Recap: Why you should stop counting calories | Giles Yeo

Summary

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Podcast Summary

Podcast: ZOE Science & Nutrition
Episode: Recap: Why you should stop counting calories | Giles Yeo
Date: December 23, 2025
Host: Jonathan Wolf
Guest: Dr. Giles Yeo, Biologist

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Main Theme

This episode challenges the widely held belief that losing weight is simply about "calories in versus calories out." Dr. Giles Yeo explains why counting calories is an oversimplification of nutrition and weight management, highlighting the complexities of appetite, biology, food quality, and human behavior. The conversation aims to help listeners rethink their approach to dieting and understand why focusing solely on calories is not the answer to sustainable health and weight loss.

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Key Discussion Points & Insights

1. Why Calorie Counting Dominates Diet Culture

• Calorie counting has become central to how people understand dieting: “Eat fewer, burn more, lose weight. Simple, right? Except it's not that simple.” ([00:01])
• The assumption is that consuming just one calorie more than recommended will result in weight gain, leading to an overemphasis on the calorie number as the sole determinant of weight.
• Memorable Quote:
  • Host: “We're living in this world where, like, counting calories is the way that we understand what happens, and the calorie number is what determines our weight.” ([00:43])

2. The Physics and Pitfalls of Calorie Counting

• While you must be in an energy deficit to lose weight, calorie counting is overly simplistic.
• Dr. Yeo explains:
  • If you eat “half the carrots and half the steak and half the potatoes” from a balanced meal, you will lose weight because of the physics of energy balance.
  • The flaw is that calorie counting ignores nutritional quality and context: “A calorie does tell you how much food that is there, but that is all it tells you. It is completely nutrient blind.” ([01:06])
• Obsessive calorie focus can lead to poor food choices (e.g., 300 calories of chocolate versus salad). ([03:26])
• Memorable Quote:
  • Dr. Giles Yeo: “The calorie is one dimensional. Literally is one dimensional when you're referring to a meal.” ([01:54])
  • “If you're focused just on one number ... it's easier, I grant you, but I would argue that it's very, very meaningless.” ([04:24])

3. What Calories Don’t Tell You

• Counting calories doesn’t account for:
  • Fat, sugar, fiber, or salt content
  • How filling or nutritious a food is
  • How the body actually processes and extracts energy from different foods
• Notable Quote:
  • Dr. Yeo: “We eat food. We do not eat calories, okay? And depending on what we eat, our body has to work harder or less hard to extract the calories.” ([05:19])
• Certain foods (like sweet corn) provide fewer usable calories than their simple number suggests.

4. Appetite and the Complexities of Weight Regulation

• Weight management isn’t mechanically simple; human biology creates variability.
• Differences in appetite, stress responses, and eating behavior impact how people manage food intake and weight.
  • Example: Some people eat more when stressed; others lose their appetite.
  • Dr. Yeo: “My wife ... the moment she's stressed at work... she goes, I have no appetite. ... I’m a comfort eater ... my face is in a bowl of noodles.” ([07:20])
• The "energy balance" equation is real, but the why behind appetite is biological as much as psychological or cultural.
• Appetite drivers include hunger, satiety, and reward – all mediated by complex brain circuits and hormones.

5. The Science of Appetite – A Triangle Model

• Dr. Yeo describes appetite as a triangle:
  • Hunger: Physical feeling of needing food
  • Satiation/fullness: Signals to stop eating
  • Reward: How pleasurable the food is
• These aspects interact dynamically (“If you tug on one side of the triangle, the shape ... changes”). ([10:31])
• Real-life Application:
  • When very hungry, simple foods are highly rewarding; when not hungry, only highly palatable foods (dessert) are appealing.
• Memorable Exchange:
  • Host: “My son has explained that he's got a separate, you know, ice cream stomach for the last decade.” ([11:39])
  • Dr. Yeo: “Yes. And he's right.” ([11:43])

