Since its debut at the World’s Fair in 1939, the square box has become a mainstay in the majority of American households. It’s our source for news, entertainment, and nail-biting dramas, and life without TV for many would feel a little strange and perhaps, empty. We all have our favorite shows (House of Cards anyone?), but is our love of TV damaging our health and is there a limit to how much we should be watching?

Tuning In — Why It Matters

The average American spends up to 34 hours a week watching live TV. Traditionally, younger adults tend to watch less TV than older folks, but there’s evidence that the under-35 crowd is becoming more and more likely to watch TV shows on computers and mobile devices. In fact, research suggests people between the ages of 18 and 34 watch more than two hours of Internet or mobile video per week, in addition to the average 23 hours they spend tuned into live TV.

Some research suggests that all this time watching TV, whether it’s on the traditional tube or on a smartphone, may be taking a negative toll on our health. One study found that for every hour spent watching TV, our life expectancy decreases by 22 minutesTelevision viewing time and reduced life expectancy: a life table analysis.Veerman, J.L., Healy, G.N., Cobiac, L.J., et al. British Journal of Sports Medicine 2012 Oct;46(13):927-30.. (To put that into perspective, for every cigarette smoked, life expectancy supposedly decreases by 11 minutesTime for a smoke? One cigarette reduces your life by 11 minutes. Shaw, M., Mitchell, R. BMJ 2000 January 1; 320(7226): 53..)

That’s possibly because watching TV is often part of a relatively unhealthy lifestyle, characterized by insufficient physical activity and poor eating habits. One study found that kids who watched a lot of TV were more likely than others to eat junk food and less likely to eat fruitAssociations of television viewing with eating behaviors in the 2009 Health Behaviour in School-aged Children Study. Lipsky, L.M., Iannotti, R.J. Archives of Pediatrics & Adolescent Medicine 2012 May;166(5):465-72.. Interestingly, other research suggests that TV advertisements motivate kids to choose less healthy foods, and not the act of watching TV itselfAssociations of television content type and obesity in children. Zimmerman, F.J., Bell, J.F. Department of Health Services, University of California, Los Angeles, Los Angeles, CA, USA. American Journal of Public Health 2010 Feb;100(2):334-40.

But spending every night on the couch watching Girls and chowing on Cheetos is unlikely to put a smile on anyone’s face. One study that analyzed over 30 years worth of data found those who watched the least amount of TV reported being happier than other people. Kids and adults who don’t watch a lot of TV are also more likely to go out and socialize than those stuck in front of the tubeTime well spent? Relating television use to children’s free time activities. Vandewater, E.A., Bickham, D.S., Lee, J.H. Human Development and Family Sciences, University of Texas, Austin, TX, USA. Pediatrics 2006 Feb;117(2): e181-191.. It’s hard to know whether TV directly causes unhappiness or vice versa, but researchers suggest that unhappy people tend to choose activities that are passive and provide an escape from daily life, like watching TV. Still, it’s possible for TV to be part of a healthy lifestyle.

Your Brain on TV — The Answer/Debate

When it comes to TV, the type of programming we watch may be just as important as how much we watch. Research suggests kids who watch educational programs perform better academically as adolescents than those who watch violent programs and other kinds of TV showsEarly childhood television viewing and adolescent behavior: The recontact study. Anderson, D., Huston, A., Schmitt, K., et al. Monographs of the Society for Research in Child Development 2001;66(1):I-VIII, 1-147.. Even in the short term, there are certain circumstances in which watching TV can help boost our brainpower. One study found people who watched an episode of TV right before taking a test performed better than those who did a crossword puzzle, played with a toy, or listened to classical music. Other research found those who watched TV shows (including the Simpsons) had a better understanding of political issues right afterward. It’s possible that watching TV relaxes us, making us more open to new ideas.

Ultimately, no one’s saying TV is bad for our health. The problem might lie more with what is happening while we’re watching TV, like spending a lot of time sitting down and mindlessly munching. Instead of putting the TV on eBay, try tuning into a program that teaches us something, like a cooking show or a historical documentary. While watching, avoid sitting in the same position we’ve been in all day and try standing or lying on the stomach in a cobra-like position. Then use every commercial break as a reminder to get up and do something physical, like squats or foam rolling.

How much TV do you watch? Do you think the habit is taking a negative toll on your health? Let us know in the comments below or tweet the author at Aaron_Morton.