Objective: Higher body mass index (BMI) values have been reported in rotating shift workers compared with regular daytime workers. This study examines the relationship between work schedule and BMI, and considers whether lifestyle habits could explain the relationship. Methods: Japanese female nurses (1179 day workers and 1579 rotating shift workers, aged 20-59) were studied using self-administered questionnaires. The questionnaires assessed height, weight, and dietary intake, physical activity, and sleep (lifestyle) habits. Results: The BMI of shift workers was significantly higher than that of day workers. Shift workers consumed significantly higher amounts of sugar-sweetened beverages and slept for significantly shorter durations on nights between days on the day shift compared with day workers-factors which were also independently associated with higher BMI. In addition, multivariable linear regression coefficients for BMI showed a significant correlation with rotating shift work (b 5 0.051), after controlling for lifestyle habits. Conclusions: Higher consumption of sugar-sweetened beverages and shorter sleep duration were associated with rotating shift work and higher BMI. This should be taken into consideration in preventing obesity in real-life shift work situations. Other shift work-related factors, such as abnormal timing of meals and/or sleep, should also be identified.

BackgroundFood frequency questionnaires (FFQs) have been developed and validated for various populations. To our knowledge, however, no FFQ has been validated for young athletes. Here, we investigated whether an FFQ that was developed and validated to estimate dietary intake in middle-aged persons was also valid for estimating that in young athletes.MethodsWe applied an FFQ that had been developed for the Japan Public Health Center-based Prospective Cohort Study with modification to the duration of recollection. A total of 156 participants (92 males) completed the FFQ and a 3-day non-consecutive 24-hour dietary recall (24hDR). Validity of the mean estimates was evaluated by calculating the percentage differences between the 24hDR and FFQ. Ranking estimation was validated using Spearman’s correlation coefficient (CC), and the degree of miscategorization was determined by joint classification.ResultsThe FFQ underestimated energy intake by approximately 10% for both males and females. For 35 nutrients, the median (range) deattenuated CC was 0.30 (0.10 to 0.57) for males and 0.32 (−0.08 to 0.62) for females. For 19 food groups, the median (range) deattenuated CC was 0.32 (0.17 to 0.72) for males and 0.34 (−0.11 to 0.58) for females. For both nutrient and food group intakes, cross-classification analysis indicated extreme miscategorization rates of 3% to 5%.ConclusionsAn FFQ developed and validated for middle-aged persons had comparable validity among young athletes. This FFQ might be useful for assessing habitual dietary intake in collegiate athletes, especially for calcium, vitamin C, vegetables, fruits, and milk and dairy products.

ObjectivesOur study examines differences in eating behaviour between day workers and rotating shift workers, and considers whether diurnal preference could explain the differences.MethodsJapanese female nurses were studied (39 day workers and 123 rotating shift workers, aged 21–63 years) using self-administered questionnaires. The questionnaires assessed eating behaviours, diurnal preference and demographic characteristics. The questionnaire in the Guidelines for the management of obesity disease issued by the Japan Society for the Study of Obesity was used to obtain scores for the levels of obesity-related eating behaviours, including cognition of constitution, motivation for eating, eating as a diversion, feeling of satiety, eating style, meal contents and temporal eating patterns. The Japanese version of the Morningness–Eveningness (ME) questionnaire was used to measure self-rated preference for the degree to which people prefer to be active in the morning or the evening (ME).ResultsThe scores for meal contents and temporal eating patterns in rotating shift workers were significantly higher than those in day workers. The ME score of rotating shift workers was significantly lower, indicating greater eveningness/less morningness among rotating shift workers. Multivariate linear regression revealed that the ME score was significantly negatively associated with temporal eating patterns and showed a negative association with the score for meal contents at a trend level, while current work shift was not significantly correlated with the scores.ConclusionsThese results suggest that eating behaviours for rotating shift workers are associated with a more unbalanced diet and abnormal temporal eating patterns and that the associations may be explained by diurnal preference rather than by rotating shift work.

Timing of meals was a key factor in regulating circadian phases of the cardiac autonomic nervous system and lipid metabolism.