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The growing epidemic of childhood overweight and obesity poses serious health concerns to our nation as well as to countries around the world. Since 1980, the figures on these conditions have more than tripled; in the United States from 2011 to 2012, 16.9% of children and adolescents aged 2 through 19 years were obese and 31.8% were either overweight or obese.1,2
It is expected that 70% of adolescents who are obese will become overweight or obese adults, and this figure rises to 80% if one or both parents are obese.3,4 These children are at risk for the development of conditions once thought to be diseases of adulthood: cardiovascular disease, diabetes, insulin resistance, fatty liver, high cholesterol, hypertension, and sleep apnea.5 The effects of childhood obesity reach far beyond physical health. Studies demonstrate a link between obesity and mental health issues; academic performance and psychological function have been observed to be poorer and rates of absenteeism higher in overweight and obese children than in their normal-weight counterparts.6
In 2007, Expert Committee recommendations (ECRs) were released that included a universal assessment of body mass index (BMI) at every well-child visit or at least yearly starting at age 2.5 In 2011, the Institute of Medicine published a report highlighting the consensus of the Centers for Disease Control and Prevention (CDC) and the American Association of Pediatrics (AAP) that BMI should be calculated at every well-child visit.7 Healthy People 2020, a collection of science-based nationwide health improvement goals, includes reduction of childhood obesity as a leading health indicator (LHI).8 The LHIs, a subset of high-priority goals, include the following goal: “Reduce the proportion of children and adolescents age 2–19 who are considered obese from 16.9% to 14.5%.”8 The U.S. Preventive Services Task Force (USPSTF) recommends an annual BMI assessment for all children aged 6 years and older.9 Although the USPSTF recommendation differs from that of the Expert Committee in regard to age at initiation of screening (6 vs 2 years), the inclusion of a yearly BMI assessment in both recommendations underscores its importance in screening for overweight and obesity. Nonetheless, overweight and obesity in children are underdiagnosed with respect to the current recommendations.10-15 If practitioners fail to diagnose overweight and obesity in children consistently, appropriate prevention and treatment cannot be initiated.
As this epidemic continues to proliferate, primary care providers, specifically nurse practitioners and physician assistants, are in a pivotal position to make a difference. This article explores what can be done during office visits to help children avoid overweight and obesity, and ultimately the negative outcomes associated with these conditions; it discusses (1) the history and use of BMI as a diagnostic tool, especially in children; (2) current research findings and various intervention methods supported by the literature; and (3) the 2007 ECRs. To help practitioners put the latest research-based interventions and recommendations into use, a provider toolkit is included.
Body mass index
BMI is a measurement based on a person’s height (in meters) and weight (in kilograms). It is calculated as body weight (in kilograms) divided by the square of body height (in meters). Obtaining a patient’s BMI during an office visit is inexpensive, quick, and easy. The BMI provides an indirect measurement of body fatness, and its correlation with other anthropomorphic measurements, such as those obtained with dual-energy X-ray absorptiometry and underwater weighing, has been validated.16,17 Comparing the BMI with national reference data is the best possible method to define and identify overweight and obesity in children and adolescents.18
It is essential to rely on standardized methods, such as BMI, to identify overweight/obesity because informal methods such as visualization are often unreliable. A recent systematic review demonstrated that many parents of overweight and obese children and adolescents do not recognize them as such.19 To compound this issue, even highly trained healthcare professionals underrecognize overweight and obesity when relying on subjective, informal assessments.20,21 In one study, 80 healthcare providers were asked to categorize 33 children varying in body habitus as underweight, normal weight, overweight, or obese on the basis of their pictures. The healthcare providers correctly identified only 40% of the children as overweight or obese, although 60% actually met the criteria for above-normal weight when BMI was used.20 This finding demonstrates that subjective assessments are not adequate to identify children who require a diagnosis and possible intervention.
With BMI proven as a reliable indicator of body fatness, the CDC and AAP recommend yearly BMI screening for overweight or obesity starting at the age of 2 years.16 A systematic review of 96 articles in 2013 found consistent evidence to support the use of annual BMI screening as an important tool for the primary care provider to address childhood overweight and obesity.22
In adults, BMI values use set cutoff points, or threshold values, that are familiar to most clinicians. For instance, a BMI above 25 kg/m2 is considered overweight, and a BMI above 30 kg/m2 represents obesity. However, the amount of body fat in children changes according to age and gender. Consequently, BMI measurements for children and adolescents are interpreted with percentiles based on growth charts derived from population statistics.16 When considering the use of BMI screening for overweight and obesity in children and adolescents, practitioners need to be familiar with the use of percentiles from BMI charts to draw appropriate conclusions about risk categories (ie, underweight, normal weight, overweight, and obese.) The most current growth charts were last updated in 2000 and are available on the CDC website.23 An example is shown in Figure 1.
To use these charts correctly, providers must have the child’s age and calculate the BMI; for the BMI, height in inches and weight in kilograms are also needed. Automatic BMI calculators are often included in electronic medical records. When BMI percentile categories are determined, (1) the appropriate growth chart must be used, (2) age is plotted on the x-axis, and (3) BMI (kg/m2) is plotted on the y-axis. The intersection will correlate with the BMI percentile ranges distributed across the growth chart (Figure 1). Providers should have on hand available tools and technology, such as BMI calculators, current growth charts, and/or electronic medical record–facilitated BMI tracking tools to simplify calculation and increase compliance (Table).