What it actually is

Intermittent fasting restricts when you eat rather than what. The common versions are 16:8 — all meals inside an eight-hour window — and 5:2, where two days a week are heavily reduced. The honest summary of the research is that it works for the people it suits, mostly because eating in a shorter window tends to mean eating somewhat less overall, and that head-to-head against plain calorie reduction it does not consistently come out ahead. Whether it suits you is a real question and it's answerable from your own log.

Why this is hard to keep track of

  • Fasting apps track the timer, which is the part you already knew
  • The window drifts by twenty minutes a week and nothing notices
  • The first meal after a long fast is the one that decides the day, and it's unrecorded
  • After a month there's no way to tell whether the protocol or the season changed things

Worth recording

  • When the window opened and closed, roughly
  • What the first meal after the fast actually was
  • Energy and concentration through the fasting hours
  • Whether the evening ran past the window, and what was happening when it did

Cadence

A line per meal, plus the window when it's not your usual

In practice

Say it once, or photograph it

The entries most worth having are the ones made at the exact moment nobody wants to fill in a form. A sentence — typed, dictated, or replaced entirely by a photo of the plate — is a much lower bar, and it carries the context a calorie field would have thrown away.

Intermittent Fasting Chat

Broke the fast at half twelve, ate a lot — leftover curry and rice, then toast an hour later. Window was meant to close at half eight, ended up more like ten.

Called 4 tools

  • log_window(opened: "12:30", closed: "22:00", target_hours: 8)
  • log_meal(items: ["curry", "rice"], first_after_fast: true)
  • log_meal(items: ["toast"], at: "13:40")
  • compare_periods(metric: "window_length", window: "8w")

Logged. Your average window has gone from 8.2 hours in June to 10.4 this month, mostly at the evening end — 14 of the last 20 closed after half nine. First meals after the fast are also getting larger by your own descriptions.

Every figure here was counted from entries you made. The model chose which tools to call — it doesn't score the meal, estimate calories from a photo, or decide what any of it says about you.

And then ask

The question the log can answer

Months of entries hold real answers to the things you've been guessing at, and reading them properly has always meant a spreadsheet and a free evening — which is exactly what nobody has.

Ask in plain language. The answers come back with the counts behind them, including when those counts are too thin to mean anything yet — which is the more useful answer far more often than people expect.

Asking about the pattern Chat

Is this actually working, or am I just eating the same amount in less time?

Called 3 tools

  • get_history(topic: "intermittent-fasting", window: "6m")
  • find_pattern(group_by: "context")
  • compare_periods(metric: "entries")

Hard to say from windows alone, so here's what your log does show. On the 23 days you closed inside nine hours, you logged an average of 2.4 eating occasions. On the 19 days past ten hours, 3.6 — with the extra ones landing in the evening. Your weight trend is flat across both. That's consistent with the window mattering less than what's in it.

Counts and averages over your own entries, nothing more. Where the data is confounded or too thin, the answer says so instead of rounding it into a conclusion.

What it does

Set up around intermittent fasting

The same mechanics as everything else here, pointed at what actually matters for this one.

Log the protocol as you're living it

What you ate, in a sentence, plus whatever this particular protocol turns on — a window, a training day, a threshold. No spreadsheet to maintain.

The parts that drift

Windows stretch, thresholds creep, and the rule you're following in month three is rarely the one you started with. Drift is obvious in a record and invisible from inside it.

Whether it's actually doing anything

The question every protocol dodges. Answered here by comparing your own weeks against each other, rather than against a claim from a website.

Straight about the evidence

Where the research is strong we say so, and where a popular claim doesn't hold up we say that too. You can get the marketing version anywhere.

The weeks it slips are the useful ones

Adherence is what separates protocols that work from protocols that don't. The days it came apart, and what was happening on them, are the most informative entries in the whole log.

Something to review with someone

Several of these interact with medication. A real record of what you ate and how it went is what makes that a conversation rather than a guess.

The reason a lot of people start

Something to actually bring to the appointment

You get fifteen minutes, and the first question is always some version of "so what does a normal week look like?" — which nobody on earth can answer accurately from memory.

What this gives you: A record of what the protocol looks like in practice rather than on paper, which is what anyone reviewing it with you needs and what almost nobody has.

  • Export the date range you were asked about, as a file you can print
  • Photos alongside the entries, which say more than any description
  • Counts and timings rather than an impression of the worst week
  • Nothing shared anywhere unless you choose to share it

What it won't do

  • Score a meal, or sort food into good and bad
  • Estimate calories from a photo and present the guess as a number
  • Set you a calorie target, a macro target, or a weight
  • Run a streak you can break, or tell you that you've fallen behind
  • Comment on your body. The photos here are of food
  • Diagnose anything, or suggest that a pattern is a diagnosis

It's a notebook that can do arithmetic and answer questions about itself. Deciding what any of it means is a job for you and the people advising you.

Early access

Start with what you're already trying to hold in your head

Tell us what you've been trying to keep track of and we'll set it up with you — recording the thing that's actually useful, at a cadence that survives a bad week.

  • Founding accounts lock their price for life
  • No card, no trial clock, no notification designed to make you feel behind
  • Export everything you've logged, photos included, whenever you want

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Keep the record without it becoming another job

Founding pricing is locked for accounts opened during early access.

Founding accounts lock their price for life. No card required.