NEW YORK (Reuters Health) - The U.S. might be missing an opportunity to rein-in bulging waistlines, according to a new report that shows many obese teens put on extra weight as they grow up.
In a nationally representative study of American youth, researchers found that nearly one in 12 teenagers became severely obese as they entered adulthood — landing them some 100 pounds above their ideal weight.
And of those who were obese to begin with, about half the girls and more than a third of the boys grew into the larger-size category, raising their odds of developing heart disease, diabetes and certain types of cancers.
“People with severe obesity suffer from potentially life-threatening problems,” said Penny Gordon-Larsen, a nutrition scientist at the University of North Carolina at Chapel Hill, who led the research.
“The prevention efforts that we’ve had in the past maybe have not been as successful as we would have liked them to be,” she added. “We really need to prevent kids from becoming obese teenagers, and then prevent those teenagers from becoming severely obese adults.”
According to the Centers for Disease Control and Prevention, medical expenses related to overweight and obesity eat up about nine percent of total U.S. medical expenditures, amounting to $147 billion in 2008.
In the meantime, the national waistline is only getting larger. Several states now have obesity rates of more than 30 percent, with Mississippi leading the pack at 34.4 percent of residents. Colorado, with the leanest population in the nation, still has an obesity rate of 18.6 percent.
Gordon-Larsen said weight-loss drugs — even combined with diet and lifestyle changes — are not very effective and have side effects. Surgery, such as gastric bypass or banding, lets people shed more pounds, but comes with a big price tag and potential complications.
“Prevention is easier, because obesity is hard to treat,” Gordon-Larsen said in a telephone interview.
The study tapped into data from the National Longitudinal Study of Adolescent Health, which has followed thousands of kids from middle schools and high schools since the mid-1990s. It is the first to track how obese teenagers’ weight changes as they grow up.
At the outset, one percent of the youngsters were severely obese, defined as having a body mass index, or BMI, of 40 or more. For an average adult, that can easily mean 100 or more superfluous pounds.
BMI, a means of estimating body fat, is calculated by dividing weight in kilos by height in meters squared. Overweight is generally defined as a BMI between 25 and 30, obesity between 30 and 40.
Over 13 years, eight percent of the now adults landed in the severe obesity category — and the heavier they were to begin with, the higher their chances of doing so, not surprisingly.
Obese black girls had the highest risk of becoming severely obese later on.
And those extra pounds can have a big impact on health, Dr. Louis Aronne, an obesity expert at Weill-Cornell Medical College in New York, told Reuters Health by e-mail.
For instance, scientists have estimated that a 20-year-old white man with a BMI greater than 45 will lose 13 years of life due to obesity-related disease. A woman’s lifespan would be shortened by eight years.
Writing in the Journal of the American Medical Association, the researchers suggest that these girls should be the number one target for obesity prevention efforts.
Gordon-Larsen said new interventions to curb obesity were needed across the board, from pregnant women to school kids and neighborhood campaigns.
SOURCE: link.reuters.com/naf64q JAMA/Journal of the American Medical Association, November 9, 2010.