Lifestyle Interventions to Improve Health in Female Shift Workers

Abstract

Night shift work disrupts circadian rhythms and is strongly associated with increased risks of metabolic and mental health disorders, including obesity, diabetes, cardiovascular disease, and depression. This dissertation explores these health consequences and investigates targeted interventions aimed at mitigating them. Chapter 1 provides a comprehensive review of circadian misalignment and its physiological effects linking shift work to adverse metabolic outcomes. Chapter 2 presents a systematic review of 23 clinical trials examining dietary interventions in night shift workers. Findings reveal that altering meal timing, improving diet quality, and overnight fasting significantly improved glycemic control, anthropometric markers, and cardiovascular health. Chapter 3 details a randomized controlled crossover trial evaluating the effects of an 8-week lifestyle intervention focused on increased protein intake, reduced overnight carbohydrate consumption, and improved sleep in female healthcare night shift workers. While trends toward improved physical and mental health were observed, no statistically significant changes were noted in visceral fat or inflammatory markers likely due to small sample size and short duration. Chapter 4 investigates the impact of this same intervention on gut microbiome diversity. Although alpha diversity measures remained unchanged, beta diversity showed that they were compositionally different across all time points. This work underscores the complex relationship between circadian disruption and metabolic health, advocating for multifaceted, individualized strategies encompassing diet, sleep, and microbiome modulation to improve health outcomes in night shift workers. Further longitudinal research with larger cohorts is warranted to validate these findings and develop practical interventions.