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

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.

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])

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])

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]

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.

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])

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.