Obesity in the United States has grown "faster than anyone could have imagined," doubling in adults and tripling in children in recent years, a leading health official said Tuesday.
The number of states where more than 30 percent of residents are obese tripled, from three to nine, between 2007 and 2009, Dr. Thomas Frieden, the head of the Centers for Disease Control and Prevention (CDC), told reporters as he released data from the 2009 Behavioral Risk Factor Surveillance System (BRFSS).
The BRFSS has been tracking health conditions and risk behaviors in the United States yearly since 1984.
This year, added Frieden, not one state managed to achieve a goal set by health officials to cut the rate of obesity to 15 percent or less.
Instead, an additional 2.4 million US adults self-reported to the BRFSS that they were obese, pushing the national obesity rate up by 1.1 percentage points to 27 percent, according to the BRFSS.
BRFSS statistics put the obesity rate lower than the 34 percent prevalence reported by the National Health and Nutrition Examination Survey (NHANES).
Frieden blamed the difference on the data collection methods used by each survey: BRFSS is self-reported while "in NHANES, participants are weighed and measured."
Obesity is defined as having a body mass index -- calculated by dividing a person's weight in kilograms by their height squared in meters -- greater than 30.
In health terms, it means a person is at greater risk for a whole host of maladies, ranging from high blood pressure to diabetes, heart disease and stroke.
The rising rate of obesity in the United States is driving up medical costs as complications from the condition, including heart disease, stroke, diabetes and cancer, sicken and kill more and more people, said Frieden.
In 2008, medical costs associated with obesity were estimated at 147 billion dollars, Frieden said.
"That translates into medical costs for people who are obese that were 1,429 higher per person each year compared to normal-weight individuals," he said.
A separate study published Tuesday in the American Journal of Preventive Medicine found that the percentage of obese adults in the United States shot up by 90 percent in 16 years, from 14 percent in 1993 to 27 percent two years ago.
That study, based on data from the 1993-2008 BRFSS, showed that more American men and women from every ethnic group were dying younger or suffering ill health because they were obese.
Obesity's steep growth curve is not uniquely American, Bill Dietz, director of the CDC's division of nutrition, physical activity and obesity, said at the news conference with Frieden.
"We have a very high prevalence but a couple of years ago I compared the rate of rise of obesity in women in the UK versus women in the United States," Dietz said.
"The curves were parallel," he added, blaming the international growth of girth on a cultural shift that has made "high-calorie food more readily available and reduced opportunities for physical activity."