Obesity rates are going up among American women, new study shows.

"Obesity remains a public health concern," Cynthia Ogden, author of the study and epidemiologist at the U.S. Centers for Disease Control and Prevention's (CDC) National Center for Health Statistics, said in a statement published in WebMD.

Two studies from CDC show that Americans seem to make little improvement in its battle against obesity.

According to the first study, 40 percent of women and 35 percent of men are obese. While obesity rates among women increased, rates among men remain steady.

America's 30-year-old obesity problem is still hanging strong, according to an editorial about the study. Obesity rates remain high despite millions spent for research, trials, observational studies, community and hospital programs, as well as the development of equipment and medication.

"Although it is impossible to know what the extent of the obesity epidemic would have been without these efforts, the data reported ... certainly do not suggest much success," wrote JAMA editors Dr. Jody Zylke and Dr. Howard Bauchner.

Dr. David Katz, director of the Yale-Griffin Prevention Research Center and president of the American College of Lifestyle Medicine, said that the American culture seems to "ignore" obesity and "denies it or simply profits from it."

In the study, Ogden and her team used weight and height statistics from a national health survey and looked at the trends among adults between 2005 and 2014. Data were collected from 2,800 women with an average age of 48, and 2,600 men with an average age of 47.

The results showed that prevalence of obesity among women went up, while prevalence among men remained the same.

According to the researchers, 38 percent of American adults are considered obese and nearly 8 percent are extremely obese, which includes 10 percent of women and 5.5 percent of men.

The researchers also found that smoking was not a factor in obesity among women. However, findings showed that women with more than a high school education were less likely to be obese.

A separate study was also done by the same team to determine obesity rates among young Americans. In the second study, findings show that 17 percent of children and adolescents are obese, and nearly 6 percent were extremely obese. Rates among young children are leveling off, but rates among teens slightly increased.

Both studies were published in the Journal of the American Medical Association.