Revised Second Edition, 2026
Spiral Staircase: How Your Ancient Body Navigates the Modern World
Your body was built for a world that no longer exists.
A practical book about the whole body and the mind: what each part of you evolved to expect, what modern life hands it instead, and what to do about the gap, in minutes, steps, servings and rooms rather than laboratory units.
Each chapter follows the same path. Evolution says what your body expects; the trials say how much. Then comes the protocol, opening with a short Start here list of the one to three actions that matter most, with versions for night shifts, a tight budget, stiff joints and the years around menopause. Every recommendation carries a grade, strong, probable or emerging, and popular claims are tested in boxes headed What you've heard.
Start with Chapter 1
The short version
The five things that matter most, ranked, each with a dose and a grade.
The appendix
The 30-day protocol
Four weeks, one layer a week, and 7 tracks for particular lives.
What you've heard
39 claims, graded
Seed oils, cold plunges, mouth taping, testosterone and more, each with its verdict.
The five things that matter most
Chapter 1 ranks them, and the rest of the book explains them. Each comes with a dose and a grade.
- 1
Don't smoke, and drink little or nothing
no cigarettes, with medication or a regulated e-cigarette to get there. Alcohol, if any, kept low; two or fewer standard drinks a week is the low-risk band.
Grade: no smoking StrongEvidence grade: Strong. Multiple randomized controlled trials, or consistent large cohort studies with a well-understood mechanism.. Little or no alcohol ProbableEvidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials. (StrongEvidence grade: Strong. Multiple randomized controlled trials, or consistent large cohort studies with a well-understood mechanism. for cancer).
- 2
Move: walk, lift, and hurry now and then
walk toward seven or eight thousand steps a day, from wherever you are; two strength sessions a week of about half an hour; a few short bursts of hard effort a day.
Grade: walking StrongEvidence grade: Strong. Multiple randomized controlled trials, or consistent large cohort studies with a well-understood mechanism.. Strength twice a week StrongEvidence grade: Strong. Multiple randomized controlled trials, or consistent large cohort studies with a well-understood mechanism.. Short bursts ProbableEvidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials..
- 3
Eat: subtract first
swap the meals you eat most often for versions built from ingredients, then add plants and legumes.
Grade: ProbableEvidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials. (one small ward trial; weaker long-term evidence).
- 4
Sleep: keep regular times
the same wake time every day, weekends included; outdoor daylight early; a dark bedroom.
Grade: ProbableEvidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials. for regular wake times; EmergingEvidence grade: Emerging. Early, small, animal-only, or actively contested. for the health effects of a dark bedroom (one small laboratory study).
- 5
People: an inner circle you actually see
name three to five people and put recurring, in-person contact with them in the calendar; add one standing weekly thing done with others.
Grade: ProbableEvidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials. for close ties; EmergingEvidence grade: Emerging. Early, small, animal-only, or actively contested. for the standing weekly thing.
Prologue
The Staircase
In 1966, five healthy young men in Dallas spent three weeks in bed. When they got up, they had lost more aerobic fitness than the next three decades of aging would take from them.
Nothing had been done to them. Something had been taken away: the daily signal that a body is in use. Take away a signal and the system that reads it drifts, fast. Restore it and the system answers, often within weeks.
Where to start
The Prologue's own map from a problem to a chapter.
- Sitting all day, a sore back or knees, blood pressureChapter 3
- Losing strength, bone and balanceChapter 4
- Weight, blood sugar and what to eatChapter 5
- Gut trouble, allergies and infectionsChapter 6
- Daylight, sun and vitamin DChapter 7
- Poor sleep and night shiftsChapter 8
- Hot flushes, cold water and saunaChapter 9
- Loneliness, phones and focusChapter 11, Chapter 12
- Stress, low mood and griefChapter 13, Chapter 14
- Smoking and drinkingChapter 1, Chapter 5, Chapter 14
- Periods, contraception, PCOS and menopauseChapter 15
- Testosterone, prostate, PSA and erectionsChapter 16
- Hearing, screening and agingChapter 10, Chapter 16
Contents
The Short Version
If you read only two chapters, read these. The first tells you what to do; the second tells you why you can trust it.
- Chapter 1The Short VersionStart here: If you smoke, quit with help; Walk more than you do now, toward seven or eight thousand steps a day; Lift twice a week, about half an hour each time; Swap the ultra-processed meals you eat most often.4 graded recommendations · 29 notes
- Chapter 2Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.What Your Body Expects, and How to Trust This BookStart here: Settle the dairy question with a two-week trial, not a DNA kit; Check one thing you already pay for (a habit, not a treatment); If a drink turns your face red, whatever your background, treat it as a stop sign.3 graded recommendations · 9 claims tested · 28 notes
The Body That Moves
Part One gave the short version. Part Two begins with the oldest signal of all, a body being used: on foot, under load, day after day.
- Chapter 3Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.The Body That WalksStart here: Walk every day, building toward 7,000 to 8,000 steps from wherever you are; Break up sitting every half hour; Swap your table salt for a potassium-enriched salt substitute.3 graded recommendations · 3 claims tested · 30 notes
- Chapter 4Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.Load, Strength and BoneStart here: Two strength sessions a week, 20 to 30 minutes each; Reach the daily protein range for your age; Over 50, or told you have low bone mass: add heavier and impact loading, learned in person.3 graded recommendations · 2 claims tested · 26 notes
The Body That Eats
Part Two followed the body that moves. Part Three follows food into it: what goes on the plate and in the glass, and the microbes waiting in the gut to meet it.
