The Peter Attia Drive

View the Show Notes Page for This Episode Become a Member to Receive Exclusive Content Sign Up to Receive Peter's Weekly Newsletter Tom Dayspring is a world-renowned lipidologist and one of the most thoughtful teachers in the field of lipid metabolism. In this episode, Tom returns to The Drive for a deep dive into the relationship between lipids and brain health, beginning with the fundamentals of cholesterol transport before exploring why the brain's cholesterol system operates almost entirely independently from the rest of the body. Tom examines the roles of apoB, apoA-I, and especially apoE in cholesterol homeostasis, discusses how APOE genotype influences Alzheimer's disease risk, and unpacks the complex links between cholesterol metabolism, amyloid, and tau pathology. He also reviews what is currently known—and still uncertain—about the effects of statins, ezetimibe, omega-3 fatty acids, and emerging CETP inhibitors on brain health and neurodegenerative disease risk. Although highly technical, this conversation provides an essential framework for understanding the nuanced relationship between lipid-lowering therapies, cardiovascular disease prevention, and neurodegenerative diseases in an area often clouded by misinformation. We discuss: The fundamentals of cholesterol transport in the body, and how peripheral cholesterol metabolism differs from cholesterol handling in the brain [2:45]; How cholesterol is transported through plasma and stored within cells, and why lowering LDL cholesterol does not deplete the body or brain of cholesterol [11:45]; How apoB particles drive atherosclerosis, why lowering lipids matters, and the factors that influence individual cardiovascular risk [20:00]; How the brain produces and transports its own cholesterol using apoE lipoproteins independently of circulating cholesterol and apoB-containing lipoproteins [29:00]; How apoB structure influences LDL receptor binding and LDL clearance [39:00]; How neurons acquire cholesterol from apoE-containing lipoproteins and why desmosterol serves as a unique marker of cholesterol synthesis in the brain [41:45]; The difference between the APOE gene and the apoE protein, the major APOE genotypes found in humans, and how APOE4 influences Alzheimer's disease risk [48:45]; HDL function beyond cholesterol: immune function, protein cargo, and communication with the brain [53:30]; How APOE4-associated defects in brain cholesterol transport may promote Alzheimer's disease: amyloid production, neuronal cholesterol homeostasis, and cholesterol clearance [58:00]; Statins and brain health: reviewing the evidence of the potential impact of statins on cognition and Alzheimer's disease risk [1:09:00]; Desmosterol and 24S-hydroxycholesterol as biomarkers of brain cholesterol metabolism and statin effects [1:17:15]; Possible cognitive benefits of ezetimibe beyond lowering apoB [1:19:30]; EPA, DHA, and the evidence for omega-3 fatty acids in brain health [1:23:15]; Obicetrapib: an emerging CETP inhibitor with potential implications for both cardiovascular and brain health [1:31:00]; and More. Connect With Peter on Twitter, Instagram, Facebook and YouTube

View the Show Notes Page for This Episode Become a Member to Receive Exclusive Content Sign Up to Receive Peter's Weekly Newsletter In this "Ask Me Anything" (AMA) episode, Peter explores how to think critically about medications and supplements by focusing not on whether an intervention is inherently "good" or "bad," but on whether it makes sense for a specific person with a specific problem. He explains why clearly defining the problem matters more than choosing the intervention itself, how the intended purpose of a medication or supplement should influence the standard of evidence required, and why mechanistic reasoning alone is rarely enough to justify taking something. Peter also examines how baseline risk shapes the true benefit of an intervention, why relative risk statistics can be misleading without proper context, and how to weigh not only side effects, but also cost, inconvenience, and opportunity cost when deciding whether something is worth taking. Additionally, he discusses practical ways to evaluate whether a supplement is actually having a meaningful effect, how to think about discontinuing therapies, why supplements deserve far more skepticism than they often receive, and the small group of over-the-counter supplements he believes may offer a reasonable risk-reward trade-off. If you're not a subscriber and are listening on a podcast player, you'll only be able to hear a preview of the AMA. If you're a subscriber, you can now listen to this full episode on your private RSS feed or our website at the AMA #85 show notes page. If you are not a subscriber, you can learn more about the subscriber benefits here. We discuss: