By LAURAN NEERGAARD, AP Medical Writer

WASHINGTON (AP) - New research shows childhood obesity affects more than self-esteem: It's making more youngsters sick enough to be hospitalized.

Obesity still accounts for a tiny proportion of all child hospitalizations. But the new research — among the first to show how much more is at stake than fat children simply growing into fat adults — found hospital costs related to childhood obesity more than tripling, reaching $127 million by 1999.

Doctors have long warned that childhood obesity has become epidemic. But parents in particular haven't understood that being overweight can seriously sicken youngsters now, not just when they're grown and start worrying about heart disease, said lead researcher Dr. William Dietz of the Centers for Disease Control and Prevention.

The new study "changes the perspective that obesity is simply a cosmetic problem to really focus on ... childhood obesity as a serious medical problem," he said.

The study was published Wednesday in the journal Pediatrics.

Obesity specialists called it high time someone pointed out the growing danger.

"The kids who are fat are getting really fatter," said Dr. Nazrat Mirza of Children's National Medical Center, who has patients as young as 5 with obesity-caused sleep apnea.

The study "represents just the tip of the iceberg," she said — because doctors often don't record obesity on hospital discharge records, so the CDC probably missed many cases. Insurance companies don't pay to treat it until the child comes down with a formal illness, Mirza complained.

About 13 percent of children and adolescents are overweight or obese, more than double the number two decades ago. Experts blame TV, computer games, lack of safe playgrounds and other factors that encourage kids to be sedentary — plus more access to super-sized portions of high-calorie foods.

More children are suffering Type 2 diabetes, a dangerous disease that once struck mostly in middle age. Obesity also can worsen asthma and spark gallbladder disease. People can die from obesity-caused sleep apnea, Dietz said, when fat in the back of the throat combines with large tonsils to block the airway.

CDC researchers culled hospital discharge records, comparing obesity-related hospitalizations of 6- to 17-year-olds between 1979 and 1981 with those from 1997 through 1999.

Diabetes diagnoses nearly doubled, accounting for 2.36 percent of child hospitalizations in the late 1990s vs. 1.43 percent in the late 1970s.

Diagnoses of obesity alone tripled to reach 1 percent of hospitalizations.

Other obesity-related hospitalizations were more rare but rising rapidly — sleep apnea rose fivefold and gallbladder disease tripled. Asthma cases complicated by obesity rose 40 percent.

Olympic gold medal-winning gymnast Dominique Dawes and tennis great Martina Navratilova helped the government publicize the study Wednesday, racing through an obstacle course with youngsters in Washington to show them that staying fit is fun.

Give up the video games, Navratilova advised: "You're not going to become Michael Jordan by playing Space Invaders."

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