Metabolic Flexibility Masterclass: How Your Body Burns Fuel | EP#429

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 Most of us assume metabolic disease shows up the day we are diagnosed. In this masterclass, some of the world's leading researchers explain how the decay actually begins years, sometimes decades, earlier, deep inside your cells, and how a simple measure of lactate can reveal it long before your blood sugar ever looks abnormal. It is a genuinely different way of thinking about your health. I have pulled together conversations with Dr Iñigo San Millán, exercise physiologist and the man who coined "Zone 2" training; Professor Roy Taylor, the Newcastle researcher who reframed type 2 diabetes as reversible; Dr Kevin Hall, one of the most rigorous metabolism scientists at the NIH; nutrition researcher Dr Alan Flanagan; obesity physician Dr Robert Eckel; and endocrinologist Dr Christos Mantzoros. In this episode, we cover: Why lactate is a fuel and a signal, not a waste product, and the best window we have into mitochondrial function Whether a calorie really is a calorie, and what the tightly controlled chamber studies show The twin cycle hypothesis, and why type 2 diabetes may be simpler and more reversible than we were taught The personal fat threshold, and why a normal BMI does not always mean there is no weight to lose 00:00 The 81-Year-Old Who Reversed 30 Years of Damage 01:57 What Metabolic Health Actually Means Now 06:01 Why Mitochondria Decide Your Disease Risk 12:47 What Is Metabolic Flexibility? 15:20 Hepatic Fat Oxidation and the Sex Difference 18:29 Is a Calorie Really a Calorie? 28:41 You Can Be Sick Before You're Diagnosed 31:03 Lactate Is Not a Waste Product 36:42 Is Lactic Acid Burn a Myth? 40:34 Why Athletes Clear Lactate and You Don't 43:01 When High Lactate Predicts Death 47:13 The Study That Found Damage in Healthy People 54:31 The Lactate Test That Beats Blood Sugar 58:50 Training Zones 1 to 6 Explained by Fuel 1:09:18 Why Zone 2 Builds Mitochondria Best 1:16:50 How to Know You're in Zone 2 Without a Lab 1:23:39 Is 150 Minutes a Week Enough? 1:28:10 Why You Still Need High Intensity Training 1:31:44 What Obesity Research Got Wrong 1:35:04 The Twin Cycle Hypothesis of Type 2 Diabetes 1:42:26 Your Personal Fat Threshold Explained 1:45:45 Why Some People Store Fat Safely 1:51:29 Why BMI Fails as a Health Measure 1:55:07 Sugar or Saturated Fat: What Drives Liver Fat? 2:01:05 15kg Weight Loss and Diabetes Remission 2:04:39 Does Weight Loss Really Destroy Muscle? 2:07:05 Why Exercise Alone Doesn't Drop Weight 2:11:14 3 Tests That Reveal Your Metabolic Health 2:17:40 What Blue Zones Get Right About Movement 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. Momentous My go-to supplement brand for protein and creatine is Momentous. Use code THEPROOF for up to 35% off your first order at http://livemomentous.com. Momentous ships to many countries worldwide depending on local import regulations. Truemed Truemed helps qualified customers use pre-tax HSA or FSA dollars on health-related products like fitness, recovery, and sleep tools, often saving around 30% on average. Visit https://www.truemed.com/theproof to see what qualifies. This is hands down the best way to make the most of your health dollars. IM8 With 92 nutrients, including Vitamin B12, Iodine, Selenium and Vitamin D, in highly absorbable forms, IM8 Daily Essentials is the perfect all-in-one daily multi-vitamin to ensure you meet your daily micronutrient needs. IM8 is offering an exclusive 10% off your first order with a free welcome kit when you enter the promo code SIMON at checkout on http://im8health.com/. IM8 ships to 27 countries including the U.S., Canada, the U.K., Australia, and many regions across Europe, Asia, and South America. 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. 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.