Associations of perceived work stress and work schedule with dietary habits

Katri Hemiö

Research output: ThesisDoctoral ThesisCollection of Articles


Work conditions can have a substantial impact on workers’ lifestyles and thus, on the development of chronic diseases. One important determinant of the risk of chronic disease is diet. The aim of this thesis was to examine the role that perceived work stress and work schedule may play in workers’ dietary habits in a shift-work intensive workplace. In order to facilitate reliable evaluation of workers’ dietary habits, a brief food intake questionnaire (FIQ) was also validated. This thesis is based on data from a screening and prevention programme for chronic diseases implemented in a Finnish airline company between 2006 and 2008. The programme consisted of a health assessment of the participants and a discussion on the health assessment results with an occupational health physician or nurse. The assessment involved measurements of height, weight, waist circumference and blood pressure; blood tests; comprehensive questionnaires covering work, work schedule, sleep, perceived stress, stress symptoms, diseases, medication, lifestyle habits; the type 2 diabetes risk score FINDRISC; and a fasting glucose measurement. An FIQ was filled in by the participants whose risk of type 2 diabetes was elevated and by the participants who took part in the FIQ validation study. The follow-up study was carried out in 2009 to 2010. The health assessment was similar to that at baseline except that the study questionnaire was extended to include the FIQ and more detailed work-related questions. Cross-sectional data were used for the FIQ validation study (n=77); the shift schedules and dietary habits study (n=1478); and the recovery from work, sleep and dietary habits study (n=1342). The effect of work stress changes on dietary habits was evaluated in a prospective design, with a 2.4-year follow-up (n=366). The relative validity of the FIQ, using a seven-day food diary as a reference method, was shown to be acceptable for estimating participants’ food intake. Based on the FIQ answers, nutrient intake models were created separately for men and women; for proportions of energy from fat, saturated fat and sucrose; as well as for amount of fibre, vitamin C, iron, and vitamin D. These models were used to calculate the estimated nutrient intakes of the workers in the study cohort. The dietary habits of the work schedule groups differed and were better among the day workers. Male shift workers’ fruit and vegetable consumption was lower than that of male day and in-flight workers. Older age was associated with higher vegetable and fruit consumption among both men and women. The quality of fat in the day workers’ diets was better than that in the shift or in-flight workers’ diets. Poor recovery from work and sleep problems were associated with many unhealthy dietary habits, including more eating occasions, higher fast food and sweet consumption, and lower fruit and vegetable consumption among men; and more eating occasions, higher fast food, desserts, and sweet consumption among women. During over two years of follow-up, an increase in stress and decrease in work ability were associated with an increase in fat and saturated fat intake among men, as well as an increase in night shifts was associated with increased fat and saturated fat intake among women. In conclusion, shift schedule, higher perceived stress, poor recovery from work, sleep problems, and reduced work ability were associated with worse dietary habits, especially among men. The effects were seen as reduced consumption of fruit and vegetables as well as a higher fat and saturated fat intake. Shift workers’ risk of coronary heart diseases has already been proven, and this effect may be partly mediated by poor diet. The increase in saturated fat in parallel with increased work stress observed in this study may increase this risk among shift workers. Therefore, occupational health services should incorporate diet quality assessment into routine health examinations, together with dietary counselling targeted especially towards workers with high levels of stress.
Original languageEnglish
  • Lindström, Jaana, Supervisor, External person
  • Puttonen, Sampsa, Supervisor, External person
Place of PublicationHelsinki
Print ISBNs978-951-51-6068-3
Electronic ISBNs978-951-51-6069-0
Publication statusPublished - 2020
MoE publication typeG5 Doctoral dissertation (article)

Bibliographical note

M1 - 87 s. + liitteet

Fields of Science

  • Aviation
  • Diabetes Mellitus, Type 2
  • Dietary Fats
  • Eating
  • Feeding Behavior
  • Food
  • Fruit
  • Occupational Health
  • Physical Examination
  • Risk Factors
  • Shift Work Schedule
  • Sleep
  • Sleep Wake Disorders
  • Vegetables
  • Work
  • 3142 Public health care science, environmental and occupational health
  • 3121 Internal medicine

Cite this