16:8 fasting: your schedule, hour by hour.
16 hours of fasting and 8 hours of eating, every day. The most popular intermittent fast. Finish your last meal at 20:00 and you eat again at 12:00 the next day.
- 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.
Common 16:8 schedules
| Last meal ends | Eating window |
|---|---|
| 18:00 | 10:00–18:00 |
| 19:00 | 11:00–19:00 |
| 20:00 | 12:00–20:00 |
| 21:00 | 13:00–21:00 |
How far a 16:8 fast gets
The stages the app’s timer passes through before this fast ends. It varies from person to person.
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.
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.