How to properly define health problems before considering medications or supplements [1:45]; How the intended purpose of an intervention should determine evidence standards and risk tolerance [5:00]; Understanding the hierarchy of evidence for medications and supplements and avoiding the mistake of treating weak evidence as clinical proof [9:00]; Why mechanistic explanations can be misleading when evaluating longevity interventions [13:15]; How baseline risk—and the distinction between relative and absolute risk reduction—changes the real-world benefit of medications and supplements [18:15]; Thinking beyond side effects: the many forms of downside associated with medications and supplements [22:45]; Why medications and supplements require different standards of trust and evidence [26:00]; How to structure meaningful self-experiments with medications and supplements to determine if it's they're working [30:30]; How to monitor the effects of medications and supplements without fooling yourself [32:30]; How to periodically reevaluate and potentially discontinue medications and supplements [35:15]; The biggest risks and failure modes of over-the-counter supplements: efficacy, poor quality control, contamination, interactions, toxicity, and marketing-driven overuse [38:30]; Why the US supplement regulatory system creates unreliable products [41:45]; A practical framework for evaluating medications and supplements [46:30]; Over-the-counter supplements with the best balance of evidence and low downside risk [48:00]; and More. Connect With Peter on Twitter, Instagram, Facebook and YouTube

View the Show Notes Page for This Episode Become a Member to Receive Exclusive Content Sign Up to Receive Peter's Weekly Newsletter In this episode, Peter takes a deep dive into colorectal cancer (CRC) screening, explaining why it is one of the most preventable cancers and why getting screening right can have life-saving implications. He walks through how colorectal cancer develops and why it is uniquely well-suited to early detection and prevention, with a particular emphasis on the dual role of colonoscopy as both a diagnostic and therapeutic tool. Peter also examines the concerning rise in early-onset CRC among younger adults, highlighting why awareness and timely screening matter more than ever. The episode provides a practical guide to preparing for and evaluating the quality of a colonoscopy, including how to think about appropriate screening intervals and the real risks and tradeoffs involved. Finally, Peter explores the expanding landscape of non-invasive screening options, offering clear insight into what these alternatives can and cannot do so listeners can make informed decisions about their care at any age. We discuss: CRC statistics and goals for this episode [1:00]; Colorectal cancer development: polyp progression, risk types, and the window for prevention [4:00]; Why colorectal cancer is uniquely screenable: direct visualization and the dual role of colonoscopy [6:30]; Colonoscopy effectiveness: prevention through polyp removal and interpreting the NordICC trial data [8:15]; Rising colorectal cancer in younger adults: trends, possible causes, and the case for earlier screening [12:15]; Colonoscopy preparation: why bowel prep matters and how newer options improve the experience [16:45]; Colonoscopy quality, polyp miss rates, and personalized screening intervals [20:00]; Colonoscopy risks versus colorectal cancer risk: understanding the true risk-benefit tradeoff [29:30]; Non-invasive screening options for CRC: benefits, limitations, and their role alongside colonoscopy [37:00]; Colorectal cancer prevention principles: why screening matters and the role of colonoscopy [39:30]; and More. Connect With Peter on Twitter, Instagram, Facebook and YouTube

View the Show Notes Page for This Episode Become a Member to Receive Exclusive Content Sign Up to Receive Peter's Weekly Newsletter In this episode, Peter explores one of the most foundational topics underlying nearly everything discussed on the podcast: how to think scientifically. Framed as an introspective deep dive, he examines why scientific thinking is inherently difficult for humans, the cognitive biases and tendencies that make it challenging to separate belief from evidence, and why these challenges are even more consequential in today's environment saturated with misinformation. He also offers a framework for improving our ability to evaluate claims, question assumptions, and identify a personal panel of experts, providing listeners with practical tools to become more disciplined and effective thinkers. We discuss: Topics to be covered and goals for this episode [2:00]; Scientific thinking: hypotheses, uncertainty, and the process of ruling out explanations [3:45]; How scientific knowledge differs from mathematical