Teen Weight Gain Surpasses Previous Generation

And the fatter the kids, the less physically fit they are

FRIDAY, March 5, 2004 (HealthDayNews) -- Teens are gaining weight at twice the rate their parents did when they were in adolescence.

And the fatter teens get, the quicker they are to tire when exercising.

Those are the findings of two studies presented March 5 at the American Heart Association's Annual Conference on Cardiovascular Disease, Epidemiology and Prevention in San Francisco.

Both studies, the authors say, point to the need for children to maintain a healthy weight so they can stay physically active and reduce their risk of early cardiovascular problems.

About 15 percent of U.S. teens and children are now overweight, according to the U.S. Centers for Disease Control and Prevention, and that number has more than doubled since the early 1970s.

For the first study, University of Iowa researchers compared two generations in a long-running research project called the Muscatine study that began in Iowa in 1971. The researchers compared the body mass indexes (BMIs) of 518 parents when they were aged 15 to 18 with the BMIs of 228 of their children during the same teenage years.

While the parents' BMIs increased by 0.44 per year from the ages of 15 to 18, their children's BMIs rose by 1.1 per year -- more than twice as much.

"I think it's concerning that there is such an increase," says study leader Dr. Patricia H. Davis, an associate professor of neurology at the University of Iowa. The team also found risk factors for heart disease such as high blood pressure were strongly related to weight, with problems more common as weight increased.

Among males, the average BMIs of the parents when they were teens was 22.97; for their sons it was 24.24, Davis says. Among females, the average BMIs of the parents as teens was 21.9; for their daughters it was 24.4.

A BMI of 18.5 to 24.9 is considered normal weight. While the average BMIs of the current teens aren't classified as overweight, they're very close to being considered heavy.

In the second study, researchers found excess weight hampers a child's ability to be physically active, and that can set him or her up for a vicious cycle of inactivity and even more weight gain.

In the study of 525 boys and girls, aged 4 to 18, Dr. Maria Serratto of the University of Illinois at Chicago Medical Center and JHS Hospital of Cook County, tested the children's endurance on a treadmill as they walked at various speeds and inclines.

They could leave the treadmill when they got too tired to continue. "There was a significant difference in endurance time between the obese and non-obese," says Serratto. "For [overweight] boys, it was 2 minutes or less [total treadmill time]; for the girls, 1.5 minutes."

The heavy children, she says, became physically exhausted much sooner than the normal-weight children did.

Another expert says both studies confirm what's been known about childhood weight problems and inactivity, and should serve as a call to action for parents, teachers and others concerned about the health of America's youth.

"This trend of doubling the rate of weight gain within just a 20-year time frame is really quite scary for the future health and productivity of the nation," says Lona Sandon. She is a registered dietitian and researcher at the University of Texas Southwestern Medical Center in Dallas and a spokeswoman for the American Dietetic Association.

While parents, teachers, school administrators and others all need to promote healthy eating and activity habits, Sandon says parents may be the best place to start.

Sandon urges them to serve as good role models for their children when it comes to a healthful diet and proper exercise.

More information

To learn how to help children get more exercise, visit the U.S. Centers for Disease Control and Prevention. For information on weight problems in children, check with the American Academy of Pediatrics.

SOURCES: Patricia H. Davis, M.D., associate professor, neurology, University of Iowa, Iowa City; Maria Serratto, M.D., director, pediatric exercise lab, University of Illinois at Chicago Medical Center and the JHS Hospital of Cook County, and professor, pediatric cardiology, University of Illinois at Chicago; Lona Sandon, R.D., registered dietitian, assistant professor, University of Texas Southwestern Medical Center, Dallas; March 5, 2004, presentations, American Heart Association Annual Conference on Cardiovascular Disease, Epidemiology and Prevention, San Francisco
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