Don't Overeat If you want to live to 100, leaving   a little bit of food on your plate may be a good idea. Author Dan Buettner,   who studies longevity around the world, found that the oldest Japanese people   stop eating when they are feeling only about 80% full. St. Louis University   researchers have confirmed that eating less helps you age slower; in a 2008   study they found that limiting calories lowered production of T3, a thyroid   hormone that slows metabolism—and speeds up the aging process.

Turn Off the TV Too much time in front of the   boob tube can take a serious toll on your health. In fact, a 2010 study found   that people who watched four or more hours a day were 46% more likely to die   from any cause than people who watched less than two hours a day. Even cutting   back a little can help; each additional hour you watch increases your overall   risk of dying by 11% and dying from heart disease by 18%.

Stay Out of the Sun Avoiding too much sun can   head off skin cancer, and it can also keep you looking young by preventing wrinkles,   fine lines, and saggy skin. It’s never too early—or too late—to add sunscreen   to your daily skin-care regimen (look for an SPF of 30 or higher). And don’t   focus only on your face. Sun damage spots and splotches on your chest and neck   will also make you appear older.

Reach Out Research shows that you’re at greater   risk of heart disease without a strong network of friends and family. Loneliness   can cause inflammation, and in otherwise healthy people it can be just as dangerous   as having high cholesterol or even smoking. Loneliness seems to pose the greatest   risk for elderly people, who are also prone to depression.

Drink in Moderation Women who have two or more   drinks a day and men who have three or more may run into detrimental effects   ranging from weight gain to relationship problems. But in smaller quantities,   alcohol can actually be good for you. A 2010 study in the Journal of the American   College of Cardiology linked light drinking (defined as one drink a day for   women and two for men) to significant heart benefits.

Eat Fruits and Vegetables Getting fewer than three   servings of fruits and vegetables a day can eat away at your health. Nutritional   powerhouses filled with fiber and vitamins, fruits and veggies can lower your   risk of heart disease by 76% and may even play a role in decreasing your risk   of breast cancer. As an added bonus, the inflammation-fighting and circulation-boosting   powers of the antioxidants in fruits and veggies can banish wrinkles.

Focus on fitness Daily exercise may be the closest   thing we have to a fountain of youth. A 2008 study found that regular high-intensity   exercise (such as running) can add up to four years to your life, which isn’t   surprising given the positive effects working out has on your heart, mind, and   metabolism. Even moderate exercise—a quick, 30-minute walk each day, for example—can   lower your risk of heart problems.

Don't Smoke Quitting smoking is perhaps the single   most important thing you can do for your health—and your life span. A study   published in the American Journal of Public Health found that women who quit   smoking by age 35 add roughly six to eight years to their lives. It’s never   too late to kick the habit. Quitting can slow disease and increase survival   odds even in smokers who have already caused significant damage to their lungs,   like those with early lung cancer or COPD.