Shift Work and Unhealthy Dietary Patterns: Evidence From the Shahedieh Cohort Study

Evidence on the association between shift workers' dietary pattern, particularly in the Middle Eastern populations, remains limited. This study aimed to investigate dietary habits among male shift workers compared to non-shift workers in Iran.

A cross-sectional analysis was conducted using baseline data (2015-2017) of employed male workers enrolled in the Shahedieh cohort study in Yazd, Iran. Dietary intake was assessed using a validated food frequency questionnaire. Shift working status, demographic, socioeconomic, and lifestyle data were collected through structured interviews. Mean daily intake of processed and ultraprocessed food categories was compared between shift workers and non-shift workers. Models were adjusted for covariates. Associations were also analyzed according to the job categories and age.

Among 3,158 participants, 530 (16.8%) were shift workers. Shift workers reported significantly higher intakes of high-fat dairy products (46.3 vs. 39.2 g/day), snacks (1.50 vs. 1.07 g/day), soft drinks (121 vs. 98.2 g/day), and total processed foods (212 vs. 180 g/day) than non-shift workers. Shift workers had lower pizza consumption and different meal frequency patterns compared to non-shift workers. The strong associations observed among driver shift-workers, especially for soft drinks and total processed food intake. Age modified the association of several processed and ultraprocessed food categories.

The findings suggest a less healthy dietary profile in shift workers than in non-shift workers in Iran. These findings highlight the need for targeted nutritional interventions and policies to support healthy eating behavior among shift workers.