Associations between Shift Work and Empty Calorie Food/Beverage Consumption

Background Shift work may be a barrier to healthy eating behaviors among workers. However, the evidence is mainly built on comparisons of eating behaviors between shift workers and non-shift workers. Under what conditions shift work increases the likelihood of unhealthy eating behaviors is still unknown. Growing research also suggests daily experiences and exposures may contribute to fluctuations in people’s daily eating behaviors. Purpose Addressing the research gaps, the goals of this dissertation were to examine the within-person associations between shift work and empty calorie food/beverage consumption and to test whether these associations were exacerbated by daily poor sleep quality or shorter sleep duration. Methods This was a 14-day intensive longitudinal study using ecological momentary assessment. A convenience sample of 80 hospital registered nurses in Taiwan participated. A 21-item food checklist assessed participants’ empty food/beverage consumption. Three dimensions of shift work (i.e., shift timing, shift intensity, and shift speed) were derived from the registry-based work schedule. Daily sleep quality and duration were assessed with the Core Consensus Sleep Diary and Actigraph GT3X, respectively. Three-level mixed-effects regression models were employed for hypothesis testing. Results Participants on night shifts compared to day shifts had greater empty calorie food/beverage consumption. Greater night shift intensity was positively associated with the increased likelihood of sweetened beverage intake. Higher levels of shift speed exacerbated positive associations between (a) shift timing and (b) work shift intensity with sweetened beverage consumption. On days with poor sleep quality, the association between working night shift and fried food/fast food intake was stronger. Relative to slow shift speed workers, poor sleep quality was positively associated with medium/rapid shift speed workers’ likelihood of fried food/fast food consumption. Conclusions Night shift work is associated with increased empty calorie food/beverage consumption among workers. Poor sleep quality exacerbated the adverse effects of shift work on fried food/fast food consumption. Therefore, strategies to promote less hazardous shift work assignments and improve shift workers’ sleep hygiene may help to reduce their empty calorie food/beverage consumption and ultimately their health.