Fattening may be flattening out, new data shows

After 25 years of expanding waistlines, American adults might have turned the corner in the battle of the bulge, according to federal data released Wednesday.

The Centers for Disease Control and Prevention (CDC) said 34.3 percent of adults — or more than 72 million people — were obese in 2005 and 2006. The figures were essentially unchanged from the previous two-year period for the first time since 1980.

The obesity rate remains slightly higher among women, at 35.3 percent, but that has stabilized since 1999, said Cynthia Ogden, the CDC epidemiologist who led the study. The rate for men was slightly lower at 33.3 percent, but it is not clear whether they also have reached a plateau, she said.

Obesity is defined as having a body mass index — a ratio of weight and height — of 30 or more. A woman who is 5 feet tall would be considered obese if she weighed at least 153 pounds. A 6-foot-tall man would be obese if his weight topped 221 pounds.

People who are obese are more likely to have diabetes, cardiovascular disease, high blood pressure and some types of cancer. Obesity is also associated with an increased risk of overall disability and of death from any cause. The more one weighs, the higher the risk.

More data are needed to determine whether the obesity epidemic has stalled or the new figures represent a temporary lull, Ogden and others said.

Some groups continue to struggle with their weight, according to data compiled for the CDC's National Health and Nutrition Examination Survey, which combines interviews with physical examinations.

Middle-age adults are still packing on the most pounds. The study found that 53 percent of non-Hispanic black women and 51 percent of Mexican-American women between 40 and 59 were classified as obese, compared with 39 percent of non-Hispanic white women.

After age 60, the obesity rate for black women jumped to 61 percent, though it declined to 37 percent for Mexican-American women and to 32 percent for non-Hispanic white women, according to the report.

Among men, obesity rates also were highest for those in their 40s and 50s, the study found. However, unlike for women, the researchers did not find significant differences among racial and ethnic groups. The researchers don't know why, Ogden said.

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 Allison, director of the clinical nutrition research center of the University of Alabama in Birmingham, wrote in an e-mail.

In recognition of the problem, the federal government is announcing plans this week to expand efforts to combat obesity among young people, including $10 million to build new school playgrounds.

Material from The Washington Post is included in this report.