Study finds that one-quarter of California adults are obese

More Californians than ever are obese, according to a new report by the UCLA Center for Health Policy Research.

The study found that 24.8 percent of adults were obese in 2011–12, compared to 19.3 percent a decade earlier. Nearly 18 million California adults and adolescents are considered overweight or obese, and about 7.4 million of them can be classified as obese. Data for the research was drawn from California Health Interview Survey results starting in 2001. Adults with a body mass index of 25 or greater are considered overweight; those with a BMI of 30 or more are considered obese.

The authors also found that 16 percent of Californians ages 12 to 17 were overweight and 17 percent were obese—both figures were relatively unchanged from 2001. Nearly 1 million California adolescents were overweight or obese in 2011–12.

Nationally, 28 percent of adults are obese, according to Behavioral Risk Factor Surveillance System data. Although the California average is slightly below that figure, the UCLA study found that obesity rates in 17 of 41 California counties or county groups are at or above the national level. (The researchers grouped some smaller counties into groups in order to make data sample more robust.)

"Healthy eating requires a combination of money, time and resources, which not everyone has," said Joelle Wolstein, a research scientist at the center and lead author of the study. "Obesity results from a complex web of factors. Can you get fresh vegetables nearby? If not, can you get to the store? Is there a safe place to exercise nearby?"

The study, funded by The California Endowment, found obesity rates had increased in every major region of the state since 2001. But current adult obesity rates varied widely by county: San Francisco County had the lowest rate (11.3 percent), while Imperial County had the highest (41.7 percent).

Counties and county groups with the highest and lowest adult obesity rates in 2011–12:

Lowest

• San Francisco: 11.3%
• San Luis Obispo: 12.6%
• Marin: 13.9%
• San Mateo: 16.6%
• Yolo: 17.9%

Highest

• Imperial: 41.7%
• Tehama/Glenn/Colusa*: 38.2%
• Tulare: 38.0%
• Kings: 36.6%
• Solano: 35.9%

* Smaller counties were pooled to create a larger sample.

A sortable, county-by-county list is available on the UCLA Center for Health Policy Research website. 

"It's a bit ironic that the counties with the highest obesity rates tend to be rural," said Susan Babey, a senior research scientist at the center and co-author of the study. "We associate the countryside with fresh fruits and vegetables, but these may be the places where it's hardest to access a healthy diet."

Most vulnerable more likely to be obese

Lower-income Californians and those belonging to certain racial and ethnic groups had disproportionately high rates of obesity, the report found. Obesity rates among the poorest adults —those with household incomes below 200 percent of the federal poverty level—jumped during the past decade from 24.4 percent to 30.5 percent, a rate 10 points higher than that of higher-income Californians (those whose income was at least 400 percent of the poverty level).

Obesity rates also varied considerably by race, although the figures for all racial and ethnic groups increased during the decade. Groups with the highest obesity rates in 2011–12 were Pacific Islanders (37.1 percent), American Indians (36.2 percent), African-Americans (36.1 percent) and Latinos (32.6 percent)—all markedly higher than the rate for whites (21.9 percent). Asians had the lowest obesity rate, 9.7 percent, but even that figure represented a jump from 5.3 percent in 2001.

Rates within racial groups varied significantly, as well. Among Asian subgroups, for example, 2.1 percent of Koreans were obese versus 20 percent of Southeast Asians.

Contributing factors

Predictably, those with unhealthy dietary behaviors—a limited diet of fresh produce and high consumption of sugary beverages and fast food—had higher rates of overweight and obesity. But the study found that other social, demographic, economic and environmental factors played important roles, too. Some examples:

• Access to fresh produce: 22 percent of adults who said fresh produce was always affordable in their neighborhood were obese, compared with 31 percent of those who said fresh produce was never affordable. Only three-quarters of Latinos and African-Americans said fresh produce was affordable, compared to 86 percent of whites.
• Neighborhood safety: Among low-income adults, 28 percent felt their neighborhood was unsafe compared to 5 percent of higher-income adults. Twenty-two percent of Latinos and 18 percent of African-Americans reported their neighborhoods were unsafe compared to 7 percent of whites.
• Park safety and exercise: Among adolescents, 27.4 percent of those who felt their neighborhood park was safe were obese; the obesity rate among adolescents who felt their park was unsafe was 42.3 percent.
• Social connection: 26 percent of those who felt little connection with neighbors were obese, compared with 22 percent of those in high-connection neighborhoods.

The authors write that local governments should address these barriers by bringing more farmers' markets to underserved areas or by offering incentives to storefront markets to add fresh produce; improving safety at existing parks through better maintenance; developing crime prevention programs to encourage leisure walking; making neighborhoods more walkable and pedestrian-oriented; and encouraging development projects that include recreation space.

"Low-income communities lack resources such as parks, grocery stores, health clubs and, even in many instances, sidewalks, of which wealthier communities have an abundance," said Dr. Robert Ross, president and CEO of The California Endowment. "It's the lack of equity between low-income communities and their wealthier counterparts that is helping to drive the disparities in obesity rates in California and across the nation, and this report confirms that."