OMAD:
one meal a day.

Updated October 3, 2026 · General information, not medical advice.

What OMAD looks like

OMAD (one meal a day) is often written as 23:1: about 23 hours fasting and about 1 hour to eat. Your one meal is usually lunch or dinner. If you eat at 6 PM and finish by 7 PM, your next meal is at 6 PM the following day.

Example OMAD day

• Morning: water, black coffee or plain tea.
• Afternoon: keep going — this stretch is usually the hardest for new OMAD folks.
• 6–7 PM: your meal. Plan it ahead so it’s a full, balanced plate rather than whatever is fastest.
• 7 PM: start the timer. Your next fast is already running.

Working up to OMAD

OMAD is a big step from a normal eating pattern, so most people work toward it instead of starting there. A common path: get comfortable with 16:8, then 18:6 and 20:4, and only then try an OMAD day or two a week. It’s fine to go back to a longer eating window whenever OMAD doesn’t feel right.

Tracking OMAD with PBros

OMAD (23:1) is a one-tap preset in PBros. Start it when you finish your meal and you’ll see your live fasting time and the exact time your fast ends, on your iPhone, Home Screen widget, Lock Screen and Apple Watch. Longer 36h and 72h options sit behind a confirmation with a caution, on purpose.

Track OMAD with PBros’ 23:1 presetOne-time $4.99 · No subscription · No ads · No account

FAQ

How many hours is OMAD?

Usually about 23 hours of fasting with a 1-hour eating window, written as 23:1.

Is OMAD the same as 20:4?

No. 20:4 gives you a 4-hour eating window, often with two meals. OMAD is one meal in about an hour.

Can I do OMAD only some days?

Yes. Many people mix OMAD days with 16:8 or 18:6 days. PBros lets you pick a preset each time you start.

Is PBros a subscription?

No. PBros is a one-time $4.99 purchase. No subscription, no ads, no account.

Related guides

PBros is a timer and reminder app. It doesn’t diagnose, treat or give medical advice. For adults 18+.