Mind & Matter
Whether food, drugs or ideas, what you consume influences who you become. Learn directly from the best scientists & thinkers alive today about how your mind-body reacts to what you feed it.
The weekly M&M podcast features conversations with the most interesting scientists, thinkers, and technology entrepreneurs alive today.
Not medical advice.
At M&M, we are interested in trying to figure out how things work, not affirming our existing beliefs. We prefer consulting primary rather than secondary sources and independent rather than institutional voices. If we encounter uncomfortable truths or the evidence suggests unfashionable ideas may be valid, so be it.
As the host, my aim is to help you better understand how the body & mind work by curating & synthesizing information in a way that yields science-based insights that you can choose to use or disregard in your own life. Taking ownership of your health starts with taking ownership of your information diet.
I am motivated to connect the dots and distill general principles from what I learn, preferring to ask questions and play devil’s advocate to debating or incessantly pushing my own viewpoint.
My beliefs:
- Taking ownership of your health starts with taking ownership of your information diet.
- All knowledge is provisional and we must work hard to prevent ourselves from becoming attached to our favorite ideas & preferred conclusions.
- Wisdom comes from an iterative, trial-and-error process of learning and unlearning. Letting go of pre-conceived notions can be painful, but pain is information.
Sometimes modern discoveries teach us we must unlearn received wisdom. Other times, modern information overload & historical chauvinism cause us to forget ancient wisdom which stills applies. The framework for learning that I embody is inspired by three Ancient Greek maxims inscribed in the Temple of Apollo at Delphi:
- “Γνῶθι σεαυτόν” (Know thyself)
- “Μηδὲν ἄγαν” (Nothing in excess)
- “Ἐγγύα πάρα δ Ἄτα” (Certainty brings insanity)
Mind & Matter
Genetics & Neurobiology of Obesity: Hypothalamus, Leptin, Gut Hormones, Weight Loss Drugs | Giles Yeo | 222
Short Summary: The science of obesity and appetite regulation, blending genetics and neurobiology with practical insights
About the guest: Giles Yeo, PhD is a professor of molecular neuroendocrinology at the University of Cambridge. He leads a lab studying obesity and appetite regulation.
Note: Podcast episodes are fully available to paid subscribers on the M&M Substack and everyone on YouTube. Partial versions are available elsewhere. Full transcript and other information on Substack.
Episode Summary: Nick interviews Dr. Giles Yeo about the genetics and neurobiology of obesity, starting with the discovery of leptin in the obese mouse model, detailing its role in appetite regulation via the hypothalamus, and discussing GLP-1 drugs like Ozempic for weight loss. It delves into how genetic factors, like the leptin-melanocortin pathway, influence hunger, the heritability of body weight, and societal factors driving the obesity epidemic, emphasizing the interplay of biology and environment.
Key Takeaways:
- Leptin, discovered through the obese mouse, signals fat levels to the brain, but its absence causes severe obesity and infertility, as seen in rare human mutations.
- The hypothalamus, a key brain region, senses hormones like leptin and GLP-1, balancing hunger and satiety through POMC (anorexigenic) and AgRP (orexigenic) neurons.
- Body weight heritability is 40-70% at the population level, but this does not mean that 40-70% of someone’s body fat composition is due to genetic factors outside human control. Dr. Yeo unpacks how to think about it.
- GLP-1 drugs (e.g., Ozempic) mimic gut hormones to reduce appetite, offering some people 15-25% weight loss, but require long-term safety monitoring.
- According to Dr. Yeo, obesity reflects energy imbalance, but nutritional density matters more than calorie counting for health, and societal changes are needed to prevent it.
Related episode:
- M&M #132: Obesity Epidemic, Diet, Metabolism, Saturated Fat vs. PUFAs, Energy Expenditure, Weight Gain & Feedi
All episodes, show notes, transcripts, etc. at the M&M Substack
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