The New Science of Weight Loss (What Actually Works) | The Masterclass | EP#428

👇 Visit The Proof website for the full show notes and supporting studies. 👇 https://theproof.com/podcast/ Simon’s personal supplement stack: https://hub.theproof.com/supplements GLP-1 medications are changing the conversation around obesity, but are they really a magic bullet? In this masterclass, I bring together insights from leading experts to unpack how these medications work, who they're for, and why long-term success still depends on nutrition, exercise, and addressing the food environment. Drawing on conversations with Dr Terry Simpson, Dr Federica Amati, Dr Mauricio Gonzalez, Dr Christos Mantzoros, and Dr Stephan Guyenet, we separate hype from evidence and explore what these drugs can, and can't, do. We explore why obesity is far more complex than a question of willpower, the science behind "food noise", and why some people respond so differently to the same diet. We also dive into practical strategies for preserving muscle, improving metabolic health, and using GLP-1 medications as part of a broader, sustainable approach to health rather than a standalone solution. What We Cover What GLP-1 medications are and how they work The science of food noise, hunger, and appetite regulation Why obesity isn't simply a matter of discipline or willpower How genetics, the brain, and the food environment influence body weight Differences between semaglutide, tirzepatide, and emerging oral GLP-1 medications The importance of protein, resistance training, and preserving muscle while losing weight Why Mediterranean-style eating remains important alongside GLP-1 therapy Common side effects, dosing strategies, and who may benefit most from these medications 00:00 Why Terry Simpson Started Taking a GLP-1 04:59 What Is Food Noise, Really? 10:16 Why GLP-1 Drugs Work So Well 17:37 What Actually Causes Obesity 21:22 How GLP-1 Medications Work in the Body 25:56 The Strange Lizard Behind GLP-1 Drugs 30:26 3 Types of Hunger You Didn't Know About 38:54 How to Naturally Boost Fullness Signals 48:36 How Doctors Choose Which GLP-1 to Prescribe 56:35 Why Some People Don't Respond to GLP-1s 01:03:10 GLP-1 Side Effects, Guilt, and Eating Right 01:15:26 Mediterranean Diet's Effect on Long-Term Weight Loss 01:26:33 The Shame Around Taking GLP-1 Medications 01:39:04 Being Called a Pharma Shill 01:44:51 The History Behind GLP-1 Drugs 01:53:37 Will You Need GLP-1s Forever? This episode aims to provide a balanced, evidence-based overview of one of the biggest developments in metabolic health. Whether you're considering a GLP-1 medication yourself, treating patients, or simply trying to understand the science behind the headlines, I hope this conversation gives you the context you need to make more informed decisions. Enjoy, friends. Simon This episode is brought to you by: 38TERA Consider 38TERA's DMN prebiotic supplement a daily multivitamin for your gut. Formulated by yours truly and gastroenterologist Dr Will Bulsiewicz. Head to https://38tera.com/?ref=SIMON and use code THEPROOF for a discount at checkout. 38Tera ships to the United States, Australia, and New Zealand. Function Health Take charge of your health with advanced blood testing and personalised insights. Function Health offers a practical way to track key health markers such as cholesterol, blood sugar, and more. Learn more and join at http://functionhealth.com/simonhill for a $25 credit toward your membership. Only available to those living in the United States. Function Health ships to 48 U.S. states, excluding Rhode Island, Hawai‘i, and Puerto Rico. Eight Sleep Upgrade your sleep with the Pod 5 Ultra by Eight Sleep. Clinically validated to deliver up to 1 extra hour of quality sleep per night through temperature control and biometric tracking. Use code THEPROOF at https://www.eightsleep.com/eu/theproof/ for up to $350 off. You get 30 days to try it at home and return it if you don't love it. Eight Sleep ships to the U.S. (excluding Alaska, Hawaii, and territories), Canada, Mexico, most of the EU, the U.K., Australia, the UAE, Saudi Arabia, and Switzerland. SwimClub SwimClub is a science-backed supplement designed to support male fertility, sperm health, and reproductive wellness. Head to http://swimclub.co/theproof to get 25% off your first order with code THEPROOF. ProLon ProLon’s 5-Day Fasting Mimicking Diet is a science-backed, plant-based program designed to support metabolic health while keeping your body in a fasting-like state. Get 15% off sitewide plus a $40 bonus gift at http://ProLonLife.com/THEPROOF. ProLon ships within the United States. WHOOP Whoop, the most advanced fitness and health wearable available. Your personalised fitness and health coach to recover faster, sleep better, and train smarter. Claim your first month free on http://join.whoop.com/simon. Whoop ships to 56+ international markets, including the US, Canada, most of Europe, Australia, New Zealand, UAE, Singapore, and parts of Asia.