Fact Sheet : Child and Adolescent Obesity
Obesity refers to an excess proportion of total body fat. Body mass index (BMI) is the most common method to assess for obesity and is calculated by comparing weight to height. In children and adolescents weight status is determined using age- and sex-specific percentiles for BMI. Children with a BMI above the 95th percentile for age and sex are classified as obese, while those between the 85th and 95th percentile are classified as overweight. Childhood obesity can be brought on by a range of factors that often act in combination, but it is most directly related to an imbalance in caloric intake and energy expenditure.
Prevalence and Course
Over the past two decades, the prevalence of children who are obese has doubled, while the number of adolescents who are obese has tripled. Currently, approximately 17 percent of youth 2-19 years of age are obese, while 31.8 percent are overweight or obese. Children and adolescents who are obese are more likely to be overweight or obese in adulthood relative to their nonoverweight peers. Children whose parents are overweight or obese also are at higher risk for becoming obese.
Health and Psychosocial Consequences
Children who are obese are at greater risk for a number of adverse health conditions and outcomes including type 2 diabetes, non-fatty liver disease, asthma, sleep apnea, orthopedic problems, as well as cardiovascular risk factors such as hypertension, dyslipidemia and abnormalities in coronary arteries. Obese children have poorer quality of life than their nonobese peers and also are at increased risk for psychosocial problems such as poor self-esteem or peer victimization.
In addition to height and weight, areas of assessment relevant for obese children and adolescents include metabolic functioning, dietary intake, physical activity and sedentary activity. Assessing child and parent ability and motivation to implement changes to lifestyle behaviors is important to develop appropriate and targeted intervention plans. Social and emotional functioning should also be evaluated in obese children to screen for psychosocial difficulties. See the Expert Committee guidelines for detailed recommendations on the assessment of medical and behavior risk factors associated with pediatric obesity.
Developmental and Demographic Factors
The prevalence of obesity increases with age so the highest rates of obesity are seen in adolescents. African American and Hispanic youth have a higher prevalence of obesity relative to their Caucasian peers. In addition, youth from economically disadvantaged backgrounds, as well as youth from rural and inner-city settings, are at greater risk for obesity than their peers.
Meta-analytic and systematic reviews suggest there is adequate evidence that multi-component, moderate- to high-intensity behavioral interventions for obese youth ages 6 years and older can effectively yield short-term (up to 12 months) improvements in weight status. Including parents as agents of change is an important part of treatment for preadolescent children, while education and guidance in the use of behavioral strategies is instrumental to the successful treatment of obesity for youth of all ages. It is important to note, however, that most treatment studies in this area include fairly homogenous samples, with relatively little racial, ethnic and economic diversity.
Barlow, S.E., Expert Committee (2007). Expert committee recommendations regarding the prevention, assessment, and treatment of child and adolescent overweight and obesity: summary report. Pediatrics, 120, s164-192.
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Ogden, C.L., Carroll, M.D., Kit, B.K., & Flegal, K.M. (2012). Prevalence of obesity and trends in body mass index among US children and adolescents, 1999-2010. Journal of the American Medical Association, 307, 483-490.
Whitlock, E.P., O’Connor, E.A., Williams, S.B., Beil, T.L., & Lutz, K.W. (2010). Effectiveness of weight management interventions in children: A targeted systematic review for the USPSTF. Pediatrics, 125, e396-418.