When to stop eating, and when to start again.
Pick a protocol and the time your last meal ends. You get your eating window and the hour each body stage typically begins — the same hours the Healthness timer uses.
- Fast ends
- 12:00next day
- Eating window
- 12:00–20:00
Your fast
- 20:000 h
Anabolic
Your body is digesting your last meal.
- 00:00+14 h
Catabolic
Stored glycogen typically becomes the main fuel.
- 08:00+112 h
Fat burning
Fat stores typically become a primary energy source.
- 12:00+116 h
Ketosis
Ketones typically rise as a fuel source. Reached as the fast ends.
- 12:00+116 h
The fast ends — time to eat.
- 20:00+124 h
Autophagy
Starts 8 h after this fast ends.
Body stages, hour by hour
What the body typically does as a fast goes on. It varies from person to person; these are the hours the app’s timer uses.
0–4 h
Anabolic
During the first few hours after eating, the body typically absorbs nutrients and uses glucose for energy.
4–12 h
Catabolic
Once digestion finishes, the body commonly switches to drawing on stored glycogen for energy.
12–16 h
Fat burning
When glycogen reserves run lower, the body commonly increases lipolysis — releasing stored fat for fuel.
16–24 h
Ketosis
Extended fasting commonly leads to ketone production from fat metabolism. Levels vary widely between individuals.
24–48 h
Autophagy
Longer fasts have been associated with autophagy — the cellular process of recycling damaged components. Research is ongoing.
48 h +
Deep ketosis
Fasts beyond 48 hours are advanced and should be undertaken only with appropriate guidance.
Every protocol, one page each
- 13:1113 h fasting · 11 h eatingA gentle starting protocol.
- 14:1014 h fasting · 10 h eatingAn easy daily reset.
- 16:816 h fasting · 8 h eatingThe most popular intermittent fast.
- 18:618 h fasting · 6 h eatingA focused six-hour eating window.
- 20:420 h fasting · 4 h eatingAdvanced — one tight eating window.
- OMAD (23:1)23 h fasting · 1 h eatingOne meal a day.
Healthness runs the timer for you.
13:11, 14:10, 16:8, 18:6, 20:4, OMAD or your own window. An hour-by-hour body-stages sheet tells you where you are — anabolic, catabolic, fat burning, ketosis, autophagy — in plain language, at the moment it becomes true. Rate your energy in one tap when it ends, and the pattern tells you which windows actually suit you.
Is Healthness medical advice? No. It is an educational tracking tool. Fasting is not right for everyone — if you are pregnant, diabetic, on medication, or have a history of disordered eating, talk to your doctor before changing how you eat.