AGUANTE

Most people have never once been hungry on purpose.

You're about to find out how much of your life was built around avoiding it.

Why this exists

Every other fasting app counts down to a number that was made up.

Open any of them and you will find a timer marching toward autophagy at 16 hours. There is no primary human source for that hour. Not a weak one — none. Here is where it actually came from:

2016
Ohsumi wins the Nobel for the autophagy machinery — in yeast. Zero human timing data.
Alirezaei 2010
The paper everyone cites for "profound neuronal autophagy" — mice, measured at 24 and 48 hours.
The compression
Someone reasoned down from mouse hours to a human number. Mice run roughly 10× faster metabolically, so the correction should push human thresholds later, not earlier.
Marketing
16 was chosen because 16:8 was already popular.

And the human studies point somewhere between ambiguous and the wrong way. A 72-hour fast raised one autophagy marker 30% — and raised p62 10% at the same time, which is the signature of blocked flux, not active. A 36-hour study saw all three markers fall. The authors of the first one said outright they could not interpret it.

The honest reason this is so hard to measure: autophagy is a flux, not a level. The usual marker reads high both when the conveyor belt is racing and when it is jammed. Telling those apart requires a drug you cannot give a living person — so human flux data exist only for white blood cells in a dish. It is also tissue-specific. Liver responds; muscle largely doesn't.
The second one

The ketosis badge is in the wrong place too.

Sample blood ketones every six hours through a long fast and the curve is not a ramp. It is flat, and then it is not.

0%
Median change in blood ketones from hour 12 to hour 18
+333%
Across hours 18 to 36 — after the badge has already fired
−0.33%
Body weight versus ordinary dietary advice, 2026 Cochrane review

That flat stretch — hour 12 to 18 — is exactly where the industry puts its "ketosis begins" badge. 16:8 is a perfectly good protocol. It is not a ketosis protocol, and we think saying so is more interesting than a fake milestone.

The last number is the one nobody in this category prints. We are not selling you weight loss, because the evidence will not carry it, and you would find out in eight weeks.

What you get instead

Twelve milestones. Every one graded, in the open.

Each stage carries a visible confidence chip — how good the evidence actually is, shown to you rather than hidden behind a progress ring. Nothing below grade B ships. There is no autophagy hour and no autophagy gauge, because we cannot put a number on it honestly.

Hour 14 is built deliberately as the moment the app tells you what the other apps are doing.

Hunger arrives in waves of 20 to 60 minutes, locked to the times you habitually eat. It is not a fuel gauge. It is a schedule you learned.

That is the thing fasting is genuinely best at, and it is what this app is built around: you find out how much of your day is running on triggers you did not choose. Every crash in our research corpus happened during idleness, not exertion — one man sailed through twenty hours and cracked the second he sat down in a restaurant. So the hunger tool is a twenty-minute walk, not a motivational quote.

What it refuses to do

Nothing in here rewards a longer fast.

The tools

Built for the parts that are actually hard.

🧂

Electrolyte calculator

Bodyweight, hours in, sweat and keto adaptation — answered in teaspoons of table salt, because that is the unit you can act on. Deliberately lower than what you will read online, and it shows you why.

🚶

Ride the wave

A twenty-minute tool for the moment you want to quit. Walking is the intervention, because walking is what actually worked in the corpus.

Milestone catch-up

Put the phone down for ten hours and it tells you what you crossed while you were away, instead of pretending it never happened.

🫁

Guided breathing

Six breaths a minute and a physiological sigh — the two that won their head-to-heads. Box breathing and 4-7-8 lost theirs, so they are not here.

21-day keto ramp

Get the hard part over with before the fast. Sodium loss peaks on days one to four and settles by about day fourteen — so it happens on a Tuesday instead of during hour 30.

Cycle planning

Which week you are most likely to finish the fast you planned — framed as difficulty, never as chemistry. No trial has ever fasted women in one phase and compared it to another, and the tool says so.

Your data

No account required. No tracking. Your data, your device.

Everything stays on your device. There is nothing you have to sign up for, no analytics, and no third-party SDK watching you fast. If you ever want your history on a second phone, an account is there to switch on — and the app works exactly the same without one. You can export the whole history to a file whenever you want, and import it back.

It installs to your home screen and works with no connection at all.

Both languages

Escrito dos veces. Never translated.

Every word exists twice, written natively in English and Spanish to the same intent — not run through a translator. Where Spanish has the better idea, the Spanish wins and the English gets rewritten to match. A brand whose whole claim is honesty cannot ship calqued sentences.

The research behind it is public inside the app: 13 documents, roughly 97,000 words, around 500 sources, and five long-form articles that show their work.

Price

Free, and finished.

Not a trial, not a demo, not a teaser with the good parts locked. The timer, all twelve stages, the safety gate, the electrolyte doses, the coach, the cycle tool, the planning, the breathing, every article, both languages, and your data exported whenever you want it.