Dietary intake and dinner timing among shift workers in Japan

Association of breakfast skipping with habitual dietary intake and BMI in female rotating shift workers

OBJECTIVE

Higher BMI, lower quality of diet and a higher percentage of breakfast-skippers have been reported among rotating shift (RS) workers compared with day shift (DS) workers. As such, this study examined the association between breakfast skipping, habitual food consumption and BMI in RS workers.

DESIGN

Japanese nurses were studied using a self-administered questionnaire that assessed the height, weight, breakfast consumption habits, dietary consumption, physical activity, sleep habits, chronotype and demographic characteristics of the participants.

SETTING

A cross-sectional study was conducted in a population of nurses in Japan. Dietary and health-related questionnaires were mailed to 5536 nurses aged 20-59 years, working at 346 institutions.

PARTICIPANTS

A total of 3646 nurses at 274 institutions responded to the questionnaire. After removing those who met the exclusion criteria, 2450 participants were included in the statistical analysis.

RESULTS

The RS breakfast-skippers had lower total energy intake, diet quality and higher BMI than DS workers, whereas the RS breakfast-consumers had a higher total energy intake and BMI than the DS workers. In the RS workers, breakfast skipping on the days of DS and the end days of evening/night shift was associated with a poorer diet quality. Additionally, breakfast skipping on the days of DS was positively associated with BMI, independent of the total energy intake and diet quality.

CONCLUSIONS

Breakfast skipping on workdays may contribute to a difference in dietary intake and BMI between RS workers and DS workers and may increase BMI in RS workers, independent of dietary intake.

Overweight/obesity and physiological variables in workers exposed to rotating shift in a food production factory

Introduction

Shift work has been hypothesized as a potential risk factor for overweight/obesity or other metabolic changes. We examined the relationship between work shift and body mass index, waist-hip ratio, lipid profile, and glucose concentration in workers from a food manufacturing factory in Colombia.

Objectives

To investigate the association between shift work and changes in physiological variables in food manufacturing industry workers in Medellín, Colombia.

Methods

This cross-sectional study was conducted with 763 employees from a food manufacturing factory. Information was collected from the medical records from the occupational health provider institution in charge of workers' periodic follow-up.

Results

The study sample consisted of 637 (83.5%) men and 126 (16.5%) women. Mean age was 43.35 ± 9.8 years, and mean body mass index was 25.49 ± 3.23 kg/m2. After adjusting for potential confounders, logistic multivariate regression revealed a statistically significant association between shift work and higher body mass index and higher total cholesterol levels compared with dayshift (p < 0.05). Finally, the analysis of waist-hip ratio for each shift scheme and sex showed that this ratio was higher for rotating shift workers, with a significant difference for women.

Conclusions

Significant associations were observed between shift work and overweight/obesity and hypercholesterolemia. However, these findings should be confirmed by longitudinal studies.

The impact of circadian timing on energy balance: an extension of the energy balance model

A significant proportion of the population is classified as having overweight or obesity. One framework which has attempted to explain biobehavioral mechanisms influencing the development of overweight and obesity is the energy balance model. According to this model, the body continually attempts to balance energy intake with energy expenditure. When energy intake and energy expenditure become imbalanced, there is an increase in homeostatic and allostatic pressure, generally to either increase energy intake or decrease energy expenditure, so as to restore energy homeostasis.Recent research has indicated that circadian aspects of energy intake and energy expenditure may influence energy balance. This paper provides a narrative review of existing evidence of the role of circadian timing on components of energy balance. Research on the timing of food intake, physical activity, and sleep indicates that unhealthy timing is likely to increase risk of weight gain. Public health guidelines focus on how much individuals eat and sleep, what foods are consumed, and the type and frequency of exercise, but the field of circadian science has begun to demonstrate that when these behaviors occur may also influence overweight and obesity prevention and treatment efforts.

Adherence to dietary and physical activity guidelines among shift workers: associations with individual and work-related factors

Objectives

Shift work is associated with adverse effects on the health and lifestyle behaviours of employees. This study aimed to examine factors associated with adherence among shift workers to selected indicators of dietary and physical activity guidelines.

Methods

A cross-sectional study was conducted on 1300 shift workers. Data were collected using a 15 minute telephone-administered questionnaire. Logistic regression methods were used for data analysis.

