Long hours and shift work have been associated with cardiometabolic disease risk.
Despite diet being an established modifiable risk factor, few studies have examined how
dietary behaviours vary in relation to working hours. The aim of this thesis was to
investigate the relationship between working hours and diet quality with markers of
cardiometabolic health.
Cross-sectional analyses were conducted using data from The Airwave Health Monitoring
Study - a British police occupational cohort (n=5,849). Number of weekly working hours
was determined from questionnaire data. The Dietary Approaches to Stop Hypertension
score was calculated using 7-day diet data to measure diet quality. Markers of
cardiometabolic health included: adiposity (body mass index, waist circumference and
body fat), blood pressure, cholesterol, HbA1c and C-reactive protein. Sub-group analyses
were conducted in participants with available shift work data (based on police radio
records) (n=2,323). As part of this thesis a revised food diary and shift work questionnaire
were developed and piloted for use in future studies.
Male employees (n=3,332) working >49hrs per week (vs. 35-40hrs) were more likely to
have a dietary pattern associated with elevated cardiometabolic risk. There was a positive
dose-response relationship across working hours (!35-40, 41-48, 49-54, !55hrs per week)
with markers of adiposity in male employees. Diet quality did not modify this association.
Based on limited shift work data: night workers (vs. day) were found to consume a higher
quantity of sugar-sweetened beverages. However shift work was not associated with
increased cardiometabolic risk.
This thesis suggests a sex specific positive association between weekly working hours and
adiposity that is independent of established risk factors. Temporal eating pattern and
previous shift work data collected using the revised food diary and shift questionnaire will
be important to future studies exploring the relationship between diet, work hours and
health.