Fasting shows up on nearly every health podcast in some form, but most of the advice is recycled from the same three talking points. The episodes below are different. Pulled from our full library of episode summaries, they cover fasting from the angles that actually matter: what it does to insulin and visceral fat, why it works differently in women's bodies, how extreme versions of it can backfire, and why some of the biggest names in longevity science quietly disagree with each other about it.
Expect cardiologists, Harvard geneticists, a magician who nearly died fasting on stage, and a psychiatrist treating schizophrenia with diet instead of drugs. Some of these guests are true believers, some are skeptics, and a couple contradict each other outright. Read them together and you get a far more complete picture than any single fasting guru will give you.
Insulin Doctor: The Fastest Way To Burn Dangerous Visceral Fat! I'm Finding Mould In My Patients!
A cardiologist with roughly 35 years of practice and a quarter-million patients treated makes the plainest case on this list for why fasting, not just calorie counting, is what actually lowers insulin and burns visceral fat. He describes supervising one severely overweight, diabetic patient through a 72-day fast that reversed her diabetes and blood pressure, and another who fasted 183 days and dropped from 400 pounds to 210. He also throws in a genuinely startling claim that nearly 70% of homes carry some level of mold toxicity that worsens heart disease. Listen if you want the medical case for fasting from someone who has spent decades staring at clogged arteries.
Read the full episode notesThe Miracle Doctor: Get Your Sex Life Back, Melt Belly Fat & Heal Your Injury! Dr. Mindy Pelz | E256
The author of Fast Like a Girl breaks fasting down by the clock, explaining what happens at 13 hours (a claimed 1,300% spike in testosterone in men), at 17 hours (the onset of autophagy, the cell-recycling process that won Dr. Ohsumi a 2015 Nobel Prize), and at 36 hours (the point she says unsticks stubborn weight-loss resistance). She also covers Dr. Valter Longo's research showing three days of fasting can reboot white blood cells during chemotherapy. This is the most practical, hour-by-hour fasting explainer on the list, and it is aimed squarely at women's hormonal cycles. Listen if you want an actual protocol, not just a philosophy.
Read the full episode notesExercise & Nutrition Scientist: The Truth About Exercise On Your Period! Take These 4 Supplements!
This is the essential counterweight to the rest of the list. Exercise physiologist Stacy Sims argues that most fasting research is built on data from 18 to 22 year old men, and that popular 'warrior style' 20-hour fasting protocols backfire on women, raising blood glucose, increasing fat storage, and downregulating the thyroid within four days. She walks through how fasting should shift across the menstrual cycle and into perimenopause instead. Anyone who has tried a men's-media fasting plan and found it made things worse should start here.
Read the full episode notesAll Things Ketones, How to Boost Cognition, Sardine Fasting, Diet Rules, & More — Dr. Dom D’Agostino
A metabolic researcher who studies ketones for Alzheimer's, cancer, and psychiatric disease explains why he skips water-only fasts in favor of what he calls 'sardine fasting,' eating one can of sardines a day for a week, once a month. He recounts a cancer patient who used the protocol and went into remission from metastatic prostate cancer despite a three-month prognosis, then lived years longer before dying of something unrelated. The conversation also digs into why a ketogenic diet and fasting boost the immune system through different mechanisms. Listen if straight water fasting sounds miserable and you want a gentler entry point backed by lab science.
Read the full episode notesMaster Magician David Blaine — Fear< with Tim Ferriss
The magician's account of his 44-day water fast inside a box in London is the cautionary tale every fasting enthusiast should hear. He describes going into mild organ failure, losing 60 pounds, and then nearly going into shock during refeeding when his phosphate levels spiked out of control. He also explains how an earlier attempt to slow his metabolism by starving himself before a breath-hold stunt backfired and nearly caused him to black out underwater while handcuffed. This is fasting pushed to its absolute physical limit, told by someone who paid for it in organ damage. Listen for the visceral reminder that extended fasting is not risk-free.
Read the full episode notesEssentials: The Biology of Slowing & Reversing Aging | Dr. David Sinclair
Harvard geneticist David Sinclair lays out why he treats aging itself as a disease and where fasting fits into his personal anti-aging toolkit. He reveals a 'pulsing' protocol of rotating fasting, eating, supplements, and exercise that he says he had not shared publicly before this conversation, and he is candid that the science behind it is unfinished, saying flatly that even he doesn't know what's optimal for himself. The episode also covers his blood-sugar and mTOR reasoning for why fasting slows the epigenetic 'scratches' he believes drive aging. Listen if you want fasting explained through the lens of cutting-edge longevity biology rather than a diet book.
Read the full episode notesDr David Sinclair: Can Aging Be Reversed? After 8 Weeks, Cells Appeared 75% Younger In Tests!
This longer, wider-ranging conversation covers Sinclair's full information theory of aging, including a human age-reversal trial for blindness set to begin about a month after this recording, and an independent lab result showing his three reset genes doubled lifespan in very old mice. Fasting is folded in as one of several practical longevity levers alongside exercise, a plant-heavy diet, and sauna, and he shares the striking finding that lifestyle, not genetics, accounts for roughly 80 to 90% of how fast a person ages. Listen for the bigger picture of why researchers like Sinclair fast in the first place.
