The current epidemic of inactivity and the associated epidemic of obesity are being driven by multiple factors (societal, technologic, industrial, commercial, financial) and must be addressed likewise on several fronts. Foremost among these are the expansion of school physical education, dissuading children from pursuing sedentary activities, providing suitable role models for physical activity, and making activity-promoting changes in the environment. This statement outlines ways that pediatric health care providers and public health officials can encourage, monitor, and advocate for increased physical activity for children and teenagers.
INTRODUCTION
IN 1997, THE World Health Organization declared obesity a global epidemic with major health implications. 1 According to the 1999 -2000 National Health and Nutrition Examination Survey (www.cdc.gov/nchs/nhanes.htm), the prevalence of overweight or obesity in children and youth in the United States is over 15%, a value that has tripled since the 1960s. 2 The health implications of this epidemic are profound. Insulin resistance, type 2 diabetes mellitus, hypertension, obstructive sleep apnea, nonalcoholic steatohepatitis, poor self-esteem, and a lower health-related quality of life are among the comorbidities seen more commonly in affected children and youth than in their unaffected counterparts. [3][4][5][6][7] In addition, up to 80% of obese youth continue this trend into adulthood. 8,9 Adult obesity is associated with higher rates of hypertension, dyslipidemia, and insulin resistance, which are risk factors for coronary artery disease, the leading cause of death in North America. 10
Assessment of OverweightIdeally, methods of measuring body fat should be accurate, inexpensive, and easy to use; have small measurement error; and be well documented with published reference values. Direct measures of body composition, such as underwater weighing, magnetic resonance imaging, computed axial tomography, and dual-energy radiograph absorptiometry, provide an estimate of total body fat mass. These techniques, however, are used mainly in tertiary care centers for research purposes. Anthropometric measures of relative fatness may be inexpensive and easy to use but rely on the skill of the measurer, and their relative accuracy must be validated against a "gold-standard" measure of adiposity. Such indirect methods of www.pediatrics.org/cgi