OBJECTIVE: Jet lag is common place amongst long haul cabin crew. Timed food has been shown to reset the circadian rhythm in rodents. Implementation intentions have been used to change eating behaviour. Meal times could therefore be used as a countermeasure to reduce jet lag and improve alertness in long-haul cabin crew through forming an implementation intention to improve the regularity of meals on days off.
DESIGN: 60 long-haul crew took part in a randomized controlled trial, with two conditions: forming an implementation intention to eat regular meals on days off versus no implementation intention. Pre-intervention measurements were taken at baseline (before a long-haul trip) and post-intervention measures were taken on the first and second days off post-trip. MAIN OUTCOME MEASURES: Subjective jet lag (unidimensional and multidimensional) and objective alertness (Psychomotor Vigilance Task (PVT)).
RESULTS: Mixed ANOVA showed a significant condition x time interaction for unidimensional jet lag but not for multidimensional jet lag and objective alertness. In particular, the formation of an implementation intention to alter meal times resulted in a reduction of unidimensional jet lag.
CONCLUSION: Implementation intentions can be used to alleviate jet lag in long-haul crew through promoting a change in meal times.