Obesity rates may no longer be rising, but for the most severely overweight children and teens the news is not so good: they are getting heavier, faster.

About five percent of U.S. children and teens can be classified as "severely obese. " This new category of childhood obesity is the subject of a special statement the American Heart Association (AHA) issued recently.

“I am personally not surprised by the fact that five percent of children and teens are severely obese,” Aaron Kelly, lead author, told TheDoctor . Even though overall rates of childhood obesity are starting to level off, he explained, rates of severe obesity are on the rise.

According to the AHA, a 7-year-old girl of normal height who weighs 75 pounds, or a 13-year-old boy of average height who weighs 160 pounds would be defined as severely obese.

Because being overweight and obese are linked to health problems such as diabetes and heart disease, the increasing numbers of severely overweight children is a cause for concern. The hearts of children who are severely obese resemble those of middle aged adults.

“…[S]evere obesity in childhood is a much more serious disease than obesity and overweight," said Kelly, an associate professor of pediatrics at the University of Minnesota Amplatz Children’s Hospital.

Kids at the 95th Percentile

Children are severely obese if they either have a body mass index (BMI) that's at least 20 percent higher than the 95th percentile for their gender and age, or an absolute BMI score of 35 or higher and are over age 2, according to the statement's guidelines. Children at the 95th BMI percentile or higher are considered obese, and those between the 85th and 95th percentiles are classified as overweight.

For example, according to the AHA, a 7-year-old girl of normal height who weighs 75 pounds, or a 13-year-old boy of average height who weighs 160 pounds would be defined as severely obese.

So why are overall rates of childhood overweight and obesity leveling off while rates of severe obesity are on the rise? “I think that there are probably multiple factors that play into this,” Kelly said.

Diet and physical activity — the lack of it — play big roles, but a genetic predisposition is also relevant, as are other factors such as socioeconomic status. “We know that severe obesity tends to be more prevalent in children from families that have lower income,” said Kelly.

Parents are also an issue. Some are in denial about their children's weight problem, thinking they will outgrow it. Many are unsure of what to do. Many experts are also uncertain.

“We really need more research to better understand what is happening, so we can prevent kids who are overweight or obese from transitioning into this higher risk category,” Kelly said.

The American Heart Association statement emphasizes the need for funding and research to determine what approaches help kids most. What sorts of lifestyle modifications, such as diet and exercise are most effective? How safe are weight loss drugs and bariatric surgery for children and adolescents? Lifestyle modification works fairly well in children who are overweight or obese, Kelly said. However, evidence suggests this approach is not effective in severely obese children.

Ways to Get the Weight Off

“We need novel approaches to lifestyle modification because the traditional approach does not work really well in the severely obese pediatric population,” said Kelly. Very low calorie diets, meal replacement, and perhaps more intense dietary counseling and physical activity counseling are among the approaches used to help severely obese children lose weight before it permanently — and negatively — affects their health.

The safety and effectiveness of weight loss medications prescribed for kids is another area needing research. “ We need weight loss medications that are approved for use in adults to be tested in children and adolescents,” said Kelly. Only one weight loss medication is currently FDA-approved for teens, orlistat (brand name: Xenical). Kelly noted that this drug does not work very well and has side effects.

Very low calorie diets, meal replacement, and perhaps more intense dietary counseling and physical activity counseling are among the approaches used to help severely obese children lose weight before it permanently — and negatively — affects their health.

In the end, a pill is not likely to be the answer, nor is advice, however well-informed and well-meaning. “Many of the teens who are severely obese are going to need more than lifestyle counseling to help them get healthy,” Kelly said.

Early evidence suggests weight loss or bariatric surgery is very effective in reducing BMI in teens, but the surgery is not currently widely available or typically used in severely obese teens, and is not often covered by insurance. There are also risks associated with the surgery, especially since many bariatric procedures are irreversible, Kelly said. “So we need more long-term studies on the safety and effectiveness of bariatric surgery”.

The report, published online in the journal Circulation, is designed to raise awareness and serve as a call to action.

The first step is to identify the problem and realize that the weight is not going to go away by itself. It is only when parents and pediatricians acknowledge that a child has a serious weight problem that they can start to take steps to help.

Parents of seriously overweight and obese children may want to get advice on how to raise this psychologically loaded issue sensitively. But they can rest assured that helping their children lose weight is one of the greatest health gifts they can give them.