Exploring circadian and meal timing impacts on cortisol during simulated night shifts

Effects of night eating during simulated shift work on metabolism, cognitive performance, and mood in healthy adults. Australian New Zealand Clinical Trials Registry (ACTRN12616001556437). Statement of Significance This study represents the first investigation into the effects of consecutive simulated night shifts and altered meal timing on cortisol levels. Circadian rhythms are vital for regulating sleep-wake cycles and hormone secretion. Shift work disrupts the natural 24-h light-dark exposure, significantly impacting circadian regulation of behavioral, cellular, metabolic, and physiological processes. Our findings indicate that working night shifts and consuming food during these hours disrupts cortisol rhythms over consecutive nights. This research enhances the understanding of how circadian and behavioral disruptions collectively affect cortisol regulation. Additionally, these insights are crucial for developing effective strategies that address sleep, dietary practices, and eating habits for individuals frequently assigned to night shifts.