How many hours is OMAD?

OMAD — one meal a day — is roughly a 23-hour fast with a 1-hour eating window. The exact number depends on how long your single meal takes; FastHQ counts the real interval rather than assuming a round 23:1.

FastHQ is built for exactly this: a precise, no-nonsense timer that counts your fast to the second, shows the metabolic phase you are in, and logs every fast — without streaks, badges, or nag screens. OMAD is a Pro protocol.

Does OMAD reach ketosis and autophagy?

A ~23-hour fast spends real time in ketosis (which typically begins ~18h) and reaches the edge of the autophagy band that FastHQ marks from ~24h. The autophagy timing is a conservative model, not a measurement — see the phase timeline.

Is OMAD safe to do every day?

Many people run OMAD daily, but it is demanding and makes it harder to hit protein and micronutrient targets in one sitting. It is not for everyone — check with a doctor first, especially if you are pregnant, diabetic, underweight, or have a history of disordered eating.

OMAD: one meal a day, timed precisely

OMAD — one meal a day — is exactly what it says: you eat once, then fast until the next day. In practice it is a fast of roughly 23 hours with a one-hour eating window. It is the most demanding of the daily protocols and the one that spends the most time deep in the fasted-state phases.

How to run an OMAD fast

Choose your one meal — most people pick dinner — and make it a complete, substantial plate.
Start the timer when you finish eating. FastHQ counts from the exact second.
Fast for roughly 23 hours. Water, black coffee, and plain tea through the day.
Eat and log. Open your window, eat, stop the timer.

FastHQ counts the real interval, not an assumed 23:1 — if your meal takes 50 minutes, that is what it logs.

What OMAD reaches metabolically

Because an OMAD fast runs ~23 hours, it moves well past where the shorter protocols stop on the phase timeline:

deep into ketosis (which typically begins ~18h), and
up to the edge of the autophagy band, which FastHQ marks conservatively from ~24h.

A word of honesty: the autophagy number is a model, not a measurement, and human evidence for a precise hour is thin. OMAD gets you close to that band most days — it does not guarantee a specific cellular outcome.

Who OMAD is for

OMAD suits experienced fasters who already run 16:8 or 18:6 comfortably and want a simple, single-meal structure. It removes meal-planning decisions: there is only one.

The trade-off is real. Eating a full day’s nutrition in one meal is hard — protein and micronutrients especially. It is not a beginner protocol, and it is not for everyone. Check with a doctor first if you are pregnant or breastfeeding, diabetic or on medication, underweight, or have any history of disordered eating.

Common mistakes

Under-eating. One meal still has to cover your day. OMAD is a timing pattern, not a license to crash your intake.
Starting cold. Work up through 16:8 and 18:6 first.
Chasing autophagy claims. Treat the phase bands as a guide, not a promise.

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