CHILD AND ADOLESCENT OBESITY

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CHILD AND ADOLESCENT ­OBESITY Lawrence D. Hammer and Thomas N. Robinson

Vignette T. R. presented to the pediatric weight clinic at 16 years of age with a weight of 169 kg and a body mass index (BMI) of 60 kg/m2. Her mother had an unremarkable pregnancy, labor, and delivery, with the exception of gestational diabetes. T. R. had a birth weight of 3.7 kg and was euglycemic during her first few days of life in the hospital. By 3 years of age, her pediatrician noted that her weight and height were both accelerating above the 95th percentile, and at 6 years of age, her BMI was 30 kg/m2, well above the 95th percentile for age. At 12 years of age, she began attending a local Weight Watchers program with her mother. Despite her efforts at dietary control and exercise, her BMI continued to increase at a rate of about 3 kg/m2 per year. Her family history was remarkable for diabetes, hypertension, and hyperlipidemia in both of her parents and all of her grandparents. Her mother had a Roux-en-Y gastric bypass when T. R. was 14 years of age. Her review of systems was positive for snoring, daytime somnolence, limited exercise tolerance, and oligomenorrhea. She was an excellent student but shied away from after-school activities and was uncertain about attending college after high-school graduation. On physical examination, she had hypertension, acanthosis nigricans, and extensive striae. Laboratory studies revealed insulin resistance, normal 2-hour glucose tolerance test result, elevated total and low-density lipoprotein cholesterol levels, and elevated alanine and aspartate aminotransferases. Her electrocardiographic and echocardiographic recordings were normal; however, polysomnography revealed a markedly elevated apnea-hypopnea index with multiple apnea events associated with oxygen desaturation. She and her mother requested that she be evaluated for bariatric surgery. After a 6-month period of weight maintenance, supported by dietary modification and limited exercise, she underwent a Roux-en-Y gastric bypass. Postoperatively, she was prescribed a restricted diet, supplemented with protein, minerals, and vitamins. Subsequently, she was able to reintroduce a wide variety of foods. Six months after surgery, her weight was 110 kg, her BMI was 43, and all laboratory studies had normalized, including polysomnography. As a valedictorian at her high-school graduation, 18 months after surgery, her weight was down to 87 kg and her BMI was 35.4. With improvement in her self-esteem, she looked forward to entering an out-of-state college soon thereafter.

PREVALENCE The United States is experiencing a dramatic increase in pediatric obesity. Since 1971, the prevalence of overweight has increased from below 5% to almost 20% for non-Hispanic white children aged 6 to 11 years and from just above 5% to 17% among 12- to 17-year-olds (Ogden et al, 2002). Similar increases occurred for non­Hispanic black and Mexican American youth. Although the risk of overweight varies with gender, socioeconomic status (SES), and ethnicity, these associations have weakened over time and, in some cases, reversed. Non-­Hispanic white boys 2 to 9 years of age of lower SES are at greater 592

risk of overweight, whereas non-Hispanic white girls in this age group with higher SES are at greater risk than those of lower SES. This trend among girls reverses with age, such that lower SES non-­Hispanic white girls 10 to 18 years of age are at greater risk than non-Hispanic white girls of higