Remember all those times your mom chastised you for "wasting your life" watching TV? Turns out that she might not have been overstating the issue.

Australian researchers have concluded that "on average, every single hour of TV viewed after the age of 25 reduces the viewer's life expectancy by 21.8 minutes." That's 21 minutes and 48 seconds, for those of you not into the metric system.

The study, done at the University of Queensland, is believed to be the first of its kind. Other studies have focused on the relationship between TV viewership and health issues such as obesity, but this is the first research that has drawn a direct line between viewing habits and life expectancy.

The researchers, admitting that the process involved a high degree of conjecture, modeled actuarial tables on data from the Bureau of Statistics (the Aussie census) and the Diabetes, Obesity and Lifestyle Study, a national health survey first conducted in 2000 and followed up in 2005 and 2010. They said that they're not blaming TV viewing per se for shortening lives. The culprit is the sitting that typically accompanies the viewing.

The findings were what she would have expected, said Amanda Wittig, a weight-loss specialist and personal trainer at the Life Time Fitness Club in Maple Grove.

"If you think about what watching television is considered -- a sedentary activity -- then it comes as no surprise that an increase in watching television decreases your life expectancy," she said. "Individuals that are less active and live a sedentary lifestyle have always been at a greater risk for acquiring cardiovascular disease and other health related issues."