A new study validates your mother's concerns about too much television — watching four or more hours a day increases you chance of dying by 46 percent, regardless of whether you smoke, exercise, or have high blood pressure or heart disease. The Australian researchers found that each hour you spend in front of the glowing screen increases your chance of dying from cardiovascular disease by 18 percent, or from any cause by 11 percent. Is this just another x-will-kill-you study, or is it time to turn off the TV? (Watch a report about whether TVs pose health risks)

TV kills — you were warned: This is bad news for couch potatoes, says Lia Steakley at the Stanford University Scope, but the Australian scientists found that TV kills you faster "regardless of if you are overweight or physically fit." That's not to say weight isn't a factor: a Stanford team similarly found that TV negatively impacts your health, but also that "overweight adults who cut their daily television time in half burned 120 more calories a day."
"Research links watching TV to an increased risk of death"

Why does TV always get the blame? "There seems to be one of these studies every single year," says Bob Sassone in TV Squad. And for some reason, TV always "gets the blame" even though "they're trying to say that it's a sedentary lifestyle that increases the risk," not TV per se. But don't hold your breath waiting for them to "come and say 'reading books in a comfortable chair increases your risk of death by 9 percent.'"
"If you watch TV, you're going to die"

To live longer, lose the remote: Actually, the Aussie researchers acknowledge that the study probably also applies to sedentary activities such as "sitting in front of a computer, reading a book, driving, or taking the train to work," says Ron Winslow in The Wall Street Journal. So, watch TV if you must, but consider folding laundry at the same time or getting up to change the channel "rather than using a remote control."
"Watching TV linked to higher risk of death"

What's the point of living without TV? Look, "it's a dangerous world out there," says Nick Broughall at Gizmodo. So yes, "ultimately, you should know that your TV will kill you" — if you aren't killed in a plane crash or eaten by a shark, or whatever. But that's the larger point: "We’re all going to die anyway, so why not enjoy your life while you’ve got it?"
"Your TV is trying to kill you slowly"