Melbourne: Your job could be having an effect on your waistline, suggests a new study which found work that requires you to make a lot of decisions is linked to bigger waist size.
The study, by researchers at the University of Adelaide, Central Queensland University and the University of South Australia, shows that having skills and the freedom to use them at work is linked to lower body mass index (BMI) and smaller waist size, whereas needing to make a lot of decisions is linked to bigger waist size.
The findings suggest for the first time that these two psychological measures of control at work may actually have very different effects on our waistlines, so should be assessed separately.
Control in your job can come in two broad forms: skill discretion - having and being able to apply skills - and decision authority.
Traditionally, increasing an employee's level of job control has been seen as a good thing and the two factors have been considered together when looking at their effect on people's health.
However, the new study suggests that the two aspects of job control should be considered separately in terms of their effects on health, and obesity in particular.
"Many people point to 'eating too much and not moving enough' as the cause of obesity," said lead author Christopher Bean, a health psychology PhD candidate from the University of Adelaide.
"While this might explain how weight gain often happens, it does not acknowledge things such as environmental, psychological, social or cultural factors," said Bean.
For the study, Bean and colleagues looked at a sub-set of data from 450 mostly middle-aged participants (230 women, 220 men), who worked in a variety of different occupations, both blue and white-collar.
They measured participants' height, weight and waist circumference in a clinic and conducted telephone interviews to collect information about their work.
They used a model called the Job Demand-Control-Support (JDCS) model to assess the psychosocial qualities of their work.
Traditionally, high job demands are considered stressful, while high job control has been considered useful in mitigating the effects of high demands.
However, skill discretion and decision authority are usually assessed together.
In the new study, the team took these two factors separately. After controlling for sex, age, household income, work hours and job nature, these two factors were comparatively strongly associated with obesity, with surprisingly opposite effects.
The study was published in the journal Social Science & Medicine.