23:1 intermittent fasting
A 23-hour fast with a strict 1-hour eating window — closely related to OMAD but with a fixed one-hour limit.
23h
Jejum
1h
Janela de alimentação
Horário de exemplo
Eating window opens at 6:00 PM
Start your first meal of the day.
Eating window closes at 7:00 PM
Finish your last meal for the day.
Fast until 6:00 PM the next day
23-hour fasting window begins.
Para quem é adequado
- Experienced fasters seeking a structured, strictly time-limited single-meal protocol
- People who practise OMAD and want to apply a precise 1-hour eating window
- Those comfortable with OMAD who prefer a clearly defined time boundary
Pros and cons
Prós
- A strict 1-hour window provides a clear, unambiguous eating boundary
- Shares the simplicity of OMAD — one eating occasion per day
- May appeal to people who find the flexibility of 'OMAD with up to 2 hours' harder to maintain
Contras
- One hour is a very short window in which to eat a complete, nutritious meal calmly
- Eating too quickly due to time pressure may contribute to digestive discomfort
- Extremely restrictive and not appropriate for people new to fasting
Perguntas frequentes
- What is the difference between 23:1 and OMAD?
- 23:1 specifies exactly a 1-hour eating window within a 23-hour fast. OMAD (One Meal a Day) is the broader concept of eating one meal per day, and some OMAD practitioners allow a window of up to 1.5–2 hours rather than a strict 60 minutes. In practice, 23:1 is the strictest version of OMAD.
- Is a 1-hour eating window enough time to eat a full meal?
- A single hour is sufficient time to eat one complete meal, though eating slowly and mindfully can be challenging under a strict time limit. Many 23:1 practitioners prepare their meal in advance so they can focus on eating rather than cooking during the window.
- How does 23:1 compare to extended fasting?
- 23:1 is a daily fasting protocol — a full 23-hour fast each day followed by a 1-hour eating window. Extended fasting typically refers to multi-day fasts (e.g., 24, 36, or 48 hours). 23:1 is repeated daily rather than being an occasional longer fast, and it always includes a daily eating occasion.