Adults consider obesity the number one threat to children's health in the United States and many believe the problem is getting worse, according to a new poll.

Almost 40 percent of adults cited obesity was the biggest threat to youngsters and teenagers, followed by drug abuse, smoking, Internet safety and stress.

"The message about the dangers of obesity and the prevalence of the disease among children has really gotten through to the American public," said Dr. Matthew M. Davis, director of the University of Michigan C.S. Mott Children's Hospital National Poll.

"If we'd done this poll four years ago, obesity would not have been at the top of the list," he said.

Obesity rates among children and teens in the United States skyrocketed in the last 30 years. A 2008 study by the Centers for Disease Control in Atlanta showed nearly one in five children aged six to 11 and 18.1 percent of 12 to 19 year olds were obese.

More surprising, Davis said, is the rise of stress as a prominent health concern for parents, which he attributes to a trickle-down effect as the economy wobbles, parents react and children feel the changes.

"Current economic conditions affect kids too," he said. "Kids notice changes in family activities, patterns, gifts, sometimes something as basic as food," he said. "This has really resonated around the county."

Adults of different races and ethnicity rated the top three threats to children differently. Whites put obesity first, followed by drug abuse and smoking. For Hispanics drug abuse came first, obesity second and smoking third. Smoking was the main concern among blacks, followed by teen pregnancy and obesity.

The survey, conducted by polling company Knowledge Networks, Inc. for the university, surveyed 2,064 adults.

Davis said all the threats to children's health are behavioral, rather than congenital. Bullying, teen pregnancy, abuse and neglect, alcohol, and not enough opportunities for physical activity rounded out the top 10 health concerns.

Sixteen percent of adults cited sexting as the top threat.

"It's about children's behavior, parents behavior, community behavior. Parents say their communities don't have enough opportunities for physical activity. But that's not the kids' fault. It's because we build neighborhoods without sidewalks, without enough playgrounds and green spaces," Davis said.