Association between occupational psychosocial factors and waist circumference is modified by diet among men

Occupational psychosocial stress has been identified as a risk factor for obesity, whereas dietary habits have a key role in weight control. We examined whether dietary habits modify the association between occupational psychosocial factors and waist circumference.

Data comprised 31-year-old men (n=2222) and women (n=2053) in the Northern Finland Birth Cohort 1966. Waist circumference was measured and data on occupational psychosocial factors (demands, control and social support) and other characteristics were obtained through questionnaires. Healthy and unhealthy diet indices were constructed according to the current dietary guidelines. Associations were examined using analysis of variance adjusted for body mass index at age 14, basic education level, leisure-time physical activity, alcohol consumption, smoking, stress-related eating behaviour and parity.

Among men, high job demands and high job control were associated with greater waist circumferences, and there were interactions between unhealthy diet and job demands (P=0.043) and job control (P=0.036) in relation to waist circumference. The waist of men with high demands or high control and low consumption of unhealthy foods (red/processed meat, hamburgers and pizzas, fried potatoes, sugar-sweetened soft drinks and white bread) was smaller than that of men with high demands or high control and high consumption of such foods. No associations were found among women.

A diet based on the current dietary guidelines seems to cancel out the adverse effects of occupational psychosocial factors on waist circumference among young men. Longitudinal studies are needed to assess the risks for obesity-related diseases arising from psychosocial work environments and dietary habits.