Living a healthier, longer life may be simpler than you think. Eat well, exercise regularly and avoid bad habits.

Want the secret to living a longer and healthier life?  After finding ways to prolong the healthy lifespans of worms, mice, and even monkeys, scientists believe they are closer to finding the answer. They say decoding the biology of aging could be simpler than you think.

People born in the U.S. today can expect to live to an average age of about 79. A century ago, life expectancy was closer to 54. In addition, research has shown that older people tend to be healthier nowadays, as well.

“We’ve had a significant increase in lifespan over the last century,” says Dr. Marie Bernard, deputy director of NIH’s National Institute on Aging. “Now if you make it to age 65, the likelihood that you’ll make it to 85 is very high. And if you make it to 85, the likelihood that you’ll make it to 92 is very high. So people are living longer, and it’s happening across the globe.”

So how can you increase your chances of living a longer, healthier life? Experts say it’s a mix of good common sense, healthy habits, stress management and heredity.

“The vast majority of variation in how old we live to be is due to our health behaviors,” says Dr. Thomas Perls, an aging expert and director of the New England Centenarian Study at the Boston University School of Medicine. Perls has been studying people who live to age 100 and up (centenarians) and their families to learn more about the biological, psychological, and social factors that promote healthy aging.

You might think you need good genes to live longer, but genes are only part of the equation for most of us,

“Research shows that genes account for less than one-third of your chances of surviving to age 85,” said Perls. “Our genes could get most of us close to the remarkable age of 90 if we lead a healthy lifestyle.”

The influence of genes is stronger, though, for people who live to older ages, such as beyond 95.

“It seems there’s not a single gene that imparts a strong effect on the ability to get to these older ages,” Perls says. “Instead, it’s the combined effects of probably hundreds of genes, each with weak effects individually, but having the right combination can lead to a very strong effect, especially for living to the oldest ages we study.”

It’s also a good idea to be skeptical of claims for a quick fix to aging-related problems. Perls cautions against marketed “anti-aging” measures such as “hormone replacement therapy,” which has little proven benefit for healthy aging and can have severe side effects. Instead, he says we should stick to the tried-and-true methods: Eat well. Exercise regularly. Maintain a healthy weight. Get plenty of sleep, and avoid bad habits.

“If I had to rank behaviors in terms of priority, I’d say that exercise is the most important thing associated with living longer and healthier,” says Dr. Luigi Ferrucci, an NIH geriatrician who oversees research on aging and health. “Exercise is especially important for lengthening active life expectancy, which is life without disease and without physical and mental/thinking disability.”

Natural changes to the body as we age can lead to a gradual loss of muscle, reduced energy, and achy joints. These changes may make it tempting to move less and sit more. But doing that can raise your risk for disease, disability, and even death.

You don’t have to join a gym or do any elaborate workout. Brisk walking, strength and balance training, and flexibility exercises are enough to make a significant difference.

Another sure way to improve your chances for a longer, healthier life is to shed excess weight.

“Being obese—with a body mass index (BMI) higher than 30—is a risk factor for early death, and it shortens your active life expectancy,” Ferrucci says. BMI is an estimate of your body fat based on your weight and height.

Ferrucci recommends using NIH’s BMI calculator to determine your BMI and talking with a doctor about reaching a healthy weight.

Not smoking is another pathway to a longer, healthier life.

“There’s no question that smoking is a hard habit to break. But data suggest that from the moment you stop smoking, there are health benefits. So it’s worthwhile making that effort,” Bernard says.

Overall, experts say the key to healthy aging is to engage fully in life—mentally, physically, and socially.

“Transitioning to older years isn’t about sitting in a rocking chair and letting the days slip by,” Bernard says. “Older adults have unique experiences, intellectual capital, and emotional involvement that can be shared with younger generations. This engagement is really key to helping our society move forward.”