HEALTH NEWS

Study Title:

Childhood Obesity on the Rise

Study Abstract

Objective
To determine the extent to which the 2007 definitions for severe obesity (body mass index [BMI] ≥99th percentile for age and gender) and morbid obesity (BMI ≥40kg/m2) affects different groups of American children and adolescents and has increased over time.

Methods
Analysis of nationally representative data from the National Health and Nutrition Examination Survey (NHANES) II, III, and 1999–2004; 12 384 US children and adolescents ages 2 to 19 years were included in the analysis. Outcome measures were the proportion of subjects with severe and morbid obesity, with age, gender, race, and poverty-income ratio (PIR) as key variables.

Results
In 1999–2004, 3.8% of children 2 to 19 years old had a BMI in the ≥99th percentile, with higher prevalence among boys than girls (4.6% vs 2.9%; P < .001). Prevalence was highest among blacks, 5.7% and Mexican Americans, 5.2%, compared with whites, 3.1% (P < .001). The prevalence differed by the PIR category as well (4.3% for those with PIR ≤3 vs 2.5% for those with PIR>3; P=.002). BMI ≥40kg/m2 was found in 1.3% of adolescents ages 12 to 19 years, with similar associations with race and poverty. The overall prevalence of BMI ≥99th percentile has increased by more than 300% since NHANES II (1976), and over 70% since NHANES III (1994) in children 2 to 19 years of age.

Conclusions
Rates of severe childhood obesity have tripled in the last 25 years, with significant differences by race, gender, and poverty. This places demands on health care and community services, especially because the highest rates are among children who are frequently underserved by the health care system.

From press release:

Rates of severe childhood obesity have tripled in the last 25 years, putting many children at risk for diabetes and heart disease, according to a report in Academic Pediatrics by an obesity expert at Brenner Children's Hospital, part of Wake Forest University Baptist Medical Center.

"Children are not only becoming obese, but becoming severely obese, which impacts their overall health," said Joseph Skelton, M.D., lead author and director of the Brenner FIT (Families in Training) Program. "These findings reinforce the fact that medically-based programs to treat obesity are needed throughout the United States and insurance companies should be encouraged to cover this care."

The research was published online and will appear in the September print edition. Skelton and colleagues compared data from the National Health and Nutrition Examination Survey (NHANES). They looked at the prevalence of obesity and severe obesity in a study population of 12,384 children, representing approximately 71 million U.S. children ages 2 to 19 years.

Severe childhood obesity is a new classification for children and describes those with a body mass index (BMI) that is equal to or greater than the 99th percentile for age and gender. For example, a 10-year-old child with a BMI of 24 would be considered severely obese, Skelton said, whereas in an adult, that is considered a normal BMI. An expert committee convened by the American Medical Association, the Centers for Disease Control and the Department of Health and Human Services proposed the new classification in 2007.

The research by Skelton and colleagues is the first of its kind to use the new classification and detail the severity of the problem. They found that the prevalence of severe obesity tripled (from 0.8 percent to 3.8 percent) in the period from 1976-80 to 1999-2004. Based on the data, there are 2.7 million children in the U.S. who are considered severely obese.

Increases in severe obesity were highest among blacks and Mexican-Americans and among those below the poverty level. For example, the percentage of Mexican-American children in the severely obese category was 0.9 percent in 1976-80 and 5.2 percent in 1999-2004.

Researchers also looked at the impact of severe obesity and found that a third of children in the severely obese category were classified as having metabolic syndrome, a group of risk factors for heart attack, stroke and diabetes. These risk factors include higher-than normal blood pressure, cholesterol and insulin levels.

"These findings demonstrate the significant health risks facing this morbidly obese group," wrote the researchers in their report. "This places demands on health care and community services, especially because the highest rates are among children who are frequently underserved by the health care system."

Study Information

Joseph A. Skelton, Stephen R. Cook, Peggy Auinger, Jonathan D. Klein, Sarah E. Barlow
Prevalence and Trends of Severe Obesity Among US Children and Adolescents
Academic Pediatrics
2009 July
Department of Pediatrics, Wake Forest University School of Medicine, Winston-Salem, NC.