The stakes of this question extend well beyond the nursing profession itself. Nurses form the largest professional group in the global healthcare workforce, and their wellbeing is tightly linked to patient outcomes, perceived quality of care and organizational performance. A growing body of research has associated night shift work with elevated risks of chronic conditions including type 2 diabetes, metabolic syndrome, cardiovascular disease and certain cancers, along with higher rates of sleep disorders and obesity compared with daytime colleagues. Much of that elevated risk has been attributed to circadian rhythm disruption—the misalignment that occurs when the body’s internal clock is forced to reconcile wakefulness at night with sleep during daylight hours. Because meal timing, digestion and metabolism are all governed by circadian regulation, understanding precisely how shift schedules reshape eating behaviour has become a central question in occupational health research.

Previous studies have generally painted a consistent picture: night shift workers tend to consume more total energy, favour energy-dense foods and sugar-sweetened beverages, snack more frequently, and eat more carbohydrates and saturated fats than their day-working peers. Reviews have described night nurses skipping breakfast and lunch, eating dinner late, and grazing on high-fat, sugar-rich snacks during overnight shifts. Meal skipping itself has been linked to metabolic dysfunction, and the American Heart Association has issued a scientific statement emphasizing that meal timing and frequency matter for cardiovascular disease prevention. Yet the evidence has not been unanimous. Some studies have failed to confirm the link between night work and overweight or obesity, and much of the existing data rely on self-reported dietary information, which researchers urge should be interpreted cautiously.

To probe these questions, the Italian research team recruited 408 nurses through dedicated nursing communities on Facebook and Instagram, using a Google Forms questionnaire. Participants reported their sex, age, years of professional experience, educational level, smoking habits, height and weight, and the nature of their shift work—whether they worked only between 8 a.m. and 8 p.m. or also covered the night window from 8 p.m. to 8 a.m. The survey also asked about the number of meals consumed per day, whether snacks were eaten between main meals, and whether meals were taken at regular times, with reference to Italian dietary recommendations. Body mass index was calculated and classified into standard categories ranging from underweight to obese.

The study’s most distinctive feature, however, was its use of the Eating Disorder Flexibility Index, or EDFLIX, a 36-item questionnaire measuring cognitive and behavioural flexibility around food, exercise, weight and body shape. Higher scores indicate a greater capacity to adapt eating-related attitudes and behaviours flexibly rather than rigidly—a trait previously associated with healthier responses to food intake, whereas inflexibility has been linked to disordered eating patterns. Because no validated Italian version existed, the researchers translated the instrument and asked 30 nurses to rate the clarity and relevance of every item on a structured validation checklist; all rated the items strongly agreeable, and the translated questionnaire showed good internal consistency, with a Cronbach’s alpha of 0.752 for the total score in the main sample.

The results defied several expectations. Of the 408 participants, 109 nurses (26.7 percent) worked exclusively daytime shifts while 299 (73.3 percent) also worked nights. The two groups differed significantly in work characteristics: night shift nurses were markedly younger in professional experience, with 27.9 percent reporting fewer than five years of employment compared with 8.1 percent of daytime-only nurses, and they were more likely to hold full-time positions. Yet when the researchers turned to eating patterns, the anticipated differences largely failed to materialize. The number of meals consumed per day did not differ significantly between groups, nor did the regularity of meal timing, though the latter came close to the significance threshold. Body mass index categories and smoking habits were also statistically indistinguishable between the two shift groups.

The single significant difference concerned snacking between main meals, and it ran in the opposite direction from much of the prior literature. Fully 83 percent of daytime-only nurses reported eating snacks between their principal meals, compared with 68 percent of nurses who worked night shifts—a difference the authors deemed statistically significant. This finding directly contradicts evidence from Lebanese nurses, where night shift work was associated with less healthy eating, irregular meal timing and greater consumption of high-fat, sugar-rich snacks during overnight hours. It also sits awkwardly with the physiological model that has dominated the field, in which circadian disruption alters appetite-regulating hormones—suppressing leptin, the satiety signal, and elevating ghrelin, the hunger signal—thereby driving increased snacking and meal skipping among night workers.

