The Sardine Fast is a 450-page, fully-referenced guide to structured sardine-based fasting — the protocol that lets you reach autophagy, ketosis, and metabolic flexibility while sparing the muscle and bone that water fasts erode. 35 peer-reviewed studies. Five protocols. Zero hype.
The CDC estimates that 98 million American adults meet the criteria for prediabetes, and roughly eight in ten have no idea. The International Diabetes Federation counts 537 million adults living with diabetes worldwide, with the curve still bending upward toward 783 million by 2045.
This is not a willpower problem, and for most people it is not genetic destiny. It is the downstream symptom of chronic hyperinsulinemia — and fasting is one of the few physiological levers that pulls that signal back down without a pharmaceutical. The Sardine Fast is the operating manual for pulling it well.
Six parts, thirty-one chapters, and a single promise: every claim is sourced.
Insulin suppression, ketone signaling, autophagy, circadian alignment, and — in longer fasts — stem-cell regeneration. A fast is not one thing; the book takes each in turn.
22–25g of protein, ~1.5g of long-chain omega-3, calcium from the bones, and one of the lowest mercury loads of any fish — eaten without carbohydrate, so insulin barely moves.
The Boz Ratio and the Glucose-Ketone Index — what they measure, how to read them, and the targets that signal you've crossed into metabolic flexibility.
From a daily 17-hour hybrid to a medically-supervised 21-day deep fast — each with the science behind it, the hour-by-hour experience, and how to break it safely.
The anti-catabolic case for protein and omega-3 during a fast — and the refeed protocol that turns a finished fast into actual regeneration.
An honest contraindications chapter — pregnancy, eating-disorder history, certain medications, and the hard-stop symptoms that mean end the fast now.
From Ohsumi's Nobel-winning autophagy work to the clinical trials behind type-2-diabetes remission — this is a sample of the science the book is built on.
The foundational autophagy paper. Earned Ohsumi the 2016 Nobel Prize in Physiology or Medicine.
The canonical NEJM review of intermittent fasting — physiology, clinical evidence, practical protocols.
Coined the 'metabolic switch' — the 12–36h window where the body shifts from glucose to fat-derived ketones.
One-year results of nutritional ketosis for type-2-diabetes remission — best-in-class clinical evidence.
Two-year follow-up: sustained remission, not a short-term fluke.
Mechanistic evidence that fasts beyond 48–72h trigger stem-cell-based regeneration.
BHB is not just fuel — it's an HDAC inhibitor that regulates inflammation and gene expression.
Why the EPA/DHA in oily fish like sardines dampen chronic inflammation.
The toxicology case for small fish: sardines sit near the bottom for methylmercury.
Fasting-mimicking diets recover much of a water fast's benefit with food on board — the sardine-fast rationale.
The definitive reference on why visceral fat is the metabolically dangerous kind.
Decoupled fasting benefits from weight loss — the answer to 'it's just calorie restriction.'
The metabolic emergency around us is not a willpower problem and it is not, for most people, a genetic destiny. It is a downstream symptom of a postwar dietary and lifestyle environment that has driven chronic hyperinsulinemia across whole populations — and fasting is one of a small number of physiological levers that can pull that signal back down without a pharmaceutical.
The cellular process Ohsumi pinned down — autophagy, literally 'self-eating' — is the one biological lever that is reliably engaged by going without food and very poorly engaged by almost any other intervention. The reader of this book can engage it with a clock, a glass of water, and patience.
I have watched a senior surgeon's continuous-glucose trace flatten out so far that he asked, in genuine puzzlement, whether the device was broken. It was not broken. His pancreas had finally been given a chance to rest.
You can trigger autophagy with about a hundred and fifty calories of pure protein and fat sitting in your stomach — provided those calories are not accompanied by the carbohydrates that would re-raise your insulin and shut autophagy back down. You can, in other words, fast smarter.
Each one comes with the science behind it, the hour-by-hour experience, the metrics to watch, and how to break it safely. Start lighter than you think you should.
The everyday lifestyle baseline. Cross the metabolic switch daily inside a 7-hour eating window — sustainable, training-friendly, cycle-aware.
The on-ramp. Two to three cans of sardines in a 4-hour window, then water — cross the 16-hour switch with food on board.
Three days of sardines and water. Drive the Boz Ratio under 80 and ketones to 1.5–3.0 mmol/L — autophagy well underway.
Patterned on the Longo lab's fasting-mimicking work. Open the stem-cell regeneration window while protein and omega-3 spare lean mass.
The deep protocol, modeled on a publicly-documented N=1 with full bloodwork and DEXA. Medical supervision required.
The book doesn't invent the science — it makes the published work usable, with careful attribution to the people who did it.
450 pages. 35 studies. Available in Kindle, paperback, and hardcover.
Mechanistically, yes. Eating a small amount of pure protein and fat keeps insulin low enough for autophagy to ramp up, and the absence of carbohydrate keeps you in fat-burning. You get most of the benefits of a water fast — while sparing the muscle and bone that long water fasts erode. The book is explicit about this distinction.
No. Every claim that touches biology or clinical outcomes is anchored to a peer-reviewed reference — 35 of them, listed at the end of each chapter and consolidated in an annotated bibliography. Where the evidence is mixed, the book says so. There is no 'trust me.'
Never. The book uses 'remission' — not 'cure' — for type 2 diabetes, and only as supported by the Hallberg (2018) and Athinarayanan (2019) clinical cohorts. It is educational, not medical advice, and it tells you plainly when to talk to your doctor.
No. The book stands on its own. The free SardinesFasting iOS app is a companion — it runs the timer, tracks your phase and metrics, and produces a doctor-ready report — but every protocol in the book works with a clock and a glass of water.
Anyone who is pregnant or breastfeeding, under 18, in recovery from an eating disorder, on insulin or sulfonylureas, very lean, or living with serious cardiac, kidney, gallbladder, or liver disease. For those readers the book is something to bring to a physician — not to act on alone.
The complete, fully-referenced guide to the protocol — and the free app that runs it.