Watch television at your peril. Too much time spent in front of the goggle box is associated with a significantly increased risk of both obesity and type II diabetes, according to a US study.
Despite the obvious attractions of Coronation Street, reality TV and wall-to-wall films, limiting the amount of time given to television viewing, combined with even a moderate level of activity, substantially lowers the risk of these conditions, according to research published today in the Journal of the American Medical Association.
The study included more than 50,000 adult women and looked at the links between couch-potato behaviours and the likelihood of becoming obese or developing type II diabetes, a condition strongly associated with being overweight.
The six-year analysis of this large group will be a matter of concern for anyone whose best friend comes with a wide screen. The study found that each two hours per day of television watching was associated with a 23 per cent increase in the risk of becoming obese. The same two hours was good for a 14 per cent increase in the risk of acquiring type II diabetes, according to Dr Frank Hu and colleagues from the Harvard School of Public Health and Brigham and Women's Hospital, Boston.
Watching television was the worst of a range of sedentary activities, according to an earlier study cited by Dr Hu. It found that sewing, playing board games, reading, writing and driving a car all used up more energy than staring at the tube.
However, even moderate activity can improve the statistical picture. Spending just two hours a day standing or walking around at home delivered a 9 per cent reduced risk in obesity and a 12 per cent reduction in diabetes, Dr Hu found.
Even better, each hour per day of brisk walking was associated with a 24 per cent reduced risk of obesity and a 34 per cent reduced risk of diabetes.
A survey carried out by Irish universities found adult men and women here spend on average 18.7 hours a week watching television and just 1.3 hours a week in "vigorous recreational activities". A similar study in the US showed adult men watching television 29 hours a week and women 34 hours per week.