There's a key culprit in the battle against sitting. Time spent watching TV and videos has remained consistently high in the United States over the past 15 years, but time sitting at a computer has increased dramatically, new research finds.

Axar.az reports citing Leisure-time computer use increased between 4.8% and 38% for various age groups between 2001 and 2016, said Yin Cao, senior author of the new study and an assistant professor of surgery at Washington University School of Medicine in St. Louis.

Overall, up to 43% of the US population used a computer for two or more hours a day and up to 25% used a computer for three or more hours each day in 2016.

The result of these increases: Teens spent about 8.2 hours a day sitting while adults sat for 6.4 hours a day.

Both groups saw a one-hour increase over the decade ending in 2016, Cao said.

Cao believes that her research, published Tuesday in JAMA, will help Americans better understand our sedentary habits -- and change them.

Sitting trends over the past 15 years

"Research evidence has been growing on the association between sedentary behavior -- primarily TV watching -- and a variety of diseases, including obesity, cardiovascular disease, cancer, Type 2 diabetes and overall mortality," Cao said.

For the first time, the US Department of Health and Human Services mentioned in last year's edition of its physical activity guidelines "that people would benefit from both increasing moderate to vigorous activity and also reducing time spent sitting," she said.

She wondered: How much do Americans sit, and how has the trend changed over the past 15 years? To answer these questions, Cao and her co-authors used data from the National Health and Nutrition Examination Survey on 51,896 people -- 10,359 children, 9,639 teens and 31,898 adults -- from 2001 through 2016.

Overall, up to 65% of the population reported watching TV for at least two hours each day, the study found. "This is quite high and has been overall stable over the past 15 years," Cao said. Computer time, though, has been increasing over that same period.

Just 43% of children reported using a computer for one hour per day or more in 2001; that rate increased to 56% in 2016, the study indicates. The estimated prevalence for teens increased from 53% to 57%, and for adults it went from 29% to 50% between 2003 and 2016. Only adults and teens reported their total sitting time.

"Hopefully, this paper will be helpful in terms of setting the national achievable goal of reducing sitting, given that we already know prolonged sitting is bad for many health outcomes," Cao said.