6. Dessert Stomach and Evolution

• The “dessert stomach” – desire for high-energy-density foods even after a meal – is explained by biology, not just culture.
  • Bear analogy: Grizzly bears, during the salmon run, eat less nutritious parts as they become full, focusing on fat-rich skin for energy ([12:24])
  • Humans similarly crave fattiest, sweetest foods after being full, an evolutionarily conserved behavior.
• Dr. Yeo: “Your dessert tummy is not a human specific thing. It is a conserved behavior ... you're looking for something high in fat and high in sugar so that you can continue stuffing food into all the nooks and crannies even after you’ve eaten 2000 calories.” ([14:43])

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Notable Quotes & Memorable Moments

• Dr. Giles Yeo (on calorie counting):

  • “The calorie is one dimensional. ... It is completely nutrient blind. ... The calories are completely useless.” ([01:54], [04:44])

• On real food vs calorie math:

  • “We eat food. We do not eat calories.” ([05:19])

• Appetite and stress:

  • “[When stressed] my face is in a bowl of noodles... my wife ... goes, I have no appetite. ... That is just one behavior. And the world is split into those who eat after stress and those who don't.” ([07:20])

• On “dessert stomach”:

  • “The dessert stomach is this integrated concept where the fuller you are, the more rewarding the food has to be.” ([11:55])
  • “[Grizzly bears] only eat the skin of the salmon and the fat underneath ... because this is ... the densest part of the fish.” ([12:24])

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Segments & Timestamps

• Introduction to calorie counting & guest (Giles Yeo): [00:01]
• Problems with the calorie counting paradigm: [01:06] – [03:26]
• Why calorie counting is often meaningless in real life: [03:26] – [05:02]
• Explanation of why calories alone don’t capture health or nutrition: [05:10] – [05:59]
• Complexity of weight regulation & individual variability: [06:52] – [09:07]
• Personal examples of stress-eating vs appetite loss: [09:07] – [09:32]
• Science of appetite (triangle model): [10:12] – [11:55]
• The “dessert stomach” and evolutionary biology: [11:55] – [14:52]

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Takeaway Messages

• Calorie counting ignores food quality, nutrition, and the reality of how human metabolism works.
• Real success in weight management comes from eating better food and understanding your own biological and psychological drivers, not mindless math.
• Appetite is a product of hunger, fullness, and the pleasure of eating—these are influenced by genes, hormones, stress, habits, and more.
• The urge for dessert—or high-calorie foods when full—is not a personal flaw, but a deeply wired, universal trait across animals, shaped by evolution.

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Listen For

• Giles Yeo’s “we eat food, not calories” mantra ([05:19])
• The bear and salmon story as a metaphor for why we reach for dessert ([12:18])
• The triangle model of appetite—a simple way to understand why “just eat less” isn’t the full picture ([10:12])

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This summary captures the spirit, depth, and practical implications of the episode—empowering listeners to think critically about calories, diet advice, and their own eating behaviors.

Transcript

[A]

Hello and welcome to Zoe Recap, where each week we find the best bits from one of our podcast episodes to help you improve your health. Calories. They've been at the heart of dieting advice for decades. Eat fewer, burn more, lose weight. Simple, right? Except it's not that simple. Calories only tell us a fraction of the story. To really understand what's going on, we need to take a step back and.

[B]

Look at the bigger picture.

[A]

Helping us take this step is biologist Giles Yeo. He'll explain why obsessing over the numbers doesn't work and how we can change the way we approach weight loss.

[B]

Everybody knows that you need to count your calories. There's a certain number of calories that you're supposed to eat, and as long as you eat less than that, you'll lose weight. And if you eat, like, one calorie more than that, you'll put on weight. And we're living in this world where, like, counting calories is the way that we understand what happens, and the calorie number is what determines our weight.

