HOME / FASTING / 16:8 VS OMAD

16:8 or OMAD

Around seven hours separate them, and those hours change almost everything about how the day feels. One stage difference, two very different weeks.

Here is what each one reaches, what each one asks, and how to tell which suits you.

16:8

ENDS IN FAT MOBILISATION

Sixteen hours fasting, eight to eat

Usually breakfast dropped and two meals in the afternoon and evening. Eight hours is enough room that no meal has to be rushed and nothing needs explaining to the people you eat with.

Meals Two, comfortably

Hard hour Around 14, late morning

Stage reached Fat Mobilisation

The 16:8 guide →

OMAD

ENDS IN KETOSIS ENTRY

One meal a day, one hour to eat it

Everything in a single sitting. The clock is the easy part; getting a full day of food into one meal, and being free at the same hour every evening, is the demanding part.

Meals One, large

Hard hour Around 14, then it eases

Stage reached Ketosis Entry

The OMAD guide →

One stage apart

16:8 stops inside Fat Mobilisation, OMAD inside Ketosis Entry

0-3hFed State

3-8hEarly Fasting

8-14hGlycogen Depletion

14-18hFat Mobilisation

18-24hKetosis Entry

24-48hFat Burning

Both fasts pass through the same first four stages. OMAD adds one more, and its extra hours are spent in the stage where ketone production becomes meaningful and hunger often drops. That is the whole physiological difference between them.

Where they really differ

The stage gap is small. The lifestyle gap is not.

One stage of difference is worth less than it sounds. What separates these two in practice is what they do to your evenings and your meals.

EATING

Two meals or one

A full day of food in one sitting is harder than it sounds, and getting enough protein into a single meal takes planning. Eight hours lets you eat normally without thinking about it.

SOCIALLY

A window versus a slot

A dinner invitation fits inside eight hours almost regardless of the time. One hour has to be the hour, which makes OMAD the harder schedule to keep on an unpredictable week.

TRAINING

Where the hard session goes

Hard efforts want glycogen. An eight hour window gives you somewhere to put a session with food either side of it; a one hour window does not.

Choosing

Which one to pick

Pick 16:8 if your week is unpredictable

Eight hours absorbs a late meeting, a lunch out, or a dinner that moves. A schedule you keep on a bad week beats a stricter one you abandon.

Pick OMAD if you would rather not think about food

Some people find one decision a day simpler than three. If your evenings are reliably yours and you like large meals, the clock stops being the difficult part.

Work up to OMAD rather than starting there

Run 18:6 and 20:4 comfortably before going to one meal a day. Switching plans keeps your history intact.

Four questions to decide → Every daily schedule →

Burn's timer at 16 hours 22 minutes on a 16:8 fast, with the goal met

Burn's timer at 20 hours 9 minutes, the stage pill reading KETOSIS, the stage an OMAD fast finishes in

What the evidence supports

Time-restricted eating produces weight loss in controlled human trials, comparable to other approaches at matched intake. No trial establishes that a one hour window outperforms an eight hour one. Which pattern a person can sustain matters more than which is theoretically optimal. Claims here are drawn from peer-reviewed research and traced in our evidence policy.

Before you start either

Speak to your doctor first if you are pregnant or breastfeeding, have a history of eating disorders, manage diabetes, take medication timed to meals, or are under 18. A one meal a day pattern makes it harder to meet your needs, so it deserves that conversation more than a shorter window does.

Try one, then try the other

Both are built into Burn, and switching between them keeps every fast you have already logged.

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