Watching too much TV really can kill you, researchers reported on Tuesday.
And it doesn’t take much—for every two hours of TV watching a day, another extra 104 people out of 100,000 will die of something, and 38 out of 100,000 people will die of heart disease, Danish and U.S. researchers reported in the Journal of the American Medical Association.
People who watch TV for just two to three hours a day raise their risk of diabetes, heart disease, and death in general, Anders Grontved of the University of Southern Denmark and Dr. Frank Hu of the Harvard School of Public Health found. This is far less than the U.S. average of five hours a day reported by Nielsen for 2010.
“Television viewing is the most commonly reported daily activity apart from working and sleeping in many populations around the world,” Grontved and Hu wrote. “On average, 40 percent of daily free time is occupied by TV viewing within several European countries and 50 percent in Australia,” they added—and even more in the United States.
Grontved and Hu did what is known as a meta-analysis, grouping together several studies of more than 175,000 people who detailed their TV viewing habits and whose disease rates and deaths were tracked.
They found that every two hours of daily TV viewing time was associated with a 20 percent higher risk for type 2 diabetes; a 15 percent increased risk for fatal or nonfatal heart disease; and a 13 percent higher risk for all causes of death. “The risk of all-cause mortality appeared to increase with TV viewing duration of greater than 3 hours per day,” they wrote.
The United States has soaring rates of heart disease and diabetes, and policymakers in government as well as public-health experts are trying to get Americans to change their habits. Heart disease is the No. 1 cause of death and diabetes is No. 7. Treating Americans with these chronic conditions has helped boost health care costs to more than 17 percent of gross domestic product. The United States already has the highest per-capita health care costs in the developed world.
The American Heart Association said earlier this year that the costs of heart disease in the United States will triple between now and 2030, to more than $800 billion a year.
Obviously, people who sit and watch TV are not exercising, but Hu and Grontved said there is more to it than that.
“Beyond altering energy expenditure by displacing time spent on physical activities, TV viewing is associated with unhealthy eating (e.g., higher intake of fried foods, processed meat, and sugar-sweetened beverages and lower intake of fruits, vegetables, and whole grains) in both children and adults,” they wrote.
And they pointed to studies that showed cutting back on TV time caused overweight children to lose weight without necessarily making them exercise more.