[C]

It's not correct. If you deal with it the way we do today, in order to lose weight, you need to eat less. Let's just. If you want to debunk anything, because that's got to be true, okay, you need an energy deficit in your food if you want to lose weight. And there is no if, ands, and buts about that, because it's a function of physics. So in other words, if you now have a meal, let's call it a balanced meal, whatever you might actually look at. And if you then suddenly took that meal and says, well, instead of eating all of it, I'm gonna eat two thirds of it or half of it in a balanced way in which I'm gonna halve the carrots and half the steak and half the potatoes and actually eat that, then ultimately, yes, you will lose weight. So if you calorie count in a perfectly balanced way. Way. Yeah, you, you, you. You can actually. You can, and you will lose weight. The issue is that is not the way life functions, and people begin to sort of take it to extremes and sort of worship the calorie and use the calorie as the only piece of information there. Because ultimately, I think in order to lose weight, you need to continue eating a balanced diet, but eat less of it. The problem with calorie counting is it takes away the nuance of it, and you start to just count the calorie. And a calorie does tell you how much food that Is there, But that is all it tells you. It is completely nutrient blind. It doesn't tell you how much fat is in there. It doesn't tell you about sugar content, about fiber, about salt, about anything. Anything about that either makes the food taste good or bad or is good for you or not so good for you. The calorie cannot tell you any of that information. So I think we need to. I guess my point here is that the calorie is one dimensional. Literally is one dimensional when you're referring to a meal.

[B]

What's the reality that happens then for people who are following calorie counting? Because I think, again, a lot of people are listening to that. Well, surely if you do follow calorie counting, then you will lose weight. And you know, the only reason it doesn't work is because you've got poor willpower and you can't stick with it. And therefore it's all, you know, it's all, it's all your own fault. And I've, you know, that was definitely the, what I grew up with. So does counting calories work?

[C]

I mean, so imagine if you were, if you were saying that you want some diet, whatever the diet is, and this particular diet prescribes that you only have 300 calories for lunch, just as an example. These diets exist. Now, if you therefore walk into a store because you're working or what have you, and you purely look at that, well, then in theory, you could buy 300 calories of a chocolate bar or 300 calories of a salad, or 300 calories of a ready meal or whatever, or 300 calories of soda, okay? And if you do that and think about it, well, then it does make a difference what you're eating. And the calorie counting is just a really not a very smart thing to do because you can say, well, I did have 300 calories. I just consumed it all as soda, which is slightly extreme, but not that extreme, because people do decide that that's the amount of calories I'm eating, particularly if you're putting it, plugging it into your app. And so in that sense it is not very useful because you could be having more calories, but eating something different, carrots, steak, something else compared to drinking 300 calories of a soda. And it makes a big difference. So I think because of the one dimensionality of the calorie, it is not very useful. And if you're focused just on one number and you're looking at the back and you're seeing that number Then that's all you're focused on. It's easier, I grant you, but I would argue that it's very, very meaningless. I think what we want to do is improve the quality of our food. Even as we eat less. We need to eat less, yes, but actually eat less, but probably eat better quality food. The calories are completely useless.

[B]

Number and, Giles, is this just like your opinion or is there any actual science behind what you're talking about?

[C]

There is science behind it. I mean, I didn't make this up. I didn't, you know, invent it and, you know, and called it the YO Diet or anything like that. It is true, because, okay, people say, yeah, but all calories are equal. They are. Once they're in you as a little poof of energy, poof. And I think ultimately we have to remember, okay, the mantra. Let's go with the mantra. This mantra you can say is from me. We eat food. We do not eat calories, okay? And depending on what we eat, our body has to work harder or less hard to extract the calories from the food. Sweet corn is an example where clearly we can eat 100 calories of sweet corn, but we don't absorb anywhere close to 100 calories of sweet corn. Then our body extracts the calories from the food, and depending what you eat, you can extract differing amounts of energy from. From the foods we actually eat.

