Eat on a consistent schedule

Keep meals — especially their timing window — roughly stable day to day.

Why it works

Beyond the master clock, peripheral clocks in organs like the liver and gut are entrained partly by when you eat. Erratic or very late eating can desynchronize these peripheral clocks from the central one, and late large meals also raise core temperature and digestion when the body is preparing for sleep.

How to do it

1. Keep meals within a fairly consistent daily window rather than grazing at random hours.
2. Avoid large meals close to bedtime; finish eating a couple of hours before sleep.
3. If you shift your schedule, shift meal timing with it to help the clock follow.

Evidence

Meal timing acting as a zeitgeber for peripheral clocks is supported by circadian research, much of it from animal models and a growing body of human time-restricted-eating studies. (observational)

Human evidence on meal timing is younger and less settled than the light literature; effect sizes and "best" windows are still debated. Treat as a sensible default, not a precise prescription.

Sources

• Wehrens et al. (2017), meal timing regulates the human circadian system, Current Biology

Common mistake

A large late-night meal as the day’s main calories — convenient, but it pushes digestion and temperature the wrong way at bedtime.