Caffeine-Containing Food Consumption Throughout A Rotating Shift Schedule

Introduction: Understanding how rotating shifts influence behaviors, such as caffeine intake, is important for optimizing worker performance and well-being. The aim of this study was to assess the variability in caffeine-containing food consumption among shift workers throughout a rotating shift schedule.

Methods: Thirty male shift-workers from a mining company were evaluated in a complete rotation shift cycle over 240 consecutive hours (two days of morning shifts, two days of evening shifts, 24 hours free, two days of night shifts and three days of). Caffeine intake related variables [consumption over a 24-hour period (mg) and consumption during working period (mg)] were assessed by 24 hours recall. Mixed models were used to analyze the fixed effects of shift day on caffeine intake related variables.

Results: The caffeine intake over a 24-hour on N1 (119.7 mg ± 18.6) was higher than all other shift days (p < 0.05), except for E1 (83.0 ± 18.1, p = 0.078). The consumption occurring exclusively during working hours on N1 (62.9 ± 20.0) was also higher compared with the other workdays, except for the second morning shift day (M2 - 25.6 ± 14.7, p = 0.091).

Conclusion: Caffeine consumption appears to be influenced by the shift day, especially during working hours. The night shift seems to promote increased caffeine intake during the night periods for rotating shift workers.

Publikationsverlauf

Artikel online veröffentlicht:
08. Oktober 2025