proof: useful approximations, evolving evidence, and acting under uncertainty [8:00]; Why scientific thinking is difficult: evolution, social instincts, and the need for deliberate practice [13:30]; Systems and tools designed to correct human bias [18:15]; How to think scientifically pt. 1: Notice when you're feeling certain [20:30]; How to think scientifically pt. 2: Judge the process, not just the conclusion [23:00]; How to think scientifically pt. 3: Notice when identity is shaping your beliefs [28:15]; How to think scientifically pt. 4: Don't confuse criticism with understanding [33:45]; How to think scientifically pt. 5: Outsource your thinking carefully [36:15]; Evaluating who to trust: incentives, consensus, and red flags in scientific credibility [45:15]; Science as a self-correcting system: why updating with evidence is a strength, not a weakness [49:00]; The key principles of scientific thinking, and a practical framework for evaluating claims and improving judgment [50:45]; and More. Connect With Peter on Twitter, Instagram, Facebook and YouTube

View the Show Notes Page for This Episode Become a Member to Receive Exclusive Content Sign Up to Receive Peter's Weekly Newsletter In this "Ask Me Anything" (AMA) episode, Peter explores the topic of gray-market peptides, one of the most requested and most confusing topics he's covered on The Drive. Peptides sit at the intersection of biological plausibility, clinical promise, and aggressive commercialization, and are often marketed as cutting-edge therapies for everything from muscle repair and longevity to cosmetic enhancement. Rather than promoting or dismissing peptides wholesale, Peter lays out a clear, repeatable framework for evaluating any peptide or drug—covering mechanism, intended effects, safety, dosing, and alternatives. He distinguishes FDA-approved peptide therapeutics from the loosely regulated "peptides" common in biohacking culture; examines the strengths and limitations of animal and human evidence; unpacks manufacturing, gray-market sales, "research use only" labeling, and third-party testing; addresses oral peptides and absorption challenges; and explains how patents and incentives shape which compounds advance through clinical pipelines. The discussion concludes with a sober look at what would need to change for peptides to become broadly usable therapies, where legitimate peptide therapeutics may expand next, and which areas of medicine stand to benefit most right now. If you're not a subscriber and are listening on a podcast player, you'll only be able to hear a preview of the AMA. If you're a subscriber, you can now listen to this full episode on your private RSS feed or our website at the AMA #83 show notes page. If you are not a subscriber, you can learn more about the subscriber benefits here. We discuss: Setting the framework for evaluating peptides, and explaining the goal of this discussion [3:15]; What peptides are: basic definitions, biological roles, and therapeutic foundations [5:30]; A framework for evaluating peptides: mechanism, evidence, safety, and regulatory context [10:00]; Peptide case study—SS-31: mechanism of action, approved use in Barth syndrome, and other claimed effects [18:15]; Does the mechanistic rationale for SS-31 translate into measurable benefits? [22:15]; SS-31 continued: safety considerations, gray market risks, the balance of risk versus reward, and why it belongs in bucket #3 [26:00]; Peptide case study—melanotan-II: claimed effects, mechanism of action, safety, and side effects [30:45]; Melanotan-II continued: weighing the potential risks versus benefits and why it belongs in bucket #2 [36:30]; Peptide case study—CJC-1295: growth hormone–stimulating mechanism, claimed effects, and limited human data [40:15]; CJC-1295 continued: dosing uncertainty, risk-reward analysis, lack of long-term safety data, limited approved options, and why it belongs in bucket #2 [49:30]; Peptide case study—BPC 157: uncertain origins, broad claims, and weak mechanistic evidence [57:45]; BPC 157 continued: review of human evidence, lack of replication of animal data, safety considerations, risk-reward analysis, and why it belongs in bucket #1 [1:03:15]; Other popular "gray market" peptides and why they mostly fail when under scrutiny [1:11:15]; How the evidence on peptides compares to rapamycin, and why the lack of data is the biggest concern [1:20:00]; Understanding peptide regulation: FDA approval, supplement oversight, and the risks of gray-market compounds [1:23:00]; Inside the gray market: how peptides are sold, regulated, and why testing cannot guarantee safety [1:26:45]; Limitations of oral peptides, and examples of peptides in bucket #4 [1:31:45]; The future of peptides: real therapeutic potential versus hype in the wellness market [1:35:00]; and More. Connect With Peter on Twitter, Instagram, Facebook and YouTube

