00:00
JJ
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.

00:08
Dr. Fung
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, I 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.

00:48
Dr. Fung
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 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, and we see this in, for example, the weight loss drugs, the GLP1s, or things like Ozempic, which use the GLP1 hormonal system to sort of squash hunger.

01:35
Dr. Fung
It’s one of the satiety hormones. 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 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 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.

02:16
Dr. Fung
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, because you just ate. You’re eating because of that sort of pleasure. And we know that food is pleasurable. It sets off, you know, reward 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, which, 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.

03:02
Dr. Fung
And the third main type of hunger is this sort of conditioned hunger, which is 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?

03:43
Dr. Fung
And there’s no nutrients in those cookies anyway, right? But. 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 at play here. And you see this because different countries, for example, have different social mores and so on. So there are 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.

04:25
JJ
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?

04:44
Dr. Fung
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 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 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 when 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.

05:37
Dr. Fung
That is, suppose somebody is depressed and that’s why they’re drinking alcohol now. You need to deal with the depression. So 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 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?

06:23
Dr. Fung
And there’s this idea, you know, and I don’t know why, like, I think about these people who talk about calories in calories out the, you know, calories, a calorie, all these sort of calorie bullies, right? And it’s like calorie bully bullies.

06:37
JJ
I love that.

06:38
Dr. Fung
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’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.

07:25
Dr. Fung
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.

08:05
Dr. Fung
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?

08:40
Dr. Fung
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 that 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 willpowered, disciplined calories is such a ridiculous idea. Like it just doesn’t hold in any sort of capacity. And yet it’s sort of the.

09:30
JJ
It’s still going on though. Which would lead me to ask you, like, since it’s still going on and it’s so obvious our bodies are chemistry labs here, not just a bank account. And that really you have to get to the root cause, which is what you’ve been doing throughout your books. Since the discipline thing still keeps going out, there is who is benefiting from this because it keeps getting pushed out.

09:52
Dr. Fung
So 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 theses and all this sort of stuff on 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?

10:38
Dr. Fung
That’s what perpetuates it, right? All these people who are basically trying to convince people who have weight to lose that it’s there. It’s just a discipline and willpower problem and therefore they will fix it, but also so that they can bas 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.

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