TV or not TV (better yet, "to screen or not to screen"), that is the question.

Americans average more than seven hours a day of screen time on internet-connected devices, and TV time varies between less than two hours a day for teens and more than four hours daily for seniors.

But wherever you focus your attention, too much sitting around looking at screens is damaging your health. Two studies bring that into focus.

The first, published in the Journal of the American Heart Association, found that people with a familial risk for Type 2 diabetes are able to avoid their increased risk of cardiovascular disease if they limit their viewing time to an hour a day or less.

And whether that risk for diabetes-related heart disease is genetic or comes from lifestyle choices, spending two-plus hours daily watching TV increases the already-major risk of heart disease by an added 12%.

And around 100 million Americans are prediabetic, so excessive screen time is risky for almost a third of the population.

The second study in Frontiers in Psychiatry found that an hour's screen use after going to bed increases your risk of insomnia by almost 60%. Chronic insomnia is related to increased risk of high blood pressure, diabetes, obesity, depression, dementia, heart attack, and stroke.

Click. That's the sound of you turning off the screen — and understanding just how good for you that is.

For more help reducing your risks for diabetes and heart disease, check out the book "YOU: The Owner's Manual, revised edition."