Equally striking was the absence of any difference in eating behaviour flexibility. Analyses of the EDFLIX total score and its three sub-dimensions—general flexibility, food and exercise flexibility, and weight and shape flexibility—revealed no statistically significant differences between daytime and night shift nurses. The authors suggest this indicates that flexibility in eating, exercise and body-shape-related behaviours is independent of nursing shift work, a conclusion at odds with earlier reports of reduced physical activity among night shift nurses due to fatigue. The lack of association between night work and body mass index in this sample echoes some previous studies that failed to confirm the shift work–obesity link, even as systematic reviews and meta-analyses have generally supported it, pointing to weight gain and increased waist circumference likely driven by excess caloric intake during night work.

The researchers are candid about the limitations that temper these conclusions. Recruitment through social media introduced substantial selection bias and limits generalizability, and the two comparison groups were markedly unbalanced in size. The night shift group was not subdivided into fixed and rotating schedules, even though schedule predictability could plausibly influence eating behaviour. The questionnaire captured only a limited set of dietary variables, online self-report may have affected data quality, and the cross-sectional design means no causal inferences can be drawn about the relationship between shift work, diet, body weight or physical activity. Non-significant findings, the authors caution, should be interpreted with appropriate care.

Even so, the study offers a useful corrective to a field prone to simple narratives, and the authors frame it as a preliminary contribution to a complex and multifaceted topic. Night shift nurses do appear to experience alterations in their relationship with food and physical activity, but the key underlying factors remain highly controversial. The team plans to examine the nutritional composition of snacks and explore meal patterns in greater depth, moving beyond simple counts of meals per day. In the meantime, they argue that targeted health promotion strategies to foster healthy eating behaviours among nurses—regardless of shift—could be essential to protect a workforce whose health underpins the performance of entire healthcare systems, and to prevent the long-term adverse outcomes that decades of shift work research have made all too familiar.

Subject of Research: The impact of day versus night shift work on eating behaviours, snacking patterns and eating flexibility among nurses

Article Title: How Shift Work Impacts on Eating Behaviours Among Nurses: A Cross‐Sectional Study

Article References: Chang, Y.-C., Mea, R., & Vitale, E. (2026). How Shift Work Impacts on Eating Behaviours Among Nurses: A Cross‐Sectional Study. Nursing Open, 13(10), Article e70884. https://doi.org/10.1002/nop2.70884

Image Credits: AI Generated

DOI: 10.1002/nop2.70884

Keywords: shift work, nurses, eating behaviours, snacking, circadian rhythm, body mass index, EDFLIX, occupational health, cross-sectional study, meal patterns, metabolism, healthcare workforce

Recent insights from a comprehensive scientific statement published by the American Heart Association underscore the critical relationship between circadian health and the spectrum of cardiometabolic diseases, including obesity, Type 2 diabetes, hypertension, and cardiovascular disease itself. This statement elucidates how the misalignment of circadian rhythms—frequently induced by modern lifestyle factors—catalyzes disruptions in metabolic regulation and hormonal balance, accelerating disease progression and increasing mortality risk.

At the cellular core of circadian regulation lie networks of clock genes such as CLOCK, BMAL1, PER, and CRY, which generate rhythmic patterns of gene expression that tune physiological activities to external environmental cues. Central to this system is the suprachiasmatic nucleus (SCN) in the brain’s hypothalamus, which synchronizes bodily functions primarily through light signals perceived by retinal photoreceptors. This elegant synchronization ensures that bodily processes peak at optimal times aligned with the natural day-night cycle, fostering metabolic efficiency and cardiovascular homeostasis.

Yet, when behavioral patterns such as sleep timing, meal consumption, and physical activity fall out of sync with this internal clock, circadian disruption ensues. For example, individuals forced to awake during their biological night—common in shift workers or travelers experiencing jet lag—experience a misalignment that amplifies cardiometabolic risk. This phenomenon illustrates that lifestyle-induced perturbations extend beyond mere inconvenience, imposing biological stresses that compromise health.

The statement emphasizes that not only the duration of sleep but its timing consistency is paramount. Irregular sleep patterns—often seen as “social jet lag”—where sleep schedules differ drastically between workdays and free days, disrupt circadian synchrony and elevate risks for obesity and impaired glucose metabolism. Emerging evidence links variability in sleep timing and duration to dysregulated glycemic control, highlighting the intricate connection between circadian rhythm fidelity and diabetes risk.

Equally influential is the timing of light exposure, which acts as the dominant zeitgeber—or time cue—for the circadian clock. Morning exposure to natural light fosters phase advancement, promoting earlier sleep onset and metabolic stability. Conversely, exposure to artificial light, especially blue spectra emitted by electronic screens during the night, suppresses melatonin production, delays sleep, and has been associated independently with heightened cardiovascular risk. Even low-intensity nocturnal light can provoke deleterious effects, suggesting the pervasive impact of light pollution on public health.

