Thirty-three years of testing things on myself.

Early body hacking

Cold exposure, breath work, varying sleep schedules, every diet that went through a credible review cycle — I tried most of them. Some helped. Some did nothing. A few were worse than the baseline. I started keeping logs because memory is a bad biographer; it edits in your favor.

I started at eighteen with vegetarianism, because the early-1990s arguments were convincing and the sources I trusted at the time pointed that way. I held it for years, watched my energy and clarity quietly drop, and eventually had to admit my own data didn’t support what I wanted to believe. The lesson wasn’t “vegetarian is wrong.” The lesson was that whatever I chose, I needed to write down what actually happened.

Diet experimentation

Standard western, then vegetarian, then strict paleo, then ketogenic, then carnivore, then cyclical. Each one held up some claims and quietly violated others. I came out of it with a low-carb / keto baseline because that’s the diet under which my own biomarkers, sleep, and lifting performance hold steady — not because of dogma. I consider the question of optimal macronutrient ratios still open.

Across roughly six hundred cumulative days in measurable ketosis over the past few years, the pattern has been stable: fasting glucose, fasting insulin, triglycerides, and morning ketones move in the directions I want them to and stay there. Sleep architecture changed too — deeper, fewer wake-ups, dreams I can remember in the morning. None of those endpoints prove the diet for everyone, but they answer the question for me.

How sardine fasting entered the picture

The first time I read about sardine fasting, it was a footnote in a discussion about protein-sparing modified fasts. The logic was elegant: keep insulin low, keep nitrogen balance positive, keep omega-3s coming in, do it for a finite window. I expected it to be unpleasant. It wasn’t.

My first three-day cycle was simple: a single brand of canned sardines, two cans a day, water and a generous pinch of salt. By day three I was the most cognitively clear I’d been in months. The refeed taught me more than the fast itself — I had energy back to baseline before the scale settled, which made me start logging biomarkers across the whole window, not just at the endpoints.

From first cycle to twenty-plus

I’ve now run more than twenty sardine fasting cycles. The protocol has stabilized into the three variants you see on this site. The variant I choose for any given month depends on the season, my recent training load, and whatever else is on the calendar.

One full cycle log is published openly on this site as proof of practice. Year-over-year biomarker trajectories live inside the Inner Circle, where the conversation can be specific without becoming generalized health advice.

What I now actually do

Over enough cycles, you stop using whatever can comes off the shelf and start optimizing the small variables that compound. A few things I’ve settled on after iteration:

• Sardines in brine, drained. Not in olive oil. Cans labeled “in olive oil” usually contain commodity blended or refined oil — fine eating, but not what I want loading my fat and polyphenol intake during a 5-day fast. Brine-packed sardines drain cleanly and let me control what fat shows up on the plate. (The packing-media analysis covers the EVOO vs refined-oil distinction in detail — see the packing media page.)
• My own single-source EVOO, added at home. A specific producer, a specific harvest, traceable polyphenol content. Single-source / single-estate EVOO is almost always higher in polyphenols than the blended supermarket oil that ends up in cans, even premium-branded cans. Blends are convenient; single sources are honest. The polyphenol load on a 5-day cycle is a non-trivial slice of what the protocol is doing — see the EU 432/2012 polyphenol claim and the regulatory background on the packing-media page.
• Oil-to-sardine ratio, calibrated by feel. I’ve experimented with this across many cycles. Too little EVOO and the cycle feels under-fueled by the third day; too much and the body-composition signal at the end softens. I won’t prescribe a number — body weight, training load, and starting metabolic state all move it — but the pattern that works for me is more EVOO than the equivalent oil-packed can would deliver, calibrated to feel rather than measured. Worth finding your own across four to six cycles.

None of this is gated knowledge — the public buying guide and packing-media analysis cover the science. What members get inside the Inner Circle is the iterated, year-over-year version: which producer I’m currently buying from, what changed in the brand spec sheet this year, and the practitioner data on how ratio choices shake out across cycles.

Why build this now

Twenty-plus cycles in, the protocol stopped being mine. Everything I cared about — the mechanism literature, the brand-by-brand sourcing detail, the refeed lessons, the women’s-cycle adaptations my partner has been testing alongside me — was scattered across notebooks, spreadsheets, and Notion pages. Two things converged: nobody was building the resource I would have wanted ten years ago, and the right tools to build it (a focused community on Skool, a Vercel-hosted research library, an MDX-driven citation graph) finally existed at the right cost.

The trigger wasn’t a moment. It was running out of reasons to defer.

The boundaries of this work

I am not a medical professional. Nothing on this site is medical advice. Everything I publish is either backed by primary sources (linked, with the strength of evidence noted) or labelled as personal practice. The Safety page spells out who should not attempt this protocol — read it first.