Building an OMAD schedule
OMAD, one meal a day, is a fasting schedule with roughly a 23-hour fasting window and a 1-hour eating window. You pick a single time each day to eat, fit the day's food into about an hour, and fast the rest of the time on water, black coffee or plain tea.
Picking your meal time
The best time is the one you can repeat. An early dinner, say 5:00 to 6:00 PM, leaves the evening free and means you are asleep for much of the fast. A midday meal suits people who are hungriest in the afternoon. Whatever you choose, keeping it within an hour or two of the same time every day is what makes OMAD sustainable.
OMAD next to the everyday protocols
OMAD is the far end of the same ladder as 16:8 and 20:4: a longer fast with a shorter window. If a full 23-hour fast feels like too much, 20:4 (a 20-hour fast, a 4-hour window) is the step before it. The fasting window calculator shows the eating time for each one from any last-meal time.
Keeping the schedule
A missed day is a missed day, not a failure. Pick the schedule back up the next day. Better Fasting tracks the streak and lets you set a gentler protocol for a day you know will not suit OMAD (a long dinner out, travel) so one exception does not reset the run.
A note on the research
This is general information about how the schedules work, not medical advice, and it makes no claims about weight or health outcomes. Talk to a clinician before changing how you eat, especially if you are pregnant or breastfeeding, take medication for blood sugar or blood pressure, or have a history of disordered eating.
For the evidence itself, peer-reviewed reviews of time-restricted eating include de Cabo & Mattson in the New England Journal of Medicine (2019) and a Nature Reviews Endocrinology review of circadian eating (2022). Guidance from a national health service or a registered dietitian is a good starting point.
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