The impact of meal timing on performance, sleepiness, gastric upset, and hunger during simulated night shift
Summary
This randomized crossover study tested whether eating at night affects alertness and well-being during simulated night shifts. Ten participants were assigned to either eat a meal at 1:30 a.m. or avoid food overnight while keeping total daily calories the same. Both groups experienced sleepiness at 4:00 a.m., but those who ate at night showed greater performance impairments, while those who avoided night meals had better vigilance but reported more hunger and some stomach discomfort.
Why It Matters For Night Shift Workers and Night Owls
This study shows that when you eat matters just as much as what you eat during night shifts. Late-night meals may worsen fatigue and slow reaction times at the most vulnerable point of the shift, while skipping food can help maintain alertness — though it comes with more hunger and mild stomach upset. For night workers, this suggests that adjusting meal timing — for example, shifting larger meals earlier in the evening and keeping only light snacks overnight — could be a practical way to balance comfort with performance and safety.