View the Show Notes Page for This Episode Become a Member to Receive Exclusive Content Sign Up to Receive Peter's Weekly Newsletter In this "Ask Me Anything" (AMA) episode, Peter answers listener questions across a wide range of topics, focusing on practical decision-making and real-world application. He explores how health priorities and strategies should evolve across different decades of life, which chronic diseases are most challenging to manage and how to think about risk hierarchies, and which emerging interventions—beyond exercise—show the most promise for dementia prevention. Peter also breaks down the utility of wearables and explains how to use and interpret DEXA scans effectively. He discusses the challenges of behavior change and how to make healthy habits stick, along with training strategies for balance, stability, and injury resilience, drawing lessons from his own setbacks. Additional topics include high-protein diets and mTOR, how to weigh mechanisms versus outcomes, how to evaluate diet sodas and non-nutritive sweeteners in context, and a range of listener questions covering health fads, emotional health, and sleep routines. If you're not a subscriber and are listening on a podcast player, you'll only be able to hear a preview of the AMA. If you're a subscriber, you can now listen to this full episode on your private RSS feed or our website at the AMA #82 show notes page. If you are not a subscriber, you can learn more about the subscriber benefits here. We discuss: Overview of episode topics, emphasizing the goal of providing actionable, real-world health guidance [1:30]; How health priorities and training strategies should evolve from early adulthood through older age [2:45]; Comparing the four major chronic diseases: which are most preventable, most uncertain, and most concerning [8:00]; Emerging strategies for dementia prevention: biomarkers, early detection, and new pharmacologic approaches [15:00]; How to use wearable data effectively: when it's helpful, when it's not, and how to avoid over-reliance [19:00]; DEXA scans: timing, interpretation, and limitations in body composition and bone density tracking [23:00]; Best practices for building sustainable health habits [30:15]; How to train your balance and stability [33:30]; How to recover from injuries and use setbacks to build strength and resilience [36:15]; High protein intake and the impact on mTOR: evaluating mechanisms versus real-world evidence on longevity [38:30]; Diet soda and artificial sweeteners: evaluating risks, benefits, and the importance of context [47:00]; How to balance enjoying life today with making choices that support long-term health and longevity [51:45]; and More. Connect With Peter on Twitter, Instagram, Facebook and YouTube

View the Show Notes Page for This Episode Become a Member to Receive Exclusive Content Sign Up to Receive Peter's Weekly Newsletter Layne Norton is a nutrition scientist and accomplished power athlete,who returns to The Drive for a conversation that departs from the show's usual format. In this episode, Layne presents the evidence-based case that seed oils are not uniquely harmful under isocaloric conditions, while Peter steelmans the strongest versions of the opposing argument that seed oils are inherently harmful. They examine how scientific bias and evidence are evaluated, revisit the historical randomized controlled trials that shaped the seed oil controversy, and explore the mechanistic biology underlying LDL oxidation and atherosclerosis. Along the way, Layne unpacks the chemistry and processing of modern seed oils, assesses evolutionary and ancestral nutrition arguments, clarifies the relationship between seed oils, ultra-processed foods, and contemporary dietary patterns, and situates these questions within the larger context of lifestyle factors that drive cardiometabolic health. Layne concludes by offering practical considerations around dietary fats, cooking oils, and real-world food choices. We discuss: The idea behind this episode, biases, and evidence-based thinking [5:15]; The four core arguments behind claims that seed oils are harmful [12:30]; The Minnesota Coronary Experiment (MCE) [14:30]; The differences among saturated, monounsaturated, polyunsaturated, and trans fats, and why those differences matter for cardiovascular disease [18:30]; Missing trans fat data as a confounder in the Minnesota Coronary Experiment, other limitations of that study, and the challenge detecting meaningful differences in hard outcomes through nutrition research [24:00]; The Sydney Diet Heart Study (SDHS): an attempt to address the "duration problem" by enrolling a much higher-risk population [28:30]; Debating whether evidence from randomized trials supports the idea that seed oils are uniquely