Moreover, the timing of meals wields metabolic influence far beyond caloric content alone. Late-night eating or irregular meal patterns disrupt peripheral clocks localized within key metabolic organs, such as the liver and pancreas. These disruptions impair glucose homeostasis and lipid metabolism, predisposing individuals to weight gain and elevated cardiometabolic risk. Notably, consuming breakfast before 8:00 a.m. correlates with more favorable glycemic profiles and reduced incidence of Type 2 diabetes, signifying the metabolic benefits of time-restricted feeding aligned to circadian phases.

Physical activity also interacts with circadian physiology as a potent secondary synchronizer. Exercise timing modulates circadian phase shifts: morning or afternoon workouts generally induce phase advancements, whereas late-evening exercise may delay circadian rhythms. These timing-dependent effects influence outcomes ranging from blood pressure regulation to glucose control and sleep quality. However, deeper mechanistic understanding and personalized timing protocols warrant further rigorous investigation to refine recommendations.

Circadian misalignment is notoriously exacerbated in populations subjected to irregular schedules and environmental stressors. Shift workers endure compounded risks due to inconsistent sleep, erratic mealtimes, and continuous exposure to artificial light during night shifts. This disruption manifests as a well-documented risk factor for cardiovascular disease and metabolic derangements, underscoring the critical need for occupational health strategies that mitigate circadian disturbance.

Importantly, individuals vary markedly in their intrinsic circadian timing—referred to as chronotype—ranging from early “larks” to late “owls.” This biological diversity influences responsiveness to timed light exposure, feeding, and exercise interventions. Tailoring behavioral and therapeutic strategies to an individual’s natural internal clock holds promise for maximizing circadian alignment and enhancing cardiometabolic outcomes. Yet, effective assessment tools remain limited largely to controlled laboratory environments.

Advancements in wearable digital technology, alongside emerging biomarkers and artificial intelligence analytics, portend transformative capabilities to noninvasively map circadian rhythms in real-world settings. Continuous monitoring of physiological indicators such as heart rate variability, skin temperature, and activity cycles could enable personalized circadian profiling, empowering clinicians and individuals to optimize lifestyle interventions in alignment with their unique biological timing.

In practical terms, simple behavioral modifications grounded in circadian principles may yield substantial cardiovascular and metabolic benefits. Consistently timed sleep and wake schedules, earlier meal consumption, and prioritizing morning sunlight exposure constitute foundational strategies to reinforce the body’s natural rhythm. While the American Heart Association advocates these principles grounded in current evidence, ongoing research remains crucial to establish causality and refine individualized, evidence-based timing recommendations.

This scientific statement reflects a collaborative effort by multidisciplinary experts in sleep, neurology, cardiology, and metabolic health, signaling a pivotal shift toward integrating chronobiology into mainstream cardiovascular disease prevention and management frameworks. As science elucidates the mechanistic underpinnings linking circadian dysregulation to cardiometabolic pathology, the imperative emerges to embed circadian health within public health policies and clinical protocols.

In an era where 24/7 connectivity and around-the-clock societal demands imperil the synchrony of our internal clocks, the message is clear: honoring the innate rhythms of our biology is fundamental to safeguarding metabolic and heart health. Listening to and aligning with our circadian timing may unlock new avenues for disease prevention, improve quality of life, and ultimately extend longevity.

Subject of Research: Circadian health and its role in cardiometabolic disease risk, including obesity, Type 2 diabetes, cardiovascular disease, and the impact of lifestyle factors on circadian rhythm alignment.

Article Title: Role of Circadian Health in Cardiometabolic Health and Disease Risk: A Scientific Statement From the American Heart Association

News Publication Date: October 28, 2025

Web References:

• AHA Scientific Statement – Circulation
• American Heart Association – Life’s Essential 8
• Cardiovascular Disease Overview
• Obesity and Cardiometabolic Health
• Type 2 Diabetes Information
• High Blood Pressure Resources
• Cardiovascular-Kidney-Metabolic Health Initiative

References: Detailed author disclosures and full citation available in the original publication.

Keywords: Circadian rhythms, cardiometabolic health, obesity, Type 2 diabetes, hypertension, cardiovascular disease, chronotype, metabolic regulation, sleep timing, light exposure, meal timing, shift work