The nation's waistline is expanding -- with nine states reporting more than 30 percent of their residents are obese -- a far cry from 10 years ago when not one state had such a high prevalence of obesity, researchers at the U.S. Centers for Disease Control and Prevention say.
Not one state in the U.S. has met the national goal of lowering obesity prevalence to 15 percent, reported Dr. William Dietz, director of nutrition, physical activity, and obesity for the CDC, and colleagues.
Only one state -- Colorado -- and the District of Columbia reported a prevalence of obesity under 20 percent (18.6 percent and 19.7 percent, respectively), according to the CDC's second MMWR "Vital Signs" report on the issue.
"In 2007, only three states reported an increased prevalence of obesity above 30 percent -- Tennessee, Alabama, and Mississippi," Dietz said during a telephone press conference.
"Now, there are nine states that exceed [that mark]: Missouri, Kentucky, West Virginia, Tennessee, Arkansas, Oklahoma, Louisiana, Mississippi, and Alabama."
Mississippi had the highest prevalence, at 34.4 percent, and obesity estimates were ostensibly higher in the Midwest and South.
The data come from the agency's Behavioral Risk Factor Surveillance System (BRFSS), which collects self-reported health data via telephone interviews by state health departments.
Dietz cautioned that the self-reported data likely underestimated the prevalence of obesity -- because research has shown that both men and women overestimate their height and women underestimate their weight.
In fact, the national obesity estimate in this study stood at 26.7 percent -- lower than the 33.9 percent prevalence reported by the latest analyses of data from the National Health and Nutrition Examination Survey, in which height and weight are physically measured.
Still, the BRFSS data showed a 1.1 percent increase in prevalence from 2007, which translates to an additional 2.4 million people who are obese.
And Dietz said that both surveys point out that obesity disproportionately affects certain groups.
The BRFSS data found higher obesity rates among:
Non-Hispanic blacks: 36.8 percent
Hispanics: 30.7 percent
Individuals who didn't finish high school: 32.9 percent
Patients ages 50 to 59: 31.1 percent
Patients ages 60 to 69: 30.9 percent
Dietz said it's not clear why Colorado and the District of Columbia have the lowest rates of obesity, but he noted that two-thirds of the Colorado population lives in Denver -- dubbed the "mile-high city" because it is located one mile above sea level.
People who live at such high altitudes expend more energy even for normal daily functioning, Dietz said, and Colorado has long invested its lottery funds in physical activity initiatives such as parks and trails. "It has more of a culture of physical activity than other states," he commented.
Data for the District of Columbia are a bit more perplexing, Dietz said, because it has a large African-American population at risk for obesity. At the same time, city dwellers rely more on the district's public transportation system, and subway riders tend to use more energy, he added.