harmful once major confounders are removed [34:00]; The Rose Corn Oil trial: an often-cited study used to argue against polyunsaturated fats [36:30]; Three studies where replacing saturated fat with polyunsaturated fat produced different results than earlier trials [41:30]; Layne's explanation for why the evidence is pointing towards cardiovascular risk reduction when substituting polyunsaturated fat for saturated fat [47:30]; What Mendelian randomization says about the causal role of LDL cholesterol in ASCVD [56:45]; The compounding effects of life-long exposure to high LDL cholesterol [1:06:45]; Does the linoleic acid (omega-6) content of seed oils cause inflammation? [1:13:45]; Does the linoleic acid (omega-6) content of seed oils increase oxidized LDL? [1:19:30]; Layne's analogy to explain why lower LDL particle number outweighs higher per-particle oxidation risk when comparing polyunsaturated fats to saturated fats [1:26:15]; The role of oxidized LDL in CVD: exploring differences in a diet high in polyunsaturated fat (seed oils) versus high in saturated fat [1:28:00]; Examining whether industrial processing and solvent extraction of seed oils—especially residual hexane—could plausibly cause long-term harm [1:34:00]; The evolutionary and "ancestral diet" argument against seed oils [1:40:45]; Weighing concerns about industrial processing of seed oils against the totality of metabolic and cardiovascular evidence [1:47:30]; Practical considerations around dietary fats, cooking oils, and real-world food choices [1:50:00]; Comparing the health impact of seed oils with that of caloric intake and activity levels, and how to prioritize interventions [2:00:15]; More. Connect With Peter on Twitter, Instagram, Facebook and YouTube

View the Show Notes Page for This Episode Become a Member to Receive Exclusive Content Sign Up to Receive Peter's Weekly Newsletter Abbie Smith-Ryan is a leading researcher in exercise physiology whose work focuses on how training and nutrition influence body composition, metabolism, cardiovascular health, and women's health across the lifespan, with particular attention on perimenopause and post-menopause. In this episode, Abbie explains how early exercise and play help build the foundation for bone health, muscle development, and cardiorespiratory fitness in girls, as well as how puberty and menstruation shape athletic performance, motivation, and recovery. She also explores how women can tailor training and nutrition across the menstrual cycle through smart fueling, hydration, and inflammation management; examines the evidence behind supplements such as creatine, omega-3s, and magnesium; and unpacks the metabolic and body composition changes that accompany the transition into perimenopause and menopause. Finally, she covers practical exercise programming for busy women, training and nutrition considerations during pregnancy and postpartum, and the evolving role of hormone therapy alongside lifestyle-based, evidence-driven approaches that help women better advocate for their health. We discuss: Abbie's background in distance running and her interest in studying women's health around exercise [3:00]; The role of early-life exercise in building lifelong bone, muscle, and cardiovascular health in girls [4:00]; Training principles for premenstrual girls, the risks of early specialization and delayed puberty from intense training, and how youth sport participation can shape bone and spinal health [7:15]; Nutrition as fuel in young female athletes: supporting training, growth, and performance [11:00]; Training and recovery across the menstrual cycle: recovery, nutrition, supplements, and practical strategies for performance support [16:00]; The benefits of creatine supplementation and importance of protein intake across the menstrual cycle [27:15]; How women should approach training intensity and volume across the menstrual cycle [33:00]; How to identify and monitor the perimenopausal transition and why this phase represents a critical window for exercise and nutrition interventions [37:15]; Case study: time-efficient exercise program for a busy, perimenopausal woman [42:00]; Why improving body composition is a better goal than weight loss, and how to set realistic fat-loss targets in midlife women [53:30]; How to preserve muscle and bone while using GLP-1 medications: resistance training, protein intake, and more [58:15]; Designing a three-hour-per-week training plan for sustainable body recomposition [1:03:30]; Abbie's insights from her 20+ years of self-tracking: nutrient timing, injury prevention, excessive training, bone health, and more [1:07:15]; How pregnancy and the postpartum period affect body composition, and how consistent exercise and intentional nutrition can prevent a permanent shift in body fat or muscle mass [1:13:30]; Changes