Toronto: Too much television viewing makes you not only dull but also obese, according to a Canadian study.

The study, `Sedentary Behaviour and Obesity', has found a strong link between the number of hours spent watching television and the likelihood of being obese.

Based on the 2007 Canadian Community Health Survey involving 42,600 men and women aged 20 to 64, the study found that more time spent watching television increased obesity among both sexes.

"When factors such as age, marital status, education, household income, immigrant status and urban-rural residence were taken into account, the odds of obesity among men and women who reported watching television 21 or more hours a week were almost twice the odds for men and women who averaged five hours or fewer in front of the tube," Statistics Canada said, quoting the study.

The study also found link between time spent on computer and obesity among both sexes. It concluded: "Frequent computer users (11 or more hours per week) of both sexes had increased odds of obesity, compared with those who used computers for five or fewer hours per week."

It also found that even leisure-time computer use contributed to obesity among men and women.

"When age and other socio-demographic characteristics were taken into account, those who used computers for at least six hours a week had increased odds of being obese, compared with those who averaged no more than five hours," the study reported.

Curiously, the study found no link between reading (another sedentary activity) and obesity for either sex.

The study is line with other previous studies that have linked television viewing to obesity, irrespective of physical activity and dietary intake.