The obesity epidemic in America is getting worse, new federal data show.

As of 2015-2016, about four in 10 U.S. adults were obese, up from 37.7 percent during 2013-2014.

The news for children and teens isn’t much better. Overall, nearly 19 percent were obese in 2015-2016, up from about 17 percent during the previous two years.

The report, released Friday by the Centers for Disease Control and Prevention’s National Center for Health Statistics, shows a trend of increasing obesity among Americans over the past 18 years, with middle-aged adults and some minority women hit the hardest.

Obesity rates were highest for black and Hispanic women: 55 percent and 51 percent, respectively. By comparison, 38 percent of white women and 15 percent of Asian women were obese. By age, obesity in adults was most common among 40- to 59-year-olds — 43 percent — and least common among 20- to 39-year-olds — 36 percent.

“It is a serious concern because it’s a risk factor for many health conditions, such as diabetes, heart disease, stroke and even some kinds of cancer,” said Craig M. Hales, M.D., lead author of the report and a medical epidemiologist at the CDC.

“I hope that people think about their own health [and] do their own assessment in terms of where they are in terms of their weight,” Hales said.

Adults with a body mass index — a calculation derived from a person’s height and weight — of 30 or higher are considered obese. For kids, obesity is determined by whether a child’s BMI is at or above the 95th percentile on the CDC’s growth charts.

The continued uptick in obesity prevalence surprised Wendy L. Bennett, M.D., a cardiovascular disease researcher and primary care doctor at Johns Hopkins Bayview Medical Center in Baltimore. But she was most troubled by the high rates of obesity among black and Hispanic women.

“It’s very challenging [for many primary care doctors] to provide high-quality obesity management and nutrition services — especially for our low-income patients,” Bennett said.

The data confirm that federal, state and local health policymakers need to continue campaigns that promote good nutrition and exercise, but that greater efforts are needed for women, said Bennett, whose research focuses on obesity and women’s health.

For example, she said initiatives for pregnant women — many of whom struggle to lose added weight after giving birth — could help them establish healthy routines early in pregnancy. And campaigns promoting healthy lifestyles must reflect the cultural, racial and regional diversity among Americans, Bennett said.

“A one-size-fits-all program or one-size-fits-all policy we now know won’t work,” she said.

Among kids, the odds of being obese were lower in younger children. There were also differences based on race and ethnicity among 2- to 19-year-olds overall. Nearly 26 percent of Hispanic kids and 22 percent of black kids were obese, the report showed. On the other end of the spectrum, 11 percent of Asian-American kids and 14 percent of white kids were obese.

Eduardo Sanchez, M.D., chief medical officer for prevention at the American Heart Association, said that helping people eat healthier and move more comes down to the basics of supply and demand.

“It will take a massive push from the food and beverage industry to increase the supply of affordable, healthy, nutritious foods and fewer sugary drinks. And it takes a tremendous effort on the part of consumers to demand healthier products and policies in their communities. We all have to do our part,” he said.

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