Article ID: 2017-0047
This study examined the impact of eating during simulated night shift on performance and subjective complaints. Subjects were randomized to eating at night (n=5; 23.2±5.5y) or not eating at night (n=5; 26.2±6.4y). All participants were given one sleep opportunity of 8h (22:00h-06:00h) before transitioning to the night shift protocol. During the four days of simulated night shift participants were awake from 16:00h-10:00h with a daytime sleep of 6h (10:00h-16:00h). In the simulated night shift protocol, meals were provided at ≈0700h, 1900h and 0130h (eating at night); or ≈0700h, 0930h, 1410h and 1900h (not eating at night). Subjects completed sleepiness, hunger and gastric complaint scales, a Digit Symbol Substitution Task and a 10-minute Psychomotor Vigilance Task. Increased sleepiness and performance impairment was evident in both conditions at 0400h (p<0.05). Performance impairment at 0400h was exacerbated when eating at night. Not eating at night was associated with elevated hunger and a small but significant elevation in stomach upset across the night (p<0.026). Eating at night was associated with elevated bloating on night one, which decreased across the protocol. Restricting food intake may limit performance impairments at night. Dietary recommendations to improve night-shift performance must also consider worker comfort.