View show notes here: https://bit.ly/3YrLl41 Become a member to receive exclusive content: https://peterattiamd.com/subscribe/ Sign up to receive Peter's email newsletter: https://peterattiamd.com/newsletter/ Eric Ravussin is a world-renowned expert on obesity, metabolism, and aging whose pioneering research has shaped much of what we understand today about energy balance and caloric restriction. In this episode, Eric shares insights from his cutting-edge work on energy expenditure—a critical factor in understanding how our bodies regulate weight and appetite. He discusses methods for measuring energy output, energy balance, food intake, and appetite regulation, and explores key studies on macronutrient manipulation. Eric then delves into the CALERIE study on caloric restriction, highlighting insights related to biomarkers of both primary and secondary aging. The conversation also covers the potential of GLP-1 agonists to replicate these effects and looks ahead to how AI and technology could transform metabolic research in the coming years. We discuss: 0:00:00 - Intro 0:01:34 - Eric’s background and current work metabolism and measuring energy expenditure 0:07:18 - The science behind metabolic chambers for measuring energy expenditure, and the complexities of indirect and direct calorimetry 0:17:47 - The body's regulatory systems for maintaining energy balance and the primary influence of energy intake on body weight 0:25:00 - The epidemic of obesity and a discussion of resting metabolic rate 0:29:15 -The impact of exercise, appetite, gut hormones, and eating patterns on weight regulation 0:40:11 - Experiments looking at how macronutrient composition affects energy expenditure 0:54:05 - The challenges of studying diet in real-life settings, the potential of personalized nutrition, and how public health policy could play a role in guiding nutritional habits 1:13:27 - The importance of protein in the diet, the limitations of dietary data collection, and how AI could potentially transform nutrition science 1:21:30 - How Eric’s interest in caloric restriction (CR) began with Biosphere 2, metabolic efficiency's role in aging, and goals of the CALERIE study 1:35:20 - The CALERIE study: exploring the real-world impact of caloric restriction 1:49:16 - Notable findings from the CALERIE study after two years: sustained weight loss, participant retention, and more 1:57:21 - The effect of caloric restriction on the hallmarks of aging 2:07:07 - The challenge of applying CR to the general population, the potential of drugs and exercise to mimic the effects of CR 2:15:08 - Upcoming study comparing caloric restriction to time-restricting eating, and Peter’s takeaways from the discussion -------- About: The Peter Attia Drive is a deep-dive podcast focusing on maximizing longevity, and all that goes into that from physical to cognitive to emotional health. With over 90 million episodes downloaded, it features topics including exercise, nutritional biochemistry, cardiovascular disease, Alzheimer’s disease, cancer, mental health, and much more. Peter Attia is the founder of Early Medical, a medical practice that applies the principles of Medicine 3.0 to patients with the goal of lengthening their lifespan and simultaneously improving their healthspan. Learn more: https://peterattiamd.com Connect with Peter on: Facebook: http://bit.ly/PeterAttiaMDFB Twitter: http://bit.ly/PeterAttiaMDTW Instagram: http://bit.ly/PeterAttiaMDIG Subscribe to The Drive: Apple Podcast: http://bit.ly/TheDriveApplePodcasts Overcast: http://bit.ly/TheDriveOvercast Spotify: http://bit.ly/TheDriveSpotify Google Podcasts: http://bit.ly/TheDriveGoogle Disclaimer: This podcast is for general informational purposes only and does not constitute the practice of medicine, nursing, or other professional healthcare services, including the giving of medical advice. No doctor-patient relationship is formed. The use of this information and the materials linked to this podcast is at the user's own risk. The content on this podcast is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Users should not disregard or delay in obtaining medical advice for any medical condition they have, and they should seek the assistance of their healthcare professionals for any such conditions. I take conflicts of interest very seriously. For all of my disclosures and the companies I invest in or advise, please visit my website where I keep an up-to-date and active list of such companies. For a full list of our registered and unregistered trademarks, trade names, and service marks, please review our Terms of Use: https://peterattiamd.com/terms-of-use/