Limit TV watching to 2 hours to live longer, say scientists
It is now well known that spending too much time sitting down is bad for the heart, even if one takes regular exercise.
Now American scientists have tried to quantify exactly how risky it is to spend too long on the sofa.
By looking at a number of separate studies and pooling the results, they estimated that if people limited their television viewing to a maximum of two hours a day, from birth, they would live on average 1.4 years longer than they do now.
Peter Katzmarzyk and I-Min Lee from the Pennington Biomedical Research Centre in Baton Rouge, Louisiana, also looked at the effect of total sitting time (including television watching) on life expectancy, in an article published in the journal BMJ Open.
They estimated that if people limited their sitting time to three hours a day, their life expectancy would increase by two years on average.
They looked at two studies in which people were asked how much time they spent sitting.
In the first, the Canadian Fitness Survey, participants were asked how much of their total waking hours they spent sitting. It found almost 50 per cent admitted to spending at least half their time sitting down.
In the second, an American study, volunteers were asked how much of their leisure time they spent doing so. It found similar results – that just over 50 per cent spent at least half their free time sitting down.
These results chime with a previous finding that the average American adult spends 7.7 hours a day sitting down.
Katzmarzyk and Lee concluded: “The results of this study indicate that extended sitting time and TV viewing may have the potential to reduce life expectancy in the USA.”
They said “a significant shift” in people’s behaviour, regarding cutting down on television watching and sitting down, was required “to make demonstrable improvements in life expectancy”.
David Spiegelhalter, Professor of the Public Understanding of Risk at Cambridge University, agreed.
He said: “It seems plausible that if future generations moved around a bit more, then they might live longer on average.
“But very few of us currently spend less than three hours sitting each day, and so this seems a very optimistic target.”
Source: Limit TV watching to 2 hours to live longer, say scientists – Telegraph