Did you know that watching one hour of TV could shorten your life by 22 minutes? That’s because even if you get plenty of exercise, too much sitting increases your risk of diabetes, weight gain and a weakened immune system, as well as cancer and heart disease. All of which raise your risk of an early death.

In the study, researchers followed 11-thousand people over the age of 25 for a decade. The result: One hour of TV reduced life expectancy by 22 minutes, exactly the same as smoking 2 cigarettes…… Which means, watching 4 hours of TV a day, which is the average, can cut more than 3 years off your life.

So, why is watching TV so bad? Because it puts us into a trance-like state and slows down our metabolism. In fact, studies done by the Harvard School of Public Health show that television slows down our metabolism more than reading, surfing the web, sitting in traffic, or playing solitaire. The only activity that does less for our metabolic rate is sleeping. But that hypnotized feeling you get in front of the tube has a biological basis. The constant moving images trigger what's called an "orienting response.”

That means our heart rate slows down, our muscles relax and blood vessels in our brain dilate as our bodies try to figure out what's going on. This reaction is so instinctive, that infants lying on their backs will crane their necks nearly 180 degrees to watch television.