We’ve heard all the negative stuff about TV, including its negative impact on health. But maybe there’s some positive health benefits to come out of it too. From Seed Magazine:
Humans are made to move. Even just a century ago, few people spent their entire workday just sitting at a desk. Passive entertainment, too, is a relatively new innovation. Televisions have been widespread for barely 60 years. Radios, for less than a century. Books, for perhaps half a millennium. Sure, music and theater have existed for longer than that, but attending a live performance still involved trudging to the amphitheater or town square, sitting or standing on uncomfortable benches, and then making the same journey back home. And more people were likely to participate in making the music or plays when they couldn’t be recorded and electromagnetically transmitted through the air. Out of the hundreds of thousands of years Homo sapiens has existed, we’ve been intensely physically active for all but a few of them.
So clearly moving around is an important part of being human. When we don’t move our muscles quickly atrophy, and life-sapping deposits of fat build up around our vital organs. When we lose physical fitness we live shorter, disease-ridden lives.
Travis Saunders, a PhD student at the University of Ottawa who studies the impact of sedentary lifestyles, questions whether a little exercise can make up for hours of inactivity. He refers to a study led by G.F. Dunton of the University of Southern California and published in October in the International Journal of Obesity. The researchers conducted a phone survey of 10,000 Americans who ranged from normal weight to obese. As you might expect, people who engaged in a lot of physical activity tended to weigh less than those who did not.
But when the researchers considered how much time these individuals spent watching TV and movies, a different pattern emerged. No matter how much TV they watched, if they didn’t exercise, they had high BMIs (body mass index—a measure of obesity). But even among people who exercised more than an hour a day, those watching more than an hour of TV per day had significantly higher BMIs than those who did not. In fact, for respondents who watched more than an hour of TV, whether or not they exercised no longer predicted BMI.
Does this mean that watching TV and movies makes you overweight, regardless of how much exercise you get? Not necessarily—this is just a correlation, not a controlled experiment. It could be that some other factor is responsible. It might be that people with higher BMIs just like TV more. Or that they are eating and drinking more while they watch TV, compared to other activities.