It's been two decades since federal health officials said the U.S. was experiencing a " growing obesity epidemic " that was putting millions of lives at stake – but the situation has gotten significantly worse since 1999.

At the turn of the century, 30.5% of American adults were obese, meaning they had a body mass index of 30 or higher. That rate largely increased through 2015-2016, helping to fuel related health issues like diabetes , cardiovascular disease and some cancers – all of which are among the leading causes of death in the U.S.

According to data released Thursday by the Centers for Disease Control and Prevention, the obesity rate reached 42.4% in 2017-2018 – surpassing 40% for the first time. Although the increase was not significant between 2015-2016 and 2017-2018, the new data represents a failure to meet the federal government's public health goals set for this year.

"In the United States, the prevalence of obesity among adults has moved further away from the Healthy People 2020 goal of 30.5%," the report from the CDC's National Center for Health Statistics says.

While adults across age groups saw similar obesity rates in 2017-2018, there were disparities by race and ethnicity: At 49.6%, the obesity rate was highest among black adults, though it was also above 40% for Hispanics and non-Hispanic white adults. The obesity rate was lowest among Asians, at 17.4%.

Other research shows there are differences by socioeconomic status and region. In 2018, for example, adult obesity prevalence was highest in Mississippi and West Virginia and lowest in Colorado, according to survey data.

"Beyond getting fit and eating healthy, we also must address income, education and access to health care,” Mark Schoeberl, executive vice president for advocacy at the American Heart Association, says in an email.

The new data shows that the share of adults who were severely obese – with a BMI of 40 or higher – also has risen since 1999-2000, nearly doubling from 4.7% to 9.2%. And while men and women saw similar obesity rates, women were significantly more likely to be severely obese than men. People who are severely obese are at even higher risk of issues like coronary heart disease and end-stage renal disease, the CDC report says.