TV viewing adds to Americans' sleep deficit

LOS ANGELES, June 8 (Xinhua) -- Too much TV viewing may be contributing to many Americans' chronic sleep deprivation, a new study has found.

Too much TV viewing may be contributing to many Americans' chronic sleep deprivation, a new study has found.(File photo)

TV -- rather than hours past sunset or biological signs -- has become the most important signal for sleep, according to the study presented on Monday at the Associated Professional Sleep Societies annual meeting in Seattle.

Staying up to catch the end of a favorite show may make people stay up later than they otherwise would, said the study.

In the morning, their alarm clocks may jar them awake earlier than they would naturally awaken, the study said.

These facets of modern life are potentially reducing sleep time below what is physiologically required, the study noted.

In the study, researchers at the University of Pennsylvania School of Medicine in Philadelphia looked at data about the sleep habits and bedtime rituals of 21,475 participants aged 15 or older who completed the American Time Use Survey between 2003 and 2006.

In the two hours around bedtime, TV viewing was the most common activity, accounting for almost 50 percent of the activities undertaken in the time before bed, according to the study.

"Given the relationship of short sleep duration to health risks, there is concern that many Americans are chronically under-sleeping due to lifestyle choices," study co-author David Dinges said.

Americans should watch less late-night TV and go to work later in the morning, the researchers suggested.

"While the timing of work may not be flexible, giving up some TV viewing in the evening should be possible to promote adequate sleep," said study co-author Dr. Mathias Basner.

Getting less than seven to eight hours of sleep daily can lead to impaired alertness and has been linked to higher rates of obesity, illness and death. Even so, up to 40 percent of Americans are not getting the recommended amount of sleep at night, according to the study.