Eat better.

It's not really rocket science. You're supposed to eat more vegetables, fruits and whole grains and less fried, salty and sugary stuff (and watch that soda; even diet pop is associated with weight gain). It's easy (meaning straightforward), but it's hard (meaning difficult to apply), so get educated and consider getting some support. The American Heart Association and the American Stroke Association have some information here.

Watch your back (and your joints).

Losing weight and getting regular exercise can ease many back and joint problems. (Talk with your doctor about what kinds of exercise make sense; those with knee problems, for example, might be better off doing aerobics in a pool than on land.) Something as basic as learning how to lift properly can help you avoid back trouble; bend your knees and hips until you are squatting, keeping your back straight, then lift with your leg muscles.

Get screened.

My mom might be here today if she'd gotten the colonoscopy that doctors now recommend at age 50. (Lower that to age 40 if you have a relative who developed cancer.) Women need mammograms and cervical exams, men need prostate exams. Regular checks of your blood pressure, cholesterol levels, skin (for skin cancer) and teeth are important. Your doctor can help guide you on what you need and when.

Let the screens go dark.

Australian researchers found that increasing your television viewing increases your risk of dying from cardiovascular disease. Even more disturbing, the researchers found that people who spent four or more hours a day in front of a television or a computer had an 80% increased risk of cardiovascular-disease-related death compared with those who watched less than two hours a day. The risk remained even after researchers subtracted the effects of common heart disease risk factors, such as smoking, high blood pressure, high blood cholesterol, bad diet and a big belly. Which means you could be thin, healthy, even a regular exerciser and still face a higher risk of death because of your time staring at a screen. So get up and move. (A bonus from turning off the television is that you don't have to watch all the commercials featuring high-fat and otherwise unhealthy food.)

Use drugs carefully.

Unintentional poisoning is second only to motor vehicle crashes as a cause of unintentional injury death, according to the Centers for Disease Control. Among people 25 to 64, unintentional poisoning actually caused more deaths than motor vehicle crashes. And nine out of 10 unintentional poisoning deaths involve drugs. Prescription painkillers, which includes such drugs as methadone, hydrocodone and oxycodone, were most commonly involved in deadly poisonings, followed by cocaine and heroin. So don't think that you're safe just because you don't use illegal drugs. If you're prescribed a drug, follow the directions. If you can't or can't stop, get help.

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Don't neglect your mental health.

Exercise can improve your mood, but it's not a bulwark against serious depression, anxiety, phobias or other mental illnesses. And mental illness is far more common than you might think. One in four U.S. adults experiences a diagnosable mental disorder in any given year, according to the CDC, and 46% of Americans will suffer from a mental disorder in their lifetimes. Early intervention and treatment can make a big difference.

Liz Weston is the Web's most-read personal-finance writer. She is the author of several books, most recently "The 10 Commandments of Money: Survive and Thrive in the New Economy" (find it on Bing). Weston's award-winning columns appear every Monday and Thursday, exclusively on MSN Money. Join the conversation and send in your financial questions on Liz Weston's Facebook fan page.