Indeed, if you watch more than two hours of television a day, you are more likely to smoke, be overweight, have poor cardio-respiratory fitness and high cholesterol. You are more likely to leave school without qualifications, and less likely to attain a university degree.

Those are the conclusions from the first-ever long-term study on the effects of television, conducted at Otago’s Multidisciplinary Research Unit.

“Other studies have hinted at the same sort of associations,” says the unit’s deputy director Dr Bob Hancox. “But this is the first time the consequences of television viewing have been tracked over people’s lives.”

The studies, carried out by Hancox along with MDRU colleagues Associate Professor Richie Poulton and Barry Milne, have now been published in the international journals Archives of Pediatric and Adolescent Medicine, International Journal of Obesity and The Lancet.

The team, originally led by Dr Phil Silva, followed 1,037 people born in Dunedin in 1972-73. Every two years between the ages of five and 15, they were asked how much television they watched. These results were compared with the participants’ health and education status at the age of 26.

Children and television An interesting finding was that adolescent viewing was strongly associated with leaving school without qualifications, whereas early-childhood viewing was a stronger predictor of non-attainment of a university degree.

And the studies detail some even more chilling news for viewers and their parents. The results indicate the same conclusions even once they have been corrected for people’s intelligence, socio-economic status, sex and early behavioural problems.

While the research unit’s findings point to associations, the questions of why these associations occur are not always easy to answer.

“It might be that the instant gratification children expect from watching television does not encourage the kind of effort that’s needed to achieve a tertiary qualification,” Hancox speculates.

Similarly, Hancox believes the relationship between one’s health and TV watching may be more complicated than simply the sedentary nature of “vegging out” on the sofa. “Television viewers are exposed to an onslaught of advertisements for junk food and images of people smoking.” And with most television characters being slim and healthy-looking, the damaging health effects are underplayed in people’s minds, suggests Hancox.

But whatever the reasons behind the findings, Hancox bridles when his research is used as an opportunity to berate parents for “using the TV as a babysitter”.

“Parents are busy. They cannot supervise their children all the time. And parents don’t exist in a vacuum – society decides what ads are played on TV, what is expected of parents and what resources parents have.

“If, as a community, we decide we want there to be better alternatives to watching television after school, then we need to provide them.”

Even though the study’s participants were doing their TV watching in the late 1970s, Hancox thinks the findings can be applied today.

“If anything, they will probably be amplified,” he says. “Broadcasting hours are longer, there are more channels to choose from, advertising minutes have increased and many homes have more than one TV. And we don’t seem to be seeing any dramatic improvement in the quality of programming – we’ve pretty much just swapped the Flintstones for Spongebob.”

Does this mean we are raising a generation of unhealthy dullards? Hancox won’t go that far. “You don’t need a tertiary education to lead a fulfi lling life or make a good contribution to society.

“But it does seem that television is preventing some people from fulfilling their academic potential.”