Results

Male shift workers (p<0.001, OR=0.55, 95% CI 0.40 to 0.74) and those of lower socioeconomic status (p=0.046, OR=0.75, 95% CI 0.57 to 0.99) were significantly less likely to consume five or more daily servings of fruits and vegetables. Shift workers with access to workplace vending machines were significantly more likely to consume soft drinks at least weekly (p=0.003, OR=1.64, 95% CI 1.18 to 2.27). Middle-aged shift workers (p=0.012, OR=0.65, 95% CI 0.46 to 0.91) and those reporting insufficient break times at work (p=0.026, OR=0.69, 95% CI 0.49 to 0.96) were significantly less likely to be sufficiently active.

Conclusions

Individual, work schedule and workplace environment related factors were independently associated with selected indicators of adherence to dietary and physical activity guidelines in this cohort of shift workers.

Impact of Shift Work on the Eating Pattern, Physical Activity and Daytime Sleepiness Among Chilean Healthcare Workers

We evaluated the eating pattern, physical activity, and daytime sleepiness level in Chilean shift workers. Fifty, middle-aged adult health workers from a public hospital in Santiago, Chile, were included: a group undergoing shift work (shift workers, including at least one “night shift” and one “long day”, n = 33), and day workers under traditional schedule (from 8:00 to 17:00h, n = 17). Body composition, physical activity, and daytime sleepiness levels, and diet characteristics (diet composition, meals' timing, and diet quality) were assessed. Despite similar total energy intake, shift worker showed lower carbohydrate (% of energy) and higher protein intake (both P < 0.01), decreased diet quality, an irregular eating pattern, and delayed meal timing (all P < 0.05). Physical activity and daytime sleepiness levels did not differ between groups. Findings from this first Chilean study in healthcare shift workers support the fact that meal timing and diet quality appear as critical factors for upcoming intervention studies in this group.

Association between Dietary Intake and Autistic Traits in Japanese Working Adults: Findings from the Eating Habit and Well-Being Study

“Autistic traits” include a wide range of severity levels. They are often subclinical, and widely distributed in the general population. It is possible that food selectivity due to hyper- or hypo-reactivity to smell or texture, an autistic feature, may result in inadequate nutrient intakes even among non-clinical adults with autistic traits. However, dietary intake of adults with autistic traits has not been elucidated. This study aimed to investigate an association between dietary intake and autistic traits. We cross-sectionally analyzed data of 1440 men and 613 women extracted from the Eating Habit and Well-Being study. Autistic traits were assessed using the Japanese version of the Subthreshold Autism Trait Questionnaire (SATQ), and dietary intake was assessed using a validated food frequency questionnaire. Iron and vitamin B₁₂ intakes were marginally and inversely associated with the SATQ score in men. The SATQ score in women was positively associated with carbohydrate intake, but had an inverse association with protein, mineral, vitamin, and dietary fiber intakes. Low intakes of seaweed, fish and shellfish, and vegetables were observed in participants with severe autistic traits. Associations of autistic traits with food selectivity and low nutrient intakes should be further investigated to promote a new dietary strategy in the general population.

Low Zinc, Copper, and Manganese Intake is Associated with Depression and Anxiety Symptoms in the Japanese Working Population: Findings from the Eating Habit and Well-Being Study

Epidemiological studies have suggested that there is an association between diet and mental health. The aim of this study was to investigate the association between the intake of six minerals and mental disorders in a cross-sectional study. We used data from the Eating Habit and Well-being study in Japanese workers. Kessler’s six-item psychological distress scale was used to detect mental disorders, with a cut-off score of 12/13, and a validated food frequency questionnaire was used to estimate dietary mineral intake. A total of 2089 participants with no history of depression were included. The prevalence of mental disorders was 6.9%. The lowest quartiles of zinc, copper, and manganese intakes were associated with mental disorders, whereas the lowest quartiles of calcium, magnesium, and iron intake were not associated with mental disorders. Combination analysis of high (≥median) or low (<median) intake of zinc, copper, and manganese showed that low zinc and low copper intake, even with low or high manganese intake (odds ratio (OR), 2.71, 95% confidence interval (CI), 1.29–5.73, and OR, 3.06, 95% CI, 1.41–6.61, respectively) showed a higher OR than that of high zinc, high copper, and high manganese intake. Further studies are required to investigate the impact of dietary mineral intake on mental health.