And the findings were sobering: Every single hour of television watched after the age of 25 reduces the viewer’s life expectancy by 21.8 minutes.
By comparison, smoking a single cigarette reduces life expectancy by about 11 minutes, the authors said.
Looking more broadly, they concluded that an adult who spends an average of six hours a day watching TV over the course of a lifetime can expect to live 4.8 years fewer than a person who does not watch TV.
Those results hold true, the authors point out, even for people who exercise regularly. It appears, Dr. Veerman says, that “a person who does a lot of exercise but watches six hours of TV” every night “might have a similar mortality risk as someone who does not exercise and watches no TV.”