title: It's not just what you eat but when: The impact of eating a meal during simulated shift work on driving performance.
abstract: Shiftworkers have impaired performance when driving at night and they also alter their eating patterns during nightshifts. However, it is unknown whether driving at night is influenced by the timing of eating. This study aims to explore the effects of timing of eating on simulated driving performance across four simulated nightshifts. Healthy, non-shiftworking males aged 18-35 years (n = 10) were allocated to either an eating at night (n = 5) or no eating at night (n = 5) condition. During the simulated nightshifts at 1730, 2030 and 0300 h, participants performed a 40-min driving simulation, 3-min Psychomotor Vigilance Task (PVT-B), and recorded their ratings of sleepiness on a subjective scale. Participants had a 6-h sleep opportunity during the day (1000-1600 h). Total 24-h food intake was consistent across groups; however, those in the eating at night condition ate a large meal (30% of 24-h intake) during the nightshift at 0130 h. It was found that participants in both conditions experienced increased sleepiness and PVT-B impairments at 0300 h compared to 1730 and 2030 h (p < 0.001). Further, at 0300 h, those in the eating condition displayed a significant decrease in time spent in the safe zone (p < 0.05; percentage of time within 10 km/h of the speed limit and 0.8 m of the centre of the lane) and significant increases in speed variability (p < 0.001), subjective sleepiness (p < 0.01) and number of crashes (p < 0.01) compared to those in the no eating condition. Results suggest that, for optimal performance, shiftworkers should consider restricting food intake during the night.
authors.affiliation: a Centre for Sleep Research, School of Psychology, Social Work and Social Policy, University of Australia , Australia.
authors.forename: Charlotte C
authors.initials: CC
authors.lastname: Gupta
authors.affiliation: a Centre for Sleep Research, School of Psychology, Social Work and Social Policy, University of Australia , Australia.
authors.forename: Jill
authors.initials: J
authors.lastname: Dorrian
authors.affiliation: a Centre for Sleep Research, School of Psychology, Social Work and Social Policy, University of Australia , Australia.
authors.forename: Crystal L
authors.initials: CL
authors.lastname: Grant
authors.affiliation: b School of Pharmacy and Medical Sciences, University of Australia , Australia.
authors.forename: Maja
authors.initials: M
authors.lastname: Pajcin
authors.affiliation: c Division of Health Sciences, University of South Australia , Australia.
authors.forename: Alison M
authors.initials: AM
authors.lastname: Coates
authors.affiliation: d Robinson Research Institute, Adelaide Medical School, University of Adelaide , Australia.
authors.forename: David J
authors.initials: DJ
authors.lastname: Kennaway
authors.affiliation: e Discipline of Medicine, Adelaide Medical School, University of Adelaide , Australia.
authors.forename: Gary A
authors.initials: GA
authors.lastname: Wittert
authors.affiliation: f Robinson Research Institute, Discipline of Medicine , Adelaide Medical School, University of Adelaide and South Australia Medical Research Institute (SAHMRI) , Adelaide , South Australia , Australia.
authors.forename: Leonie K
authors.initials: LK
authors.lastname: Heilbronn
authors.affiliation: b School of Pharmacy and Medical Sciences, University of Australia , Australia.
authors.forename: Chris B
authors.initials: CB
authors.lastname: Della Vedova
authors.affiliation: a Centre for Sleep Research, School of Psychology, Social Work and Social Policy, University of Australia , Australia.
authors.forename: Siobhan
authors.initials: S
authors.lastname: Banks
mesh_terms: D000328:Adult; D001334:Automobile Driving; D002940:Circadian Rhythm / Q000502:physiology*; D006801:Humans; D008297:Male; D062407:Meals; D017286:Polysomnography; D011597:Psychomotor Performance; D000073577:Shift Work Schedule; D012892:Sleep Deprivation; D013647:Task Performance and Analysis; D055815:Young Adult
keywords: Shiftwork; eating at night; nightshift; simulated driving; timed eating