Once 16:8 feels comfortable, the obvious next question is whether to tighten the window to 18:6. Both are excellent; the right one depends on your routine and how your body responds.
16:8 is a 16-hour fast and an 8-hour eating window — say, noon to 8pm. 18:6 stretches the fast to 18 hours and shrinks eating to 6 — say, 1pm to 7pm. The only real difference is two hours, but those two hours change how the schedule feels.
16:8 is the most popular protocol for good reason: an eight-hour window comfortably fits two or three meals, so it rarely disrupts social life or family dinners. For most people, most of the time, it’s the one to build the habit on.
18:6 gives a longer daily fast while still allowing two solid meals. People move to it when 16:8 feels effortless and they want a bit more from the same routine. The main trade-off is a tighter window, which takes a little planning so you don’t under-eat.
Start on 16:8. If you hold it easily for a couple of weeks and want more, push your first meal an hour later to reach 18:6. If the tighter window leaves you rushing meals or overly hungry, drop back — consistency at 16:8 beats a stressful 18:6. Our free fasting timer supports both, so you can experiment without losing your streak.
Pick your window, start the clock, and build the streak. No sign-up to try.
Open the timerNot dramatically. What matters most is consistency and your overall diet. A tighter window can help some people eat less, but only if they don’t compensate with larger meals.
Absolutely — many people run 16:8 on busy or social days and 18:6 when it suits. Flexibility helps you keep going.