Long-term control of blood-glucose levels is associated with decreased risk of developing type 2 diabetes and cardiovascular disease.
The trial, done with people of normal weight in Dunedin, builds on the emerging evidence that regular movement is needed for good health in addition to the recommended half hour or more of moderate to vigorous physical activity on most days.
One of the researchers, Dr Meredith Peddie of Otago University, said similar findings were published last year from a trial in overweight and obese people who took a two-minute walk every 20 minutes during five hours of sitting.
"No one else has done the comparison to 30 minutes' continuous physical activity, which a lot of people would expect to be as protective, but we found it was not.
"We were trying to replicate what people would do if they were meeting the current physical activity guidelines by going out for a walk in the morning and then sitting at their desk all day."
Dr Peddie and colleagues wrote in the American Journal of Clinical Nutrition that a simple, non-drug aid that reduced post-meal glucose levels was "paramount to obtaining optimal long-term glycaemic (blood-glucose) control".
Their study indicated sedentary workers would reduce their glucose levels after eating "by regularly getting out of their chair and briskly walking up and down the corridor outside their office". They urged changes be made to the physical and social set-up of offices to provide opportunities for regular breaks from prolonged sitting, such as moving the printer further away and going to talk to people in the same building rather than emailing or phoning them.
They also urged doctors to consider advising patients to regularly break prolonged sitting with brief bouts of activity - as well as doing the currently recommended amount of physical activity.
Heart Foundation medical director Professor Norman Sharpe said a whole new perspective on the disadvantages of being sedentary was emerging. Evidence pointed "to the importance of combating sedentariness and encouraging regular movement".