Today’s episode marks the 100th episode of STEM-Talk and the return of guest Peter Attia, who Ken and Dawn interviewed for episode one of STEM-Talk back in 2016. Peter is the founder of Attia Medical, a medical practice with offices in San Diego and New York City that focuses on the applied science of longevity. Peter emphasizes nutritional biochemistry, exercise physiology, sleep physiology, lipidology, pharmacology and four-system endocrinology to help people increase their lifespan and health span. Peter is the host of the podcast The Drive. He earned his M.D. from Stanford University and holds a B.S. in mechanical engineering and applied mathematics. Show notes: [00:04:44] Dawn opens the interview welcoming Peter back to the show. Dawn mentions that a lot has happened since she and Ken last interviewed Peter and points out that Peter is in the process of writing a book. [00:05:51] Ken asks Peter if it’s true that he does his best writing on long flights. [00:06:21] Dawn mentions that in 2014 Peter created Attia Medical, which is a practice with offices in San Diego and New York City, where he focuses on the applied science of longevity and optimal performance. Peter gives an overview of his practice and how he works to improve people’s healthspan and lifespan. [00:07:29] Ken asks Peter to explain the difference between a strategy and a tactic in the domain of optimization of performance and healthspan. [00:10:35] Dawn mentions that back on episode one of STEM-Talk that Peter talked about his eight drivers of longevity. Dawn asks Peter if his thinking over the past three years has changed in terms of the eight drivers. [00:12:30] Dawn asks what are some of the best lab tests in terms of longevity that people should request from their primary care physician. [00:14:25] Ken asks how Peter goes about determining optimal reference ranges to target in his patients, noting that the guidelines constituting normal are based on a sick overall population. [00:17:26] Dawn talks about how every year a new secret to longevity comes out with the force of hype behind it, but that rarely does the new so-called secret deliver. In contrast, she mentions how Peter encourages people to keep things simple and focus on nutrition, exercise and sleep. Peter explains how these three things can have the biggest impact on a person’s physical health. [00:19:35] Dawn explains that optimizing health span can be expensive, often costing upwards of $100,000 a year in tests and devices and off-label medications. She asks if Peter has any thoughts on if there is becoming a class divide in the world of healthspan and lifespan. [00:21:10] Ken explains that a primary inhibitor of BDNF is HDAC, and BHB is a powerful inhibitor of HDAC, which leads one to think that one of the mechanisms of exercise to increase BDNF is the elevation of BHB. [00:22:21] Ken mentions that the area under the curve for insulin is one of Peter’s favorite longevity markers, and asks him to talk about the concept of insulin area under the curve.  In addition to blood tests and glucose monitoring, Ken asks Peter what would be the next item of greatest interest in terms of longevity markers. [00:24:28] Dawn mentions that Peter wears an Oura Ring to monitor his sleep, and a glucose monitor to measure his blood sugar in real time. Dawn asks Peter to talk about the benefits of continuous monitoring versus short-term use for the purpose of building future behavior. [00:25:54] Dawn asks if Peter uses any other wearables besides the ones she just mentioned. [00:27:45] Dawn points out that Peter traveled to Easter Island with some friends, including David Sabatini, a guest on episode 70 of STEM-Talk. Dawn asks Peter to talk about the trip which was set up to explore first-hand the place where a group of Canadian researchers first discovered rapamycin. [00:29:13] Ken mentions that Peter is on record saying,