Right. But the key is that once you develop those habits, You get the benefits, but you don't need the willpower, right? It's like brushing your teeth, right? You never have to think, "Oh, should I brush my teeth today?" It's like, no, you just do it because you've always done it. But the benefits continue to accrue. Some people just— it doesn't work. But some people, it makes all the difference. And again, that's okay.

It's a tool.

Yeah, it's a tool.

That's what I look at with all of these things. They are tools. It's like people approach them like a religion. This is a great tool to use. And you really gave me a different perspective on it. It's just the perspective of getting in touch as to what's an environmental trigger, what's a hedonic trigger, what's an actual true hunger. I mean, that alone, to understand that, is huge.

It winds up being much more than simply, you know, saying it's just about calories, right? That's only a narrow, narrow slice of the whole picture, right? You're not getting the whole picture because because you're not understanding why you're eating. Nobody eats or doesn't or stops eating because of calories. Nobody says, well, I only got like, you know, 1,400 calories, so I should go eat another 425. Like, nobody does that, right? You go, I'm hungry, I want to eat, or, oh, that looks so good, I want to eat, right? That's hedonic hunger. Or, oh, it's dinner time, I need to eat, right? That's conditioned hunger, right? All different types, but it's not calories. It's never calories.

Come on, Weight Watchers was based on that.

It was an artificial construct and it did work for some people, right? It's highly artificial because you're never differentiating between the reason why you're eating. You never understood why you're eating. You're just like calories. It's like, uh, you know, but just like, did you understand that you were actually eating because you were depressed? Like you were down because you lost your job and that's why you're binging on donuts and ice cream, right? Because you want to feel better.

The other crazy thing that's always struck me about calories is the way your body handles protein is entirely different than the way your body, you know, it's like, it's like, okay, the 4 calories per gram protein and the 4 calories per gram carbohydrates get into your body and are done. They, they are used completely differently and you're going to use a lot more of those calories and protein. So you can't equate them the same, obviously. So there's so much. With this that, that doesn't make sense.

I know, and that's the, that's like the first thing, right? So you eat protein, your body responds by, for example, you know, activating peptide YY, GLP-1, GIP. So you eat steak, protein, or fish, right? And you're going to get full, right? Now you eat Cheetos or something, highly refined carbohydrates with lots of artificial sweeteners, artificial flavors, I should say. Well, now there's no protein, you're going to massively stimulate insulin, which is basically going to tell your body to store all those calories as fat, which leaves no energy for the rest of your body. So right after you eat those Cheetos and have your, you know, Frappuccino, 10 minutes later, you're still ravenously hungry looking for that protein or whatever, right? Like, how are they the same? The body's response to those same 2-calorie portions was completely and utterly different. And you want me to pretend they're the same? Why? How is that even scientifically accurate? Like, it's completely insanely stupid. And yet that was sort of the accepted truth. It's like, to me, it's like, I can't believe people are that crazy simplistic.

So I'm going to do a couple rapid fires. Ready? Yep. Biggest myth about hunger in one sentence.

I think it's that it's just a physical hunger. I think you have to understand that a lot of hunger is both emotional and social.

Best first step for someone who feels out of control with food?

I think it's to cut out the ultra-processed foods. As soon as you switch to natural foods, our bodies know how to handle it, and therefore you're going to get a lot of that control back.

The food or the habit that most disrupts hunger signals?

Again, I think it's the refined carbohydrates. Like, it just spikes your insulin. It— the, the way it creates the hunger. It's the refined carbohydrates, and not necessarily all carbohydrates, but the refined carbohydrates are really what disrupts it. The other thing with refined foods, of course, is that all those flavors and colors and stuff wind up getting added to it, and that just sort of makes the problem worse.

One thing that someone 40+ listening— like, one thing if they started today, what would be your top recommendation?

I'd say probably to consider the fasting. I actually think that fasting has a number of other benefits other than the weight loss.

So for everybody listening, I'm going to attach— because we're not going to get into hormones today, which could be a whole nother interview, which we already did. So we did that one before when we talked about The Obesity Code. So I'll make sure I link to that as well. But for someone who wants to learn more. You've got The Hunger Code, you've got The Obesity Code, you have one more book, right?

I also talked about diabetes, The Diabetes Code and The Cancer Code. Okay.

That's right. I knew there was another one and I think we did an interview on that as well. So we'll link to everything. Um, we'll link to your website, Dr. Jason Fung. Grab The Hunger Code at Amazon, obviously, or any bookstore, cuz it is definitely one you'll want to have. And I just appreciate you taking your time with us today.

Well, thanks so much. It's a great conversation. Thanks for having me.

It always is. You're always lots of fun. And we'll put all of that at jjvirgin.com/thehungercode. Thank you again.

Thank you.