How the evidence is written
What the texts describe
Each body stage and explainer card says what studies measured, not a reading of your own body. Timing varies from person to person.
The app and this site read the same register: one list of the stages and explainer cards, each with its text, its confidence word and its papers. The stage and card pages here are built from that register, so they say what the app says, word for word.
The confidence words
Every stage and card carries one of four words, drawn with a small circle filled to match, and beside it where the evidence comes from.
- High Measured in humans
- Direct measurement in healthy adults across several studies.
- Moderate to high Measured in humans
- Between high and moderate. The register gives this word no definition of its own; its circle is three quarters full.
- Moderate Measured in humans
- Fewer or smaller studies, or wider variation between people.
- Low Animal or indirect evidence
- Used only for explainer cards, which is why autophagy is never a stage.
The evidence source goes with the word, not with each paper: High, Moderate to high and Moderate are always shown as measured in humans, and Low always as animal or indirect evidence. These short definitions are the whole of the written rule; no numeric score sits behind the words.
How papers are chosen and cited
- Studies in people first. Every stage cites studies in people, and every stage is shown as measured in humans.
- Animal studies only where the text names them. The Autophagy card cites a study in mice (Mizushima 2004) and one of mouse and human tissue (Chaudhary 2022), and its text says the timing comes from mice and that human studies give mixed results. The Longevity and body size card says fasting extends lifespan in laboratory animals, and that there is no evidence it does so in humans.
- Guidelines as guidelines. Two clinical guidelines are cited: ASPEN 2020, consensus recommendations on refeeding syndrome, and NICE CG32, on nutrition support for adults. They sit on Refeeding and Prolonged fast.
- Reviews named as reviews. Pooled evidence is named for what it is, such as the Cochrane 2021 review and the BMJ 2025 network meta-analysis of 99 trials.
Each stage and card lists its papers by first author and year, linked to the paper's PubMed record or, for NICE CG32, to NICE's own page. Titles, journals and dates are taken from PubMed and NICE, not typed by hand. Every paper is on the Sources page, with the stages and cards that cite it.
Who writes it
The stage and card texts, and this site, are written and published by Serhat Dereli, a sole trader trading as Nesteia, Bromley, UK.
The texts were drafted with the help of AI tools, working from the cited papers, and are published under the publisher's responsibility.
The register has not yet been independently reviewed by a clinician. Every claim links to its source, so you can check it against the paper yourself.
Evidence editions
The register is versioned. An evidence edition is one numbered version of it: the stages, the explainer cards, their confidence words and their papers. The app shows the edition it carries at the foot of Settings, as "Evidence edition 1.0", and each stage and card page here shows the same edition with the date the register was last updated.
This is evidence edition 1.0, last updated . That date changes only when the register's content changes. Changes to the register are listed on What's new.
Report an error
If a stage or card says more than its paper supports, cites the wrong paper, or links to the wrong place, write to serhatdereli@icloud.com. Say which page and which line, and which paper if you can.
This address is for the evidence and the site; it cannot give medical advice. Your GP or NHS 111 can.
Corrections
None published yet. When a stage or card is corrected, the correction will be listed here with its date and what changed, and on What's new.
Not medical advice
Nesteia describes what studies measured in healthy adults. It is not a medical device, medical advice or a substitute for advice from your doctor. Do not fast if you are under 18, pregnant or breastfeeding, underweight, have a history of an eating disorder, or have been advised against it.
Stop and seek help if you feel unwell. The signs to stop for are listed under Stop signs on the safety page.