Liver, pancreas, and gut have their own circadian rhythms tied to meal timing. Eating at local mealtimes from day one sends a coordinated "new day" signal — even if you are not hungry.
Eat the airline meal if it lines up with destination mealtimes. Skip it if it falls during destination night. Pack a backup.
A real breakfast within an hour of waking is one of the strongest non-light cues. Protein plus a small amount of carbs. Eat it in daylight if possible.
Finish dinner 2–3 hours before target bedtime. Skip alcohol on adjustment nights — it shortens latency but fragments sleep.
Mild dehydration mimics jet lag symptoms. Fasting protocols are mixed in evidence; the breakfast itself matters more than the fast.