This morning I listened to a super interesting podcast published by CrossFit about why the simple ‘stay in calorie deficit - ‘calories in and calories out ‘ advice is just not enough for weight-loss goals.

1. “Starvation mode” is misunderstood

A common concern: if you fast, won’t your body go into “starvation mode,” holding on to every calorie and stalling fat loss? Dr. Fung argues that this isn’t what people usually imagine. Fasting doesn’t simply slow things to zero; rather, it shifts the hormonal environment, particularly insulin, so that the body can switch from storing energy to using stored energy.

He emphasises that calories alone don’t dictate fat gain or loss — the hormonal signals (insulin, GLP‑1 etc.) play a big role.

2. The role of hormones (insulin, GLP‑1, cortisol) in fat storage

One of the more important messages is that it’s not just about “eat less, move more.” Insulin is a major driver of fat storage; when it’s high often, the body tends to store rather than burn. Alongside insulin, Fung talks about the importance of other hormone systems — GLP‑1 (which is relevant for appetite), cortisol (stress), etc.

3. Ozempic & GLP‑1 drugs: risks, benefits, and ethical use

With GLP‑1 agonists (drugs like Ozempic) being in widespread conversation lately, Fung addresses what he sees as useful potential alongside risks. They can help with appetite suppression and improvements in glycaemic control, but they are not a panacea. Long‑term effects, misuse, ethical prescribing, cost, and resetting the underlying drivers of overeating (beyond just drug use) are themes he brings up.

4. Food addiction and ultra‑processed foods

Dr. Fung discusses how ultra‑processed foods are engineered to hijack reward pathways, making them harder to resist. This contributes to “hedonic hunger” and food addiction—when people eat not because of energy need (homeostatic hunger) but because of cravings, emotional triggers, environment, etc.

5. Types of hunger: homeostatic, hedonic, conditioned

He introduces classifications of hunger in his upcoming book The Hunger Code:

Homeostatic hunger – the physical need for energy.
Hedonic hunger – eating driven by pleasure/reward.
Conditioned hunger – habits, cues in environment (time of day, social triggers, etc.).

Understanding which kind of hunger a person is experiencing can help tailor strategies for managing eating behaviour.

6. Practical strategies: whole foods, satiety, lifestyle, community

Fung doesn’t just critique; he proposes things people can do:

Prioritise whole, minimally processed foods that satisfy (high fibre, protein, healthy fats) to reduce cravings.
Use fasting strategically to reset hormonal responses, reduce insulin exposure, etc.
Recognise the importance of environment and social support (friends, family, community) in influencing behaviour.

What Makes This Episode Valuable

It bridges academic/medical understanding (hormone biology, physiology) with real‑world diet and behaviour issues.
It doesn’t treat drugs like Ozempic as unalloyed “magic bullets”, but as tools with pros/cons.
The breakdown of hunger types gives people a more nuanced lens on why they eat when they eat, and what to do about it.

Caveats & Critical Reflections

Individual variation matters: What works hormonally (fasting, etc.) may vary hugely between people (age, sex, medical history, metabolic health). Advice must be personalised.
Fasting isn’t risk‑free: Extended fasting or intermittent fasting can have metabolic, psychological, and lifestyle downsides. It requires care (hydration, electrolytes, monitoring). Some people may find it triggers disordered eating or becomes socially difficult.
Dependence on pharmaceutical interventions: While GLP‑1 drugs are promising, long‑term safety, accessibility, side effects, and costs are real issues. Also, they often require lifestyle changes alongside to sustain benefits once the drug is reduced or stopped.
Environmental & socio‑economic constraints: A lot of the advice assumes people have access to whole foods, time to plan meals, ability to fast etc. Not everyone does.

Practical Take‑Aways to Try

If you liked this episode and want to apply its ideas, here are some actionable steps:

Track types of hunger – start noticing: when you eat, is it because you’re physically hungry, or are you responding to stress/emotion/social cue?
Choose foods for satiety – more protein, fibrous vegetables, less ultra‑processed snacks.
Experiment with modest fasting – e.g. 12‑16 hour overnight fasts, then extending gradually if it suits you (and medical background allows).
Evaluate if medication is right – If considering GLP‑1 drugs, do so under medical supervision, understand the long term plan.
Shape your environment – remove cues for overeating, get supportive people around, adjust your meal times/habits.

Final Thoughts

This episode serves as a thoughtful, balanced conversation about some of the most talked about topics in nutrition today. Dr. Fung challenges simplistic ideas (calories in vs calories out, “willpower” narratives) and argues for seeing hunger, hormones, and environment as central. For anyone interested in weight, health, or changing eating habits, there’s a lot to chew on.

Full podcast: https://youtu.be/xxKg-1DO7Ps?si=va7_ZkHtCc75-Y4t