Ken Fujioka grew up on a farm in Leucadia where he ate well, but was busy doing lots of chores, burning calories. During his undergraduate years at San Diego State College, and his years at the University of Hawaii medical school —— despite his participation in sports and surfing —— the pounds crept on.

He tried different ways to control his weight —— diet, exercise, being a vegetarian —— but like many folks, his girth yo-yoed up and down.

Then he started developing medical problems.

"I thought I really needed to get control, so I started looking at (the problem) scientifically," he said. "I went back to graduate school to learn more about nutrition and metabolism, and that's when it became my life's work."

Dr. Fujioka is a member of the Division of Diabetes and Endocrinology at Scripps Clinic in Del Mar. At age 51, the Cardiff resident has both first-hand experience and professional knowledge of what it takes to stay strong and have a healthy lifestyle as you age. Fujioka has extensive experience in medical problems of both underweight and overweight individuals, and he works extensively with problems such as slow metabolism, eating disorders and high cholesterol.

Nutrition issues became his life's work in the 1980s, he said, and he has found that the right changes at the right stages can substantially enhance one's quality of life.

There's an old saying that goes, "If I'd known I was going to live so long, I'd have taken better care of myself." Well, living longer is becoming a trend in America. Life expectancy for Americans has reached an all-time high, according to the latest U.S. mortality statistics released last week by the Centers for Disease Control and Prevention.

The report, prepared by CDC's National Center for Health Statistics, shows life expectancy at 77.6 years in 2003, up from 77.3 in 2002.

With that expectation, experts agree that it's never too soon to begin taking better care of yourself.

Once you've passed the 50-year marker, said Dr. Pamela Peeke of the Discovery Channel's National Body Channel, your goal should be to live for another 50 years.

"The challenge is to maintain a healthy foundation, just when your body is running into wear-and-tear problems —— your knees creak, your back hurts and the incidence of heart disease, diabetes and cancer gradually increases," she wrote on the Body Channel Web site (www.discoveryhealth.com). "The key is to attain optimal endurance, strength and flexibility to live well and long." Avoid fad diets, she said, and treat foods like a precious medicine cabinet of anti-oxidants and powerful disease-fighting nutrients.

Studies have shown the impact of aging on health can be different for men and women, Fujioka said. For instance, women most typically go into menopause at age 50 or thereabouts, and that contributes weight gain, he said.

"This is a really tough time for women. They can gain up to 10 pounds. Men gain beginning at age 55, and then their weight levels off and they don't gain after that."

Women also have a metabolic rate that's 30 percent slower than that of men, and those who have had multiple births have even slower metabolic rates. "It's the wisdom of survival that if you have multiple children, you need to be able to live on just a few less calories," he said.

Another problem that develops with age is that the teeth may not be as strong or the bowels as efficient, so people gravitate to more processed foods, he said. Adding fresh fruits and vegetables to the diet provides much-needed nutrients —— vitamin C, magnesium, potassium —— all things that we need to function as we age, he said.

Living in the San Diego area means fresh produce is available year-round, he said. And, although some people are on a fixed budget, the benefits can be worth a sacrifice.

The younger you are when you make lifestyle changes to keep your weight down, and get them ingrained, the better, he said.

"Not making the changes can hurt your quality of life," he said. "You're on more medications, and if you're seriously overweight in your late stages, you end up in a nursing home sooner. Make the changes as soon as you can. Don't keep putting it off."

Best advice?

"You need to weigh yourself," he said. "Don't put the scale away. Don't hide it. Eat breakfast. Mom was right. Stay as active as you possibly can."

In the early 1900s, the average person lived to his or her 40s, said Denise Nelesen, spokesperson for Aging & Independence Services, a county program that provides services to older adults and people with disabilities to help promote healthy and vital living.

"The history of human existence hasn't seen so many older people," she said. "They are out there and pioneering, so look out."

Being involved, more than anything, is the key to being healthy in the later years, Nelesen said. "They need to be involved in interesting and challenging and feel-good stuff."

If your image of an older adult is one of walkers and medications and such, not only will you dread it, you might be leading yourself to that path —— a self-fulfilling prophecy.

The definition of healthy aging depends on what age group you're talking about, Nelesen said.C"We're kind of making it up as we go along. The baby boom generation is about to turn 60. They have always led the social movements.

"They're going to lead a whole new view of what it's going to mean to be an older adult."

Contact staff writer Agnes Diggs at (760) 740-3511 or adiggs@nctimes.com.