in muscle quality and metabolic flexibility during perimenopause and menopause, and how exercise may counteract hormonally driven sarcopenia [1:21:45]; The biggest open questions about women's health: combining menopause hormone therapy with exercise, GLP-1 drugs, minimizing injury risk, and more [1:32:00]; How the training response differs between men and women, and the importance of type IIa muscle fibers [1:39:15]; Training advice for the hypothetical 70-year-old woman who has never exercised deliberately [1:47:00]; Misinformation about exercise and nutrition for women, injury risk, supplement hype, and the need for more nuanced messaging around hormones, recovery, and midlife training [1:53:30]; Benefits of hormone therapy in midlife women and its interaction with exercise and lifestyle interventions [2:00:15]; Peter's overall take on how women should approach exercise volume and intensity at various life phases and time constraints [2:03:00]; and More. Connect With Peter on Twitter, Instagram, Facebook and YouTube

View the Show Notes Page for This Episode Become a Member to Receive Exclusive Content Sign Up to Receive Peter's Weekly Newsletter In this special episode of The Drive, Peter presents a curated "best of" conversation with bestselling author and previous guest Arthur Brooks, organized around four core themes: happiness itself, the forces that undermine it, the tools and practices that help cultivate it, and the courage required to live and love well. The episode brings together the most meaningful moments from two past interviews into a single, focused discussion that distills Brooks' most insightful ideas and offers practical takeaways for building a life that's both successful and deeply happy. We discuss: Happiness vs. happy feelings, and how happiness and unhappiness can coexist [2:15]; The six fundamental emotions [5:30]; The three main "macronutrients" of happiness [15:00]; Enjoyment: one of the three macronutrients of happiness [22:45]; Satisfaction: one of the three macronutrients of happiness [30:45]; Sense of purpose: one of the three macronutrients of happiness [38:45]; Fame: one of the traps that hijack our happiness [46:30]; Success addiction, workaholism, and their detriment to happiness [49:15]; The reverse bucket list: one of Arthur's tools and practices he recommends for moving past the traps that hijack our happiness [59:15]; Metacognition: one of Arthur's tools and practices he recommends for moving past the traps that hijack our happiness [1:01:00]; Taking charge of your happiness: discipline, transcendent experiences, and other deliberate actions for "happier-ness" [1:11:30]; Tracking happiness: the biomarkers and micronutrients behind the macronutrients of happiness [1:22:45]; The value of minimizing the self and looking outward [1:30:45]; How Arthur surprised himself with his ability to improve his happiness [1:34:45]; and More. Connect With Peter on Twitter, Instagram, Facebook and YouTube

View the Show Notes Page for This Episode Become a Member to Receive Exclusive Content Sign Up to Receive Peter's Weekly Newsletter Dom D'Agostino is a neuroscientist and professor at the forefront of metabolic therapies, including ketogenic diets, exogenous ketones, and hyperbaric oxygen. In this episode, Dom breaks down nutritional versus supplemental ketosis, defines meaningful ketone thresholds, and outlines practical ways to achieve ketosis. He explains how a ketogenic diet can support metabolic health and weight loss, and advises on how to maintain adequate protein and avoid common mistakes. Dom surveys the growing landscape of exogenous ketones—from salts and esters to 1,3-butanediol—and effective pairings like caffeine, MCT oil, and alpha-GPC. He highlights the role of ketogenic therapy in cancer (particularly glioblastoma) and its promise for neurodegenerative diseases. The conversation also covers recommended hyperbaric oxygen protocols for brain injuries and cognitive function, situations where fasting or ketones offer cognitive and anti-inflammatory benefits, and touches on the carnivore diet as a ketogenic variant with potential relevance for autoimmune and metabolic conditions. We discuss: Dom and Peter's shared interest in ketosis, and Dom's scientific journey [2:30]; Dom's work for the Navy on oxygen toxicity [7:00]; Nutritional ketosis defined: physiology, biomarkers, and how fasting and diet generate therapeutic ketones [15:00]; The historical roots of ketogenic diets in epilepsy treatment, and evidence showing ketones reduce seizure activity and strengthen brain resilience [19:00]; Dom's personal experience on the ketogenic diet: tracking macros, getting enough protein, and monitoring ketone levels [24:15]; Using a ketogenic diet for weight loss: Dom's guidance on protein, fiber, calorie tracking, lipid monitoring, and