The purpose of this study is to determine the effects of dietary modifications on resident physicians' work performance during night shifts.
Specific objectives are:
1. To assess the effects of macronutrient composition of the test meals on cognitive performance, self-reported sleepiness and fatigue of resident physicians during night-time duty.
2. To compare to no intervention, the effects of providing meals before 22:00 hours, and only providing chewing gum, tea, coffee and water onwards to on-call residents, on cognitive performance, self-reported sleepiness and fatigue of resident physicians during night-time duty.