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Obesity has grown into a major public health issue over the past several decades. Between 1980 and 2002, the prevalence of obesity in adults doubled and the prevalence of overweight children and adolescents tripled, with no significant change occurring since 2003–2004.1 The most recent data from the National Health and Nutrition Examination Survey (NHANES) 2011–2012 reveals that 69% of adults are overweight with 35% of these individuals meeting the criteria for obesity.2 Seventeen percent of children and adolescents in the United States are obese, with an additional 15% classified as overweight.3 Body mass index (BMI), defined as body weight (in kg) divided by height squared (in [meters]2), is the most commonly used indicator of overweight and obesity. Overweight is defined by a BMI between 25 and 29.9 kg/m2. Adults with a BMI equal to or greater than 30 kg/m2 are classified as obese, and those with a BMI equal to or greater than 40 kg/m2 as morbidly obese (Class III). Table 16-1 provides a chart that can be used to determine an adult’s BMI and weight classification based on height and body weight. Children are at risk of being overweight if their BMI falls between the 85th and 95th percentile for their age and sex on standard growth charts, and considered obese at or above the 95th percentile.

TABLE 16-1Adult BMI and Weight Classification Based on Height and Body Weight

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