I don't imagine anyone kidded themselves that sitting in front of the TV for hours was good for their health, but it's not always easy to quantify the effects. However, Australian and French scientists have come up with some figures, and they don't look pleasant for couch potatoes.
Picture by lexrex
Leigh Dayton at the Australian reports that the study found that people who watch television more than four hours a day have a 46% higher chance of dying prematurely. Nick at Gizmodo makes the point that you're going to die anyway, which is fair enough -- and if TV is a useful form of stress relief for you, that might offset the other risk might be worth it. Also, watching French television is a pretty dangerous prospect at any time.
That said, the potential solution is ridiculously simple: stand up more often, as researcher Dr David Dunstan told the paper:
Too much sitting is bad for your health. Stand up. The more you move, the greater the health benefits.