KEY POINTS:
People who sit for extended periods at home and at work are fatter and at greater risk of type 2 diabetes than those who get up and walk around regularly - regardless of whether they exercised daily.
People who rose frequently from breaks at their computer desk or TV couch were found to have a lower blood-glucose level and a 3.2cm smaller waist than the more-committed sitters, the International Diabetes Federation conference in Wellington was told yesterday.
High blood-glucose and large waist circumference can be risk factors for type 2 diabetes and cardiovasculardisease.
Associate Professor David Dunstan, an exercise physiologist at Melbourne's International Diabetes Institute, cited the soon-to-be published research of colleague Dr Genevieve Healy, of Queensland University, during a talk on physical activity and diabetes.
Dr Dunstan said later the findings showed how important it was for people to take regular breaks from their chairs - even if they took a brisk walk every morning. Office workers who drove to work and watched TV to relax in the evenings could spend 15 waking hours each day on their bottoms.
An implication of the study is that some of the rising prevalence of diabetes may be due to the decreasing amount of physical activity people do at work.
But Dr Dunstan said the study was not one which could establish a cause-and-effect relationship and further, more-powerful studies were needed.
But the evidence was growing towards the point where Australia and New Zealand would have to sharpen their official advice on physical activity to include specific recommendations on spending less time sitting.
New Zealand Government health and sport agencies recommend adults do at least 30 minutes of moderate intensity physical activity on most days, plus some vigorous exercise "for extra health benefit and fitness" - advice unchanged since 2001.
But they also recognise the value of incidental activity by advising adults be "active every day in as many ways as possible".
A ministry spokeswoman said the guidelines "will be revised in due course".
Dr Dunstan said, "We've engineered sitting into our work days and engineered physical activity out. It appears that sitting has unique adverse metabolic outcomes."