[B]

So I think you're saying something that, you know, I've heard often on this, this podcast and from others, that the body weight is not as simple as just sort of calories in versus energy out. And maybe it would be if we were like some sort of simple machine, but we're not. We're human beings. Our system, you know, is a lot more complex. What are the key things to know about how our body manages weight? And I think a lot of people listening to this will be immediately thinking about appetite because, of course, there's been all of this noise in the last couple of years about these new drugs that have this amazing impact on appetite that seem to have nothing to do with calorie counting and seem to be achieving outcomes that seem sort of impossible, I would say, until a couple of years ago. So what's actually going on inside us, Giles, and how do we know that?

[C]

Let me just stress again. We do need to go into energy deficit to lose weight. And that's because it's physics. It's a function of physics. How you get there really depends on who you are. You know, clearly there is an energy balance equation and that is true. The complexity is not in the physics of it. The complexity is because that's the how. How you get to where you are. The complexity in terms of weight loss, weight maintenance is in the why. So why do some people eat more than others? For example? Or why do some people appear to be more efficient with their food in terms of burning versus storage versus how fast you would actually burn the food? Let me give you an example. Why do some people stop eating when they're stressed, like work stress or what have you, whereas other people start eating when they're stressed? So, for example, I'm a comfort eater. If I'm stressed, suddenly I'm, you know, my face is in a bowl of noodles. I don't want to back myself into a stereotype, but that's what I do. My wife, however, is someone who, the moment she's stressed at work or something like that, she goes, I have no appetite. Okay, it's literally diametrically opposite, but it's the same hormone that goes up, the stress hormone cortisol goes up. But yet we behave entirely differently. That is just one behavior. And the world is split into those who eat after stress and those who don't eat after stress. So that's an example of. Of the why, right? Other people. Why do some people appear to be hungrier than others all the time and, you know, or how come some people take more to get full? And these are not imagined behaviors. They're just. They're just not. Okay, where. Yes, clearly there are going to be cultural, sociological underpinnings about why, where, how much and what we eat, clearly. But there are also huge biological underpinnings to driving our appetite, driving what we eat, driving who we like to eat with, driving, you know, where. When all these things and all of that integrates eventually into some form of energy excess or energy deficits. And so you either gain weight or lose weight, depending on these innate drives. Myriad of different reasons about why you end up eating more or eating or eating less.

[B]

That's really interesting. I never thought about the idea that some people might be a comfort eater and some people might turn off. I think if I'm really stressed, I often want to eat less.

[A]

Actually.

[C]

Don'T even talk about food. Whereas I do eat. I'll sit there and it comforts me. And so I know, I know that I do it. And you try and organize your life so you don't do it, but sometimes you just do it.

[A]

Could you tell us a bit about the science of appetite?

[B]

Because one of the things I'm really struck with my journey with Zoe over the last eight years is that I ate a completely typical British or American diet eight years ago. And one of the interesting things, having followed my diet now for quite a few years, is that it feels as though my appetite has changed a lot and that I don't have the same level of. I don't quite know how to even describe it. Like sudden hunger bursts in the same way. But what's going on there, Giles?

[C]

So appetite is an interesting term because it's actually quite a. We sort of understand it, we talk about appetite, but it's actually quite a complex concept because it's an integrated concept. What do I mean by this? In my head, I simplify appetite into sort of a triangle, okay? Of which there are three points. One is hunger. So how hungry do you feel? I think we understand what that means. One is how full are you? Now, that is not the same thing. Okay. How hungry are you and how full you are? Are different circuits within the brain and the reward elements of food. How nice or lovely does the food taste to you? Okay, now, those three all speak to each other. They're not mutually exclusive and they involve different parts of the brain. And if you tug on one side of the triangle, the shape of the triangle changes. Correct. And so, in other words, if you are more hungry, for example, you're going to take more food to get filled up. And if you're more hungry, the food has to be less rewarding for you to enjoy the food. If you're really, really, really starving. You. A bit of bread, a bit of cheese, a bit of rice, okay? It's like the simplest foods are the best. If you are not hungry, suddenly the rewarding element of the food has to be really, really big for you to continue eating. It is the concept of the dessert tummy, where. Why after a full meal, you're never gonna order another steak after a meal, or whatever it is you're eating, but chocolate comes and you eat it.

