Extreme obesity affecting more children at younger ages

Extreme obesity is affecting more children at younger ages, with 12 percent of black teenage girls, 11.2 percent of Hispanic teenage boys, 7.3 percent of boys and 5.5 percent of girls now classified as extremely obese, according to a Kaiser Permanente study of 710,949 children and teens that appears online in the Journal of Pediatrics.

This is the first study to provide a snapshot of the prevalence of extreme obesity in a contemporary cohort of children ages 2 - 19 years from a large racially and ethnically diverse population using the recent 2009 U.S. Centers for Disease Control and Prevention extreme obesity definition. Previous research was based on recent National Health and Nutrition Examination Survey (NHANES) data and included information on obesity but not extreme obesity.

"Children who are extremely obese may continue to be extremely obese as adults, and all the health problems associated with obesity are in these children's futures. Without major lifestyle changes, these kids face a 10 to 20 years shorter life span and will develop health problems in their twenties that we typically see in 40 - 60 year olds," said study lead author Corinna Koebnick, PhD, a research scientist at the Kaiser Permanente Southern California's Department of Research and Evaluation in Pasadena, Calif. "For example, children who are extremely obese are at higher risk for heart disease, type 2 diabetes, fatty liver disease and joint problems, just to name a few."

Researchers used measured height and weight in electronic health records to conduct a cross-sectional study of 710,949 children ages 2 - 19 years in the Kaiser Permanente Southern California integrated health plan in 2007 and 2008. Children in the study had an average of 2.6 medical visits per year where height and weight were measured.

The study found that 7.3 percent of boys and 5.5 percent of girls were extremely obese, translating into more than 45,000 extremely obese children in this cohort. The percentage of extreme obesity peaked at 10 years in boys and at 12 years in girls. The heaviest children were black teenage girls and Hispanic boys. The percentage of extreme obesity was lowest in Asian-Pacific Islanders and non-Hispanic white children.

According to the recent CDC recommendations, extreme obesity is defined as more than 1.2 times the 95th percentile, or a body mass index (BMI) of more than 35 kilograms/meter squared. Obesity is defined as more than the 95th percentile or a BMI of more than 30 kg/m2. Overweight is defined as more than the 85th percentile or a BMI of more than 25 kg/m2. The BMI is a reliable indicator of body fatness and calculated based on height and weight. For children, BMI percentiles are the most commonly used indicator to assess the size and growth patterns of individual children. The percentile indicates the relative position of the child's BMI number among children of the same sex and age.

"Our focus and concern is all about health and not about appearance. Children who are morbidly obese can do anything they want -- they can be judges, lawyers, doctors -- but the one thing they cannot be is healthy," said study co-author Amy Porter, MD, a Kaiser Permanente Baldwin Park pediatrician who leads the Pediatric Weight Management Initiative for Kaiser Permanente's Southern California Region.

"The most important advice to parents of extremely obese children is that this has to be addressed as a family issue. There is rarely one extremely obese kid in a house where everyone else is extremely healthy. It's important that everyone in the family is invested in achieving a healthier lifestyle," Porter said.

"This publication is only the beginning. Now we are trying to quantify the health risks and long-term effects associated with extreme obesity, determine which groups are affected most, and develop strategies for population care management to reduce these health risks. Children's health is important and we have a long way to go," Koebnick said.