To adjust to jet lag or circadian disruption, which combination is most effective?

• A. Light exposure only
• B. Meal timing only
• C. Routine only
• D. Light exposure, sleep timing, meal timing, and routine

Answer: (D)

Adjusting to jet lag works best when several time cues are aligned to shift your internal clock together. Light exposure is the primary signal the brain uses to reset the central circadian clock, so timing bright light can move your clock toward the new time zone. Pair that with deliberate sleep timing to lock in a new sleep-wake schedule, which helps your body settle into the destination’s day-night pattern. Meal timing matters too, because when you eat can reset peripheral clocks in organs like the liver, reinforcing the new schedule across the body. Maintaining a stable daily routine further supports a smooth and sustained adjustment by reducing drift between cues. Relying on just one cue often yields only a partial shift and can leave you with lingering misalignment, whereas combining light, sleep timing, meal timing, and routine creates a cohesive, faster, and more complete adaptation.