Shiftwork and Nutrition

The biological clock modulates physiological processes in the human body as a
function of time. Human function is defined by activity during day time, and
inactivity during night time. Shift workers, and especially nightshift workers,
are dealing with a mismatch with their biological clock. This results in
increased health (intestinal complaints, overweight, cardiovascular problems,
sleep problems) and safety risks. For example in the nursing profession it is
common to work in shifts. A number of studies reported an association between
fatigue and the prevalence of incidents and medical errors. It has been shown
that meal composition and frequency can enhance shift work related fatigue,
performance and other health related issues such as sleep quality and physical
complaints. However, the number of studies conducted so far, investigating the
role of nutrients on cognition and performance as a function of time-of-day is
limited. Moreover, the quality of research is incomprehensive, because of small
sample sizes and detailed information on macronutrient composition and types of
food is missing. This detailed information is needed in order to set up a
proper intervention study

The primary objective of this study is to investigate the relationship between
diet composition, meal timing, and meal frequency with cognitive performance in
nurses during a night shift setting.
Secondary objectives of this study are 1) to investigate the relationship
between diet composition, meal timing and meal frequency with alertness, day
sleep length and sleep quality, and gastrointestinal complaints in nurses
during a night shift setting, 2) to check whether food consumption and physical
activtiy of nurses who work the night shift meets the dietary guidelines and
the Dutch standard for physical activity and 3) to gain insight in the working
conditions, such as aspects of safety, health, and wellbeing in relation to
food habits of nurses from hospital Gelderse Vallei and hospital Rijnstate.

This observational study will be conducted in nurses who work the night shift.
Nurses are asked to complete 2 general questionnaires at the beginning and end
of the 10 month study period. During the study period, nurses are asked to
complete 5 times a 10-min Psychomotor Vigilance Task, 3 times a 24-recall and a
questionnaire about intestinal complaints, subjective alertness and day sleep.

Participation in the study will not bring any risks. Also patient safety will
not be jeopardized. The burden will be minimized. The only burden is the time
investment. In total it will take about 4 hours distributed over 10 months. In
these 10 months, participants are asked to complete 2 questionnaires at the
beginning and end of the study, 3 times a 24-hour recall after their night
shift and 5 times a 10-min vigilance test during the night shift.
Due to the observational design of the study participants will not receive
short term benefits of the study. Though, at the end of the study participants
receive the results of the Eetscore. These results will give more insight in
the quality of their dietary intake and physical activity.