Read the full episode notesDr. Peter Attia — Longevity Drugs, Alzheimer's Disease, and More
Peter Attia offers the sharpest skeptic's take on this list, warning that excessive time-restricted feeding without strength training can quietly cause muscle loss, citing a patient whose body fat jumped from 18% to 30% with no change in weight, plus his own jump from 10% to 16%. He balances that caution against a wide tour of longevity science, from liquid biopsy cancer screening to rapamycin's roughly 11 to 19% lifespan extension in the rigorous NIH Interventions Testing Program. Listen if you want fasting weighed honestly against its real trade-offs rather than sold as a cure-all.
Read the full episode notesThe Cancer Doctor: "This Common Food Is Making Cancer Worse!"
A Boston College biologist argues cancer is fundamentally a mitochondrial metabolic disease rather than a genetic one, and that restricting the glucose and glutamine tumors depend on, aided by fasting and ketosis, can slow or starve them. He tells the story of glioblastoma patient Pablo Kelly, who rejected chemo and radiation and survived a decade on metabolic therapy before eventually dying from surgery, not cancer. He's also blunt that the standard cancer drug Avastin is, in his words, 'an immoral drug that should never be used on people.' Listen for the most radical medical argument for fasting on this list.
Read the full episode notesA day in my life | Lex Fridman
In this day-in-the-life video, Lex Fridman shows what fasted training actually looks like folded into a real schedule: he runs at least six miles completely fasted, going 14 to 16 hours without food and taking only a salt pill for electrolytes, before eating a single keto meal of about two pounds of grass-fed beef and vegetables. The routine also includes two four-hour deep-work blocks and a Goggins-style bodyweight workout. Listen if you want to see fasting used as one gear in a disciplined daily system rather than discussed as a standalone health topic.
Read the full episode notesDiet & Nutrition for Mental Health | Dr. Chris Palmer
A Harvard psychiatrist explains how metabolic interventions related to fasting, especially the ketogenic diet, have helped patients with severe, treatment-resistant mental illness. He describes a schizoaffective patient whose auditory hallucinations began resolving six to eight weeks into a ketogenic diet with no medication change, who went on to lose 160 pounds and move out to live independently. In a French pilot study he cites, all 28 treatment-resistant patients improved and 46% reached remission. Listen if you think of fasting purely as a weight-loss or longevity tool and want to see its most surprising application yet.
Read the full episode notesImprove Energy & Longevity by Optimizing Mitochondria | Dr. Martin Picard
A Columbia mitochondrial psychobiologist reframes fasting as one input into a much bigger idea: that mitochondria act as energy-transforming antennas linking your psychology and stress to how you age. He shares the striking finding that hair graying is at least temporarily reversible, with one participant's white hair segment mapping almost exactly to her two most stressful months before reversing. He's also skeptical of the supplement and peptide craze, revealing he has never taken a single supplement himself. Listen for the deepest dive into why fasting works at the cellular level, minus the hype.
Read the full episode notesThe Heart Surgeon: Cardio Is A Waste Of Time For Weight Loss! Philip Ovadia | E240
A heart surgeon who performed over 3,000 operations recounts being a morbidly obese, pre-diabetic doctor before reversing his own metabolic disease, which reframed fasting and diet as more important to him than cardio or calorie counting. He argues broken metabolic health, not genetics, is the root cause of heart disease, diabetes, cancer, and Alzheimer's alike. His most candid moment comes when he admits he isn't sure he can solve the health crisis he's dedicated his career to. Listen for the doctor's-eye view of why metabolic health, with fasting as one tool, matters more than most people realize.
Read the full episode notesControlling Sugar Cravings & Metabolism with Science-Based Tools | Huberman Lab Podcast #64
Huberman doesn't focus on fasting directly here, but he explains the science that makes fasting hard in the first place: three parallel brain circuits, including gut cells signaling through the vagus nerve, that drive sugar cravings regardless of willpower. He also flags a study showing that fasting can distort visual perception by blurring the tuning of visual-cortex neurons. Useful context if you've ever wondered why the last few hours of a fast feel like a fight against your own brain. Listen if you want the neuroscience behind why cravings hit and how to blunt them.
Read the full episode notesBoost Your Energy & Immune System with Cortisol & Adrenaline | Huberman Lab Essentials
This Huberman Essentials episode reframes cortisol and adrenaline as tools rather than enemies, with circadian eating and fasting folded in as ways to regulate them. He cites a 2014 study where deliberate breathing attenuated fever symptoms from an injected pathogen, supporting the idea that brief, controlled stress, the same category fasting falls into, can strengthen rather than weaken the immune system. Listen for how fasting fits into a broader toolkit of managed stress rather than standing alone.
Read the full episode notesFasting means something different in each of these conversations, from a cardiologist's 72-day medical protocol to a magician's near-fatal stunt. Browse our full library of episode summaries to find the specific angle, cardiovascular, hormonal, psychiatric, or otherwise, that fits what you're actually trying to solve.