A new government research study shows that obesity is still rising among American adults, with women having overtaken men in the obese category, Portland Press Herald reports.

The rate of obesity has risen despite more than a decade of public-awareness campaigns in the U.S. and other efforts to get people to watch their weight.

"This is a striking finding" and suggests that a situation that was thought to be stable is getting worse, said Dr. William Dietz, an obesity expert at George Washington University.

The Centers for Disease Control and Prevention, the organization that conducted the study, said in a report Thursday that the obesity rate has climbed to nearly 38 percent of adults, up from 32 percent about a decade earlier. The obesity rate was higher for women, at 38 percent, compared with 34 percent for men.

The report was based primarily on a survey conducted in 2013-14.

Experts said they had could offer no explanation for the rising obesity rate.

In the recent years, the U.S. government has launched several anti-obesity campaigns to encourage people to eat better and exercise. New federal rules to remove trans fats from grocery and to require restaurants to post calorie counts have been adopted.

A CDC report last year had noted a decline in obesity among children ages 2 to 5. Their rate had fallen to about 8 percent in the 2011-12 survey, down from 14 per cent a decade earlier.

The CDC measures obesity by calculating Body Mass Index, a ratio of weight to height.