How intermittent fasting plans work
Intermittent fasting (time-restricted eating) means eating all your food within a set window each day and fasting for the rest. The first number is the fasting hours, the second the eating hours: 16:8 means 16 hours of fasting and an 8 hour window.
| Plan | Fast | Eat | What it is like |
|---|---|---|---|
| 12:12 Circadian | 12 h | 12 h | An easy start: mostly just no late-night snacking. |
| 14:10 Early TRE | 14 h | 10 h | A practical everyday pattern, for example 9 am to 7 pm. |
| 16:8 Intermittent | 16 h | 8 h | The most popular plan, often skipping breakfast or dinner. |
| 18:6 Lean Gains | 18 h | 6 h | A short eating window. Harder to fit enough protein in. |
| 20:4 Warrior | 20 h | 4 h | Very short window, usually one main meal. Not for beginners. |
Example: on 16:8 with a first meal at 11 am, your window runs from 11:00 am to 7:00 pm, and your last meal starts around 6:30 pm.
An Indian 16:8 day
- Morning: water, black tea or black coffee. No milk or sugar until the window opens.
- 11 am, first meal: a protein-led brunch such as besan chilla with curd, eggs with a roti, or poha with peanuts and a glass of milk.
- Around 6:30 pm, last meal: dal, two rotis, a big plate of sabzi and some paneer or chicken.
Fasting does not cancel out calories. The research is clear that time-restricted eating mostly works by making it easier to eat less, so pair your window with a calorie target and enough protein.
The Calo AI app has a fasting timer for all five plans that keeps running if you close the app, with a history of your fasts.