[B]

My son has explained that he's got a separate, you know, ice cream stomach for the last decade.

[C]

Yes. And he's right.

[B]

He's right.

[C]

He is right.

[B]

Where is it in. He thinks it's in his legs. Or at least when he was 6, he did. I think now, I mean, he's 16. I think he probably doesn't. Where is his dessert stomach and how does that work?

[C]

So the dessert stomach is this integrated concept where the fuller you are, okay, the more rewarding the food has to be. So let me give you an Example from an evolutionary perspective. Okay, Take the grizzly bear. Okay. Pacific Northwest, you know, Oregon, Washington area. Hitting the salmon run, preparing for hibernation.

[B]

And Giles, just be clear. The salmon run isn't like a running race or a ski race. The salmon run is, is when the.

[C]

Salmon are swimming up the river in order to this morning, they're spawning grounds. And the grizzlies know this. And so they kind of park themselves in between the spawning ground and where the salmon are coming and eat the salmon. At the beginning of the salmon run, the bear eats the whole salmon down to the bone. Okay. Just eats it. And you can see it is just a whole pile of bones. Okay. But as the bear gets fuller and fuller and fatter and fatter because he's trying to gain fat, the bear only eats the skin of the salmon and the fat underneath the skin of the salmon. Why? Because this is calorically wise. Calorie wise or even though they don't count, it's the densest part of the fish. And you can do this. And this is what the bear does because he is trying to make sure that he can continue stuffing. He or she is trying to continue to stuff as many calories into his body as possible, even when he's now completely full of.

[B]

So he's like eating the really fatty bits. Cause that doesn't take up as much space. Exactly. With the calories you were talking about before. Exactly. So it's like bear chocolate.

[C]

It's bare chocolate. Now clearly desserts are a human specific cultural underpinning. So the bear is not having dessert. But this concept of which the fuller we become, the more dense the food we want to eat before we actually will bother doing it before it tickles. The reward parts of it is a conserved thing. So this is not a human. Your dessert tummy is not a human specific thing. It is a conserved behavior. So it's got to be high in energy density. Okay. And so what are foods that are naturally. So in other words, that for every given gram of food you eat, you get more energy in it. So what are those? Those are going to be foods that are high in sugar free sugars or high in fat. And what are foods that are high in sugar and fat? Their desserts. And so that primarily is, is the big driver. So fatty foods or sugary foods, you know, 50,000 years ago on the, on the savannah, you know, you know, we're not going to be eating a tart or Citron and a Muscat, but it might be honey, it could be really ripe fruit. It could be making sure you eat the fat bit of the, you know, of your steak or bison or venison or whatever it is you're actually eating today. It's a tart au citron, okay? But the whole thing is you're looking for something high in fat and high in sugar so that you can continue stuffing food into all the nooks and crannies even after you've eaten 2000 calories worth of venison.

[A]

As you can imagine hosting this podcast, running Zoe, juggling family life. It all keeps me pretty busy. So I try as best I can to stay energized and show up well in all those parts of my life by fueling my body with the right food, by exercising, and by adding a scoop of daily 30 to my meals every day. If you haven't heard of Daily 30 yet, it's the gut supplement designed by our gut health scientists here at Zoe. It's made of over 30 high quality hand picked plants, including seaweed, fungi and different types of fiber. Better yet, it contains ingredients that support gut health, digestion and energy, which is ideal for packed calendars and busy lives. Simply add one scoop a day to any meal for an extra boost of fiber and plant diversity. And because it tastes delicious on just about anything and adds a satisfying crunch, it quite quickly slots into your life, becoming a daily healthy habit you'll always have time for. By the way, whenever we talk about Daily 30 as a good source of fiber, we're required to say that it contains 4 grams of total fat per serving. Obviously, that's all amazing healthy fats from plants, so order yours [e-mail] Daily30 thanks for listening and see you next time.