New statistics cited in two papers report only a slight uptick in obesity rates since 2005. The statistics from the Centers for Disease Control and Prevention showed that more than 35 percent of U.S. adults (78 million people) are obese, defined as having a body mass index of 30 or greater. That is similar to the 2005-06 rate. An additional third of adults are overweight, the analysis found, also similar to the rates in 2005-06.

Likewise, data in children and teenagers from birth to age 19 reflect little change from the survey's 2007-08 data, according to the reports, which were published online Tuesday in the Journal of the American Medical Association. Almost 17 percent are obese and 32 percent are overweight or obese.

But though obesity rates may be flattening overall, increases and disparities can still be found in specific racial and ethnic groups.

Rates have risen to 58.5 percent among non-Hispanic black women and to nearly 45 percent among Mexican American women since 2004, for example. And among children and teens, about 21 percent of Hispanics and 24 percent of blacks are obese compared with 14 percent of non-Hispanic whites.

The report also found that gender differences appear to be fading, with percentages of overweight males catching up with or even overtaking those of females.

Among males under 19, obesity rose from 14 percent in 1999-2000 to 18.6 percent in the latest survey; in adult men, the rate jumped from 27.5 percent to 35.5 percent.

In addition, more adult men are now overweight or obese as compared with women �€�€� 73.9 percent to 63.7 percent. Severe obesity remains more common in women, however.

The apparent stabilizing rates follows 30-year expansion period but researchers noted little improvement among groups. Early in the decade, slight increases were seen among white, black and Hispanic men, and among Hispanic and black women. These changes may be leveling off, but the authors said they “found no indication that the prevalence of obesity is declining in any group.”

The new studies reflect 2009-10 data, the most recent available, from the government's National Health and Nutrition Examination Survey, which examined 6,000 adults and 4,111 children, measuring their body mass index, among other items.  The results were released online in the Journal of the American Medical Association.