About 5 percent of children and teens in the United States are now classified as \"severely obese,\" and the prevalence is increasing, according to a scientific report from the American Heart Association. Despite recent data suggesting that childhood obesity rates are starting to level off across the country, \"a worrisome trend has emerged in the form of severe pediatric obesity,\" researchers wrote in their paper published Monday in the journal Circulation. \"Severe obesity in young people has grave health consequences,\" lead author Aaron Kelly of the University of Minnesota Medical School said in a statement. \"It\'s a much more serious childhood disease than obesity.\" The researchers define children over age 2 as severely obese if they either have a body mass index (BMI) that\'s at least 20 percent higher than 95 percent of other children of the same age and gender, or a BMI score of 35 or higher. BMI is a measurement based on weight and height. Age- and gender-specific growth charts are used to calculate BMI for children. Children at the 95th BMI percentile or higher are obese, and those between the 85th and 95th percentiles are overweight. For example, a 7-year-old girl of average height weighing 75 pounds (34 kilograms), or a 13-year-old boy of average height weighing 160 pounds (73 kilograms), would be defined as severely obese. According to the researchers, severely obese children have higher rates of type 2 diabetes and cardiovascular issues at younger ages, including high blood pressure, high blood cholesterol and early signs of atherosclerosis, the disease process that clogs arteries. Treatment options for children with this level of obesity are limited, as most standard approaches to weight loss are insufficient for them, the researchers said. Most experts recommend a step-wise approach for treating severely obese children, with treatment getting gradually more intensive from lifestyle changes, to medication and potentially surgery. \"But the step from lifestyle change and medication to surgery is unacceptably large because weight loss surgery isn\'t appropriate for or available to all severely obese children,\" Kelly said, while calling for \"innovative approaches to fill the gap between lifestyle/medication and surgery.\" More research is needed on bariatric surgery\'s effects and safety, as well as effectiveness of lifestyle modification interventions, including adherence to dietary and physical activity plans, in treating children with severe obesity, the researchers said.