High BMI remains steady in U.S. children, adolescents

The prevalence of high BMI among children and teens in the United States ranges from about 10% for infants and toddlers to 18% for adolescents and teens. These rates appear to have remained relatively stable over the past 10 years, except for an increase for boys aged 6 to 19 years who are at the very heaviest weight levels, according to new data.

Researchers at the CDC used 2007-2008 National Health and Nutrition Examination Survey (NHANES) data to determine the most recent estimates of high BMI among children and adolescents aged 2 to 19 and high weight for recumbent length among infants and toddlers from birth to age 2.

The analysis included height and weight assessment of 3,281 children and adolescents and 719 infants and toddlers. Children were ≥95th percentile of weight for recumbent length and at one of three levels of high BMI: ≥97th, ≥95th or ≥85th percentile.

For infants and toddlers, 9.5% were ≥95th percentile of the weight-for-recumbent-length CDC growth charts (95% CI, 7.3-11.7).

For children and adolescents, 11.9% were ≥97th percentile (95% CI, 9.8-13.9), 16.9% were ≥95th percentile (95% CI, 14.1-19.6) and 31.7% were ≥85th percentile of BMI for age (95% CI, 29.2-34.1).

Further categorized by different age groups, 10.4% of children aged 2 to 5, 19.6% of children aged 6 to 11 and 18.1% of adolescents aged 12 to 19 were ≥95th percentile of BMI for age.

“Based on the adult definition of obesity (BMI >30) in 2007-2008, 12.6% of adolescents aged 12 through 19 years were obese,” the researchers wrote.

Although the researchers did not identify a significant trend in high weight for length or BMI during 1999-2000 and 2007-2008, they reported a significant trend in high weight for boys aged 6 to 19 who were at the highest BMI cut-point and among non-Hispanic white boys of the same age.

Despite efforts to prevent childhood obesity, “the results presented here indicate that the prevalence of high BMI in childhood has remained steady for 10 years and has not declined. Moreover, the heaviest boys may be getting even heavier,” the researchers wrote.

“More research is needed to identify the behavioral, biological and environmental factors sustaining these levels of high BMI in U.S. children,” they concluded.

Ogden CL. JAMA. 2010;303:242-249.