How Does Shift Work Relate to Nutritional Status, Sleep, and Quality of Life? A Cross-Sectional Study

Abstract

The growing importance of shift work in daily life poses a critical challenge to human biology by disrupting circadian rhythms and adversely affecting metabolic health. Accordingly, in this cross-sectional study, we evaluated the relationships among sleep, nutrition, and quality of life of 512 shift workers (mean age: 32.61 ± 6.70 years) between December 2024 and June 2025. Participants’ self-reported height and body weight were used to calculate their body mass index (BMI), and their sociodemographic characteristics, smoking, and alcohol consumption were assessed. The Bergen Shift Work Sleep Questionnaire was used to assess the insomnia (higher scores indicating worse outcomes), and the Short Form-12 (SF-12), which consists of two subscales (Physical Component Summary-PCS and Mental Component Summary-MCS), was used to evaluate quality of life. Participants were asked to record their 24-h dietary recalls to determine daily energy and nutrient intake. All statistical analyses were conducted in SPSS 27.0, and p-values <0.05 were considered significant. Higher Bergen scores were observed among men, smokers, individuals with lower educational levels, and those working night-morning shifts. The Bergen score showed negative correlations with sleep duration, PCS, MCS, and tryptophan intake, and positive correlations with age, BMI, and caffeine consumption (p<0.05). In multiple linear regression analysis, sleep duration, PCS, MCS, and tryptophan intake were identified as negative predictors of the Bergen score, while age, BMI, and caffeine consumption were identified as positive predictors (p<0.05). In conclusion, this study demonstrates that insomnia and negative sleep parameters, which are common among shift workers, may be related to lifestyle factors, nutritional status, nutritional habits, and quality of life. Notably, night shift workers may be at the highest risk from both metabolic and psychological perspectives. The findings underscore the need for dietary interventions aligned with the circadian rhythm and nutrition counseling strategies to protect sleep health among shift workers.