more [31:00]; Protein on ketogenic diets: Dom's rationale for higher intake and muscle preservation [38:00]; Incorporating carbohydrates into keto: timing, high-fiber foods, and other considerations [41:30]; The carnivore diet: whether this diet induces ketosis, how it functions metabolically, and why it may help individuals with autoimmune conditions [44:15]; Early exogenous ketones: how 1,3-butanediol works, its liver toxicity risk, and why ketone esters replaced it [48:15]; The progression of exogenous ketones: why BHB monoesters and ketone salts emerged as better alternatives to 1,3-butanediol for ketone supplementation [59:30]; Ketone salts: easing the transition into ketosis, dosing, and how they compare to ketone esters [1:04:00]; The differences between D- and L-β-hydroxybutyrate, and how racemic mixtures may elevate ketones longer and offer unique biological effects [1:09:30]; How ketosis may boost NAD, and why NAD supplements have fallen short so far [1:16:30]; Emerging evidence for using a ketogenic diet to treat anorexia and other psychiatric disorders [1:20:30]; Potential cognitive and performance benefits of ketone supplementation, and why pushing ketones too high can be dangerous [1:23:45]; Applications for ketone esters, and why ketone salts or MCT-blended formulations may be safer and more practical for most people [1:29:15]; The role of a ketogenic diet in treating cancer [1:34:45]; The potential of a ketogenic diet for treating Alzheimer's disease [1:45:45]; Tools for cognitive enhancement: ketones, alpha-GPC, MCT, caffeine, strategic fasting, and more [1:53:45]; Hyperbaric oxygen therapy for concussion, TBI, PTSD, and cognitive function, including protocols and dosing approaches [1:55:30]; Peter's takeaways, recommended products, and additional resources to learn more [2:03:00]; and More. Connect With Peter on Twitter, Instagram, Facebook and YouTube

View the Show Notes Page for This Episode Become a Member to Receive Exclusive Content Sign Up to Receive Peter's Weekly Newsletter Walter Green is a remarkable philanthropist, mentor, author of This Is the Moment!, and founder of the impactful "Say It Now" movement. In this episode, Walter delves into the unique insights gained from his challenging upbringing, discusses embracing mortality, and highlights the mindset of "finishing strong." He shares insights on intentionality, thinking in reverse, saying "no," prioritizing relationships, and the essence of focusing on others. The conversation focuses on the "Say It Now" movement, which stresses the importance of expressing sentiments to loved ones well before the end of life. We discuss: How Peter and Walter met through Ric Elias [3:30]; The unique perspectives and life lessons provided by Walter's challenging childhood [6:00]; Walter's harrowing experience with a sudden mental breakdown and his subsequent recovery with the help of therapy [12:15]; A diverse professional journey ending in great success [19:15]; The birth of a movement: celebrating friendships through public tributes and expressing gratitude to those who have shaped your life's journey [23:30]; Intentionality, thinking in reverse, saying "no", and other guiding principles for Walter [30:45]; Walter's global journey of gratitude on his 70th birthday, visiting friends, and creating memorable experiences [40:15]; The profound impact of acknowledging and expressing gratitude for the people who contribute to our lives [47:15]; The key elements for creating meaningful connections and cultivating deep, authentic friendships [53:15]; The "Say It Now" movement: the inspiration behind the remarkably impactful initiative [59:15]; What "finishing strong" means to Walter [1:08:15]; Finding peace at the end of life through expressing gratitude and finding purpose in serving others [1:16:45]; Resources to learn about "Say It Now" [1:27:00]; and More. Connect With Peter on Twitter, Instagram, Facebook and YouTube

View the Show Notes Page for This Episode Become a Member to Receive Exclusive Content Sign Up to Receive Peter's Weekly Newsletter In this "Ask Me Anything" (AMA) episode, Peter breaks down the science of dietary fiber, moving beyond the blanket advice to "eat more fiber" to uncover what it actually does in the body and where its benefits are truly supported by evidence. He explains how different types of fiber—soluble, insoluble, viscous, and fermentable—affect digestion, satiety, weight management, and glycemic control, and compares their impact to other, more potent metabolic tools. Peter also examines how certain fibers influence lipid metabolism and cardiovascular risk, evaluates the strength of evidence for fiber's role in colorectal cancer prevention, and highlights why some individuals may not tolerate specific fibers well. The discussion concludes with practical guidance on moving past generic fiber targets toward a more strategic and personalized approach that maximizes the true benefits of fiber. If you're not a subscriber and are listening on a podcast player, you'll only be able to hear a preview of the AMA. If you're a subscriber, you can now listen to this full episode on your private RSS feed or our website at the AMA #77 show notes page. If you are not a subscriber, you can learn more about the subscriber benefits here. We discuss: Why it's time to re-examine the evidence behind dietary fiber recommendations [2:00]; Why it's hard to isolate fiber's true effects on health: the limits of nutritional epidemiology [5:45]; Defining dietary fiber: what it is, how it's digested, and why different types have different effects [8:15]; Understanding fiber properties: how solubility, viscosity, and fermentability shape its effects in the body [11:15]; Resistant starches explained: types, food sources, and how cooking and cooling influence their benefits [16:30]; A framework for evaluating each of the major health claims linked to fiber [19:15]; How fiber can support weight loss: mechanisms, realistic expectations, and its complementary role to broader dietary strategies [20:30]; How fiber modestly improves glycemic control by reducing glucose spikes and insulin demand [26:15]; How fiber modestly lowers LDL cholesterol and supports cardiovascular health [34:30]; How fiber compares to other available tools and strategies for managing lipids, blood sugar, and weight [42:00]; Fiber's role in colon cancer prevention: mechanisms, evidence, and limitations [45:30]; Is fiber necessary for colon cancer prevention in otherwise healthy individuals? [53:30]; Why some people have adverse reactions to certain types of fiber, and how to manage them [56:00]; A general strategy for dietary fiber: combine multiple fiber types through whole foods and supplements [58:45]; Why total fiber intake is more important than the ratio of soluble-to-insoluble fiber [1:02:45]; The optimal timing and context for consuming fiber to maximize blood sugar control and metabolic benefits [1:05:00]; How food processing affects the functional properties of fiber, the differences between supplement forms and natural sources, and why whole foods generally remain the best option [1:06:45]; Fiber's potential to interfere with medication absorption [1:09:30]; How to safely increase fiber intake: ramp up gradually and stay hydrated [1:12:00]; Final takeaway on fiber: modest benefits, strong rationale, low downside [1:13:00]; Peter's carve-out: lessons and inspiration from the Acquired podcast [1:14:30]; and More. Connect With Peter on Twitter, Instagram, Facebook and YouTube

View the Show Notes Page for This Episode Become a Member to Receive Exclusive Content Sign Up to Receive Peter's Weekly Newsletter In this special episode, Peter provides a comprehensive introduction to longevity, perfect for newcomers or those looking to refresh their knowledge. He lays out the foundational concepts of lifespan, healthspan, and the marginal decade. Additionally, Peter discusses the four main causes of death and their prevention, as well as detailing the five key strategies in his longevity toolkit to improve lifespan and healthspan. Detailed show notes provide links for deeper exploration of these topics, making it an ideal starting point for anyone interested in understanding and improving their longevity. We discuss: Key points about starting exercise as an older adult [2:45]; Overview of episode topics and structure [1:45]; How Peter defines longevity [3:45]; Why healthspan is a crucial component of longevity [11:15]; The evolution of medicine from medicine 1.0 to 2.0, and the emergence of medicine 3.0 [15:30]; Overview of atherosclerotic diseases: the 3 pathways of ASCVD, preventative measures, and the impact of metabolic health [26:00]; Cancer: genetic and environmental factors, treatment options, and the importance of early and aggressive screening [33:15]; Neurodegenerative diseases: causes, prevention, and the role of genetics and metabolic health [39:30]; The spectrum of metabolic diseases [43:15]; Why it's never too late to start thinking about longevity [44:15]; The 5 components of the longevity toolkit [46:30]; Peter's framework for exercise—The Centenarian Decathlon [47:45]; Peter's nutritional framework: energy balance, protein intake, and more [58:45]; Sleep: the vital role of sleep in longevity, and how to improve sleep habits [1:08:30]; Drugs and supplements: Peter's framework for thinking about drugs and supplements as tools for enhancing longevity [1:13:30]; Why emotional health is a key component of longevity [1:17:00]; Advice for newcomers on where to start on their longevity journey [1:19:30]; and More. Connect With Peter on Twitter, Instagram, Facebook and YouTube