From Medscape Medical News
Nancy Fowler Larson
March 18, 2010 — More than 7% of American boys and 5% of American girls are extremely obese, according to a study published online March 18 in the Journal of Pediatrics.
"The American Medical Association and the Centers for Disease Control and Prevention...recommendations on prevention, assessment, and treatment of childhood obesity are based on relatively limited knowledge about extreme childhood obesity at the population level," write Corinna Koebnick, PhD, research scientist, Kaiser Permanente Southern California's Department of Research and Evaluation, Pasadena, and colleagues. "Newer data on recent trends are not available. The present economic burden and health consequences are largely unknown and ill defined."
Reliable figures do exist for nationwide childhood obesity, which affects 17.1% of boys and 15.5% of girls. To determine the scope of extreme obesity in a multicultural, racially diverse population, the research team conducted a cross-sectional study in of 710,949 children aged 2 through 19 years. Approximately half were Hispanic. All were enrolled between 2007 and 2008 in a managed healthcare system that recorded information about height and weight, using electronic health records.
The researchers employed Centers for Disease Control and Prevention definitions for obesity and overweight, which include:
Extreme obesity: weight more than 1.2 times the 95th percentile, or body mass index BMI) greater than or equal to 35 kg/m2
Obesity: weight higher than the 95th percentile, or BMI of 30 kg/m2 or more
Overweight: weight above the 85th percentile, or BMI of 25 kg/m2 or more
Among other findings, the study authors discovered that more boys are extremely obese than girls, and that the condition varies between sexes and among ethnic groups, as follows:
7.3% of boys and 5.5% of girls were extremely obese
Extreme obesity peaked at 10 years of age in boys and at age 12 years in girls, who also demonstrated a second peak at ages 18 years (P value for sex × age interaction = .036); rates of extreme obesity are similar for boys and girls after age 18 years
Hispanic boys (as many as 11.2%) and black girls (up to 11.9%) were the heaviest of all children
The percentage of extreme obesity was lowest in Asian-Pacific Islanders (2.2%) and non-Hispanic white children (3.3)
Extremely obese children are at risk for conditions including heart disease, type 2 diabetes, fatty liver disease, and joint problems decades before those of normal weight
"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," Dr. Koebnick said in a press release.
"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."
Subsequent studies will explore the future implications of extreme obesity and its treatment.
J Pediatr. Published online March 18, 2010.