- Chapter 5Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.EatStart here: Cut the ultra-processed share first, beginning with sugary drinks and processed meat; Build meals on plants, legumes, and minimally processed protein and fats; Drink to thirst.3 graded recommendations · 3 claims tested · 37 notes
- Chapter 6Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.The Gut That Expects DirtStart here: Eat more fiber, from many kinds of plant; Add one serving of fermented food with live cultures a day, and build up if you like it; Parents of babies: introduce peanut and well-cooked egg early, and keep them in the diet.3 graded recommendations · 4 claims tested · 27 notes
The Body That Reads Signals
The next four chapters follow the signals that place a body in time and space: light and dark, the sleep that light schedules, heat and cold, green space and quiet. Blur one of those signals and the system built to read it drifts.
- Chapter 7Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.Light and DarkStart here: Get outdoor daylight early in your day, roughly 10 to 30 minutes; Dim the last two to three hours before bed; Get children outdoors about two hours a day; less still helps.3 graded recommendations · 3 claims tested · 28 notes
- Chapter 8Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.SleepStart here: Get up at the same time every day, weekends included; Make the bedroom dark, cool and quiet, with the phone charging somewhere else; If insomnia has lasted three months or more, ask for CBT-I before sleeping pills.3 graded recommendations · 4 claims tested · 29 notes
- Chapter 9Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.Heat and ColdStart here: Let your home move a little: cooler rooms in winter, and a bedroom that cools at night; End your shower with thirty seconds of cold, if you like it and your heart is healthy; Heat: a sauna or a hot bath, a few times a week, if you have access and enjoy it.3 graded recommendations · 3 claims tested · 24 notes
- Chapter 10Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.Green and QuietStart here: Spend about two hours a week somewhere green, including city parks; Protect your hearing from loud noise; Get a hearing test if you are over 50 or struggling to follow conversation.3 graded recommendations · 2 claims tested · 20 notes
The Social Animal
Other people are a signal too. Part Five follows the ones that come from company, from whatever competes for your attention, from stress, and from the wanting, loving, losing and meaning that fill a life.
- Chapter 11Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.The Social AnimalStart here: Name your three to five people, and schedule them; Join one standing weekly thing done with other people; Expecting or raising young children? Recruit helpers on purpose, before you need them.3 graded recommendations · 27 notes
- Chapter 12Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.Attention in the Age of the PhoneStart here: Charge the phone outside the bedroom; Turn off every notification that is not a person; Use AI like a spotter, not a stand-in, whenever you want to learn or keep a skill.3 graded recommendations · 2 claims tested · 20 notes
- Chapter 13Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.Stress and the MindStart here: Move most days, in whatever form you will keep doing; Practice slow breathing or mindfulness for five to ten minutes a day, or take an eight-week course; Talk to a clinician if low mood or anxiety lasts more than two weeks or gets in the way of work, sleep or people.3 graded recommendations · 3 claims tested · 30 notes
- Chapter 14Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.Wanting, Loving, Losing, MeaningStart here: Invest in the quality of your closest relationship, and get couple therapy if it is in trouble; Take on a recurring role, about two hours a week; If a substance or habit has a grip, change your surroundings, and ask about medicine alongside it; After a death, lean on people.4 graded recommendations · 2 claims tested · 32 notes
The Life Course
The chapters so far took the body apart signal by signal. Part Six puts it back on a clock, and for women the clock has landmarks of its own: the first period, pregnancy, the long transition out of fertility, and the decades after it. Chapter 16 then follows every body, women's and men's, into the second half of life.
- Chapter 15Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.Women's Bodies Across the Life CourseStart here: In the reproductive years, track your cycle as a vital sign; In perimenopause, take your symptoms to a clinician, because effective treatments exist; At every stage, lift.3 graded recommendations · 2 claims tested · 39 notes
- Chapter 16Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.Aging WellStart here: Keep up the five things in Chapter 1; Get the screenings due for your age and sex; Keep your strength and grip.3 graded recommendations · 3 claims tested · 41 notes
By topic
Each topic page gathers the chapters on one subject with their start-here actions, the reference topics behind them and every claim they grade.
Epilogue
The View from Here
In May 2026 I spent most of a week on a 9,000-acre property with about eighty observant Jewish families, for the festival of Shavuot. I was the only non-Jewish person there. Every meal was eaten together, and children ran in packs between the adults. For the holy days nobody used a phone. Using one was simply outside the frame, never an option a person weighed and declined.
I have been trying to build willpower against my phone for years, with the usual results. There, not once did I want it.
- Choose one day a week, or one evening, and take the phone out of itProbableEvidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.EmergingEvidence grade: Emerging. Early, small, animal-only, or actively contested.
- Put the missing signals back into that day on purposeProbableEvidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.
- Add phone-free times to ordinary daysEmergingEvidence grade: Emerging. Early, small, animal-only, or actively contested.
Plus the 30-day protocol, a glossary and a further reading list at the back. Read the protocol.
Two layers on this site
The book
The sixteen chapters as now sold, each with its opening, protocol, verdicts, card and every work it cites.
The reference library
The research the book was built from: 45 in-depth topic entries with 234 graded recommendations, a glossary, the corrections register and 2,315 sources. Open the library.
Formats
- Paperback · recommended$22.99
343 pages, sixteen chapters, every recommendation graded.
- Kindle$12.99
Searchable, with every chapter's notes a tap away.
- Hardcover$32.99
343 pages, for a copy that gets reopened.
- Paperback ISBN
- 9798176270860
- Hardcover ISBN
- 9798176268751
How it compares with ten well-known books · This edition and the first
Also available: the first edition
The earlier book: 34 chapters in 268 pages, cited but ungraded. It still sells, and the second edition corrects it in 71 places, all listed free on this site.
A spiral staircase is easier to climb than to descend. You do not have to go all the way back down.
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