By Rob Stein
Washington Post Staff Writer
Thursday, November 29, 2007
The obesity epidemic that has been spreading for more than a quarter-century in the United States has leveled off among women and may have hit a plateau for men, as well, federal health officials reported yesterday.
While the proportion of adults who are obese remains high at more than 30 percent, the rate in 2005 and 2006 was statistically unchanged from the last time government researchers took a national snapshot two years earlier.
The findings confirm earlier indications that the increase in obesity among women had stalled and suggests that the same trend may have begun among men.
"This is encouraging," said Cynthia L. Ogden of the National Center for Health Statistics, which released the new data. "I think we can say that obesity in women is stabilizing, and I'm optimistic that we may be seeing a leveling off in men, as well."
If both trends continue, it could mean that the effort to stem the nation's growing girth could be starting to pay off, Ogden and others said.
"This doesn't show we've turned the corner on obesity, but we might be at the corner," said William H. Dietz of the Centers for Disease Control and Prevention (CDC). "The first step in controlling any epidemic is halting a rise in the number of cases, and this suggests that might be happening."
But experts quickly cautioned that it is too soon to declare victory, noting that the lull could be fleeting and that about 72 million adults are still considered obese.
"This is still the biggest health problem of our time," Gary D. Foster, director of obesity research and education at Temple University, who is president of the Obesity Society, said. "It's not time to relax. We've got to continue to take the problem seriously and be aggressive about finding effective prevention and treatment strategies."
The proportion of Americans who are obese has increased dramatically in the last 25 years, doubling among adults and tripling among children since 1980. Because obesity increases the risk of heart disease, cancer, diabetes and other major health problems, the rapid rise has alarmed health experts.
Ogden and her colleagues reported last year that the National Health and Nutrition Examination Survey, an ongoing program tracking obesity and other major health issues, showed that the increases may have stalled for American women in 2003 and 2004. But they said more data were needed to confirm whether the shift was real.
The latest data collected from a nationally representative sample of 4,400 Americans age 20 and older showed that, while the proportion of women who were obese increased from 33.2 percent in 2003 and 2004 to 35.3 percent in 2005 and 2006, that difference was not statistically significant, and the rate has been stable since 1999.
Among men, Ogden and her colleagues found that the rate increased from 31.1 percent to 33.3 percent, but that change, too, was not statistically significant. But because the rate was still up compared with 1999, Odgen said more data are needed to confirm the stall.
"I'm optimistic, but I'm wary about the trend for men until we see more data," she said.
Ogden said the reasons that the epidemic might be easing were unclear, but some have speculated that the nation may have reached a saturation point, where most of those predisposed to obesity have already got there.
"Maybe we've gotten as heavy as we can," she said.
Efforts to get people to exercise more and eat better may also be starting to pay off, the CDC's Dietz said.
"I think people are paying attention more to nutrition and physical activity around the country," said Dietz, citing data released last week showing a rise in exercise rates and indications that eating patterns are improving and more employers are focusing on helping employees control their weight.
It is also unclear why women appear to be leading the way, outpacing men at first in gaining weight but now leveling off while men catch up. But experts said women tend to lead the way in issues related to health.
"Women are well-known to be the early adopters of health-related behaviors," Dietz said. "They also play a key role in most families in terms of what kinds of foods come into the house and how it is prepared."
Ogden noted that obesity rates vary by age, with adults ages 40 to 59 having the highest. About 40 percent of men in this age group are obese, compared with 28 percent of those 20 to 39 and 32 percent of men 60 and older. Among women, 41 percent of those 40 to 59 are obese, compared with 30.5 percent of women 20 to 39 and about 34 percent of women age 60 and older.
There are also large racial disparities among women. Approximately 53 percent of non-Hispanic black women and 51 percent of Mexican-American women ages 40 to 59 are obese, compared with about 39 percent of non-Hispanic white women of the same age.
Several researchers noted that childhood obesity rates are continuing to increase.
"As more obese children reach adulthood, it is conceivable that obesity levels will begin to rise again," David B. Allison, director of the clinical nutrition research center of the University of Alabama at Birmingham wrote in an e-mail.
In response, the federal government this week is announcing plans to expand efforts to combat obesity among young people, including $10 million to build new school playgrounds.
Here's a link to the report:http://www.cdc.gov/nchs/pressroom/07newsreleases/obesity.htm.