Bay Area residents are among the nation's longest-lived people, surviving on average more than a decade longer than residents of rural Kentucky, West Virginia or Mississippi.
Around the bay, we also top the charts in fitness, with rates of healthy weight and physical activity double those of the most obese and sedentary parts of the nation.
That is the revelation of a major new analysis of a University of Washington database widely regarded as the best county-by-county look at the landscape of health of America.
"Men and women in the Bay Area are doing stunningly well," said Bill Heisel, spokesman for the university-based Institute for Health Metrics and Evaluation, which published the most recent data in the journal Population Health Metrics to coincide with Michelle Obama's "Let's Move" campaign, to solve the problem of childhood obesity.
"The main drivers for premature death and disease are preventable," he said, through proper diet and exercise. "And the Bay Area is doing far better than the state and national averages" at staving off physical decline.
A glimpse of the national map shows a confluence of affluence and health. Like the Bay Area, regions of the U.S. with strong economies -- such as the suburbs of New York City, Washington, D.C., and Seattle -- tend to have high access to health care, open space, fresh fruits and vegetables and educational campaigns to reduce smoking, drinking and obesity.
Using data from 2010, the analysis shows that women in Marin, Santa Clara and San Mateo counties on average can expect to live more than 84 years -- comparable to those in Switzerland, Spain and France, countries with some of the highest life expectancies in the world.
The longest-lived people in the U.S. are women in Marin County, who live to an average age of 85 -- five years longer than the national average and 12 years longer than women in Perry, Ky., who lag behind women in Botswana. Although there are reports of elevated incidence of breast cancer in Marin, this does not significantly affect the county's average life span.
Men in Marin lived to an average of 81.4 years, 15 years longer than men in McDowell, W.Va., who themselves fare worse than men in Yemen, Sudan and Indonesia.
San Franciscans are among the leanest people in the U.S., the researchers found. Based on 2011 data, only 18.3 percent of men in San Francisco are obese -- the nation's lowest rate -- compared with a national average of 33.8 percent. For women, the San Francisco figure is 20.9 percent against a national average of 36.1 percent. In parts of Mississippi, almost 60 percent of women are obese.
Even within California, the data depicts wide ranges of longevity and health. In Lake County -- a beautiful but poor area surrounding Clear Lake, distant from medical specialists -- life spans lag five to eight years behind those of Bay Area residents.
Statewide, the prevalence of obesity rose from 24.1 percent in 2001 to 29.4 percent in 2011. Nationwide, it went from 26.1 percent to 33.8 percent.
Aside from obesity, however, almost all Americans are doing better on other benchmarks.
More people are running, biking and exercising in other ways than in 1985, when the data was first collected. People were considered physically active if they engaged in 75 minutes of vigorous exercise, such as a run, or 150 minutes of moderate exercise, such as a brisk walk, at least once a week.
There is also evidence of improved diets, with more fruits, vegetables and nuts. This translates into longer lives and less chronic disability from cardiovascular disease and diabetes.
Improved health and longevity were particularly pronounced in places like Alameda County, where the average life span climbed eight years over a 15-year span. That's a gain of more than six months of life every year.
"There have been improvements in the environment," such as air quality, said Dr. Muntu Davis, director of the Alameda County Department of Public Health.
But a major driver in increasing life spans is improved medical care of the ill and aged afflicted with chronic disease, he said.
"Advances in technologies and medicines are allowing people with chronic disease, such as hypertension, to live longer," he said.
By comparison, there was a gain of only three years in Lake County. And life spans barely budged at all in some parts of the rural South, the Mississippi basin, West Virginia, Kentucky and some counties with large Native American populations.
In Lake County, with the lowest ranking in California, "the root cause is socioeconomics, which is a major determinant of health," said Dr. Karen Tait, county health officer there. "People retire here and find issues with the cost of living, that they were not expecting," such as the high price for healthful drinking water from the lake. "If a retired person is living on Social Security and gets a high water bill, they have to make choices about medicines and proper nutrition."
There, as well as in other pockets of the U.S., residents must deal with unemployment and poverty, and higher rates of smoking, substance abuse and traffic accidents.
Lessons can be learned from the fitness, diet and access to care afforded those who live in the robust economy of the San Francisco Bay Area, the analysis shows.
"There is such a big gap still," Heisel said. "The Bay Area is doing amazingly well, but some parts of the U.S. are still struggling."
Contact Lisa M. Krieger at 650-492-4098.