We always suspected watching too much TV was bad for you, and now it's official....

Australian researchers have established a direct link between diabetes, excessive amounts of television viewing and other forms of physical inactivity.

Findings published by Australian researchers in this month's prestigious American journal Diabetes Care show that diabetes and impaired glucose tolerance (IGT) - a precursor to diabetes - are more common in people who lead sedentary lives and watch more TV.

The research, conducted by the International Diabetes Institute in Melbourne, together with four universities and the Australian Institute of Health and Welfare, contains a very clear message for all Australians. 'Couch potatoes are at twice the risk of developing diabetes than people who spend less time glued to the screen and lead more active lives,' says the Institute's Director, Professor Paul Zimmet.

The findings, based on research involving almost 8,300 Australians who had not previously been diagnosed with diabetes, showed that being active for at least 2.5 hours per week reduced the chances of having IGT or previously undiagnosed diabetes by 38 per cent in men and 29 per cent in women.

IGT and diabetes were increased by 16 per cent in men and 49 per cent in women who watched TV or videos for more than 14 hours per week, compared with those who limited their viewing to seven hours a week or less.

Professor Zimmet said the findings flowed from an Australia-wide study (AusDiab) which the Institute had begun in 1999. This was one of the few studies in the world to give an entire country an accurate 'snapshot' of the health of its population.

AusDiab's initial findings were that:

* Over 7 per cent of adults have diabetes
* 3 in 5 are overweight or obese
* more than half the Australian population has high cholesterol, and
* 50 per cent do not exercise enough.

'Proving the link between diabetes and TV viewing and other forms of sedentary behaviour points the way for those responsible for formulating national health priorities,' Professor Zimmet said.

'These results lend very strong support to recent initiatives by both the Federal and Victorian Governments to get people on the move, especially children. If such campaigns are successful, they should result in a markedly healthier society with declining rates of obesity and diabetes,' he said

The co-chief investigator, Dr Jonathan Shaw said that while too much time in front of the television is now clearly established as a threat to public health, TV sets themselves are not solely to blame.

'The respondents we studied who spent too much time in front of their televisions had also developed bad eating habits. There is little doubt that this contributed to their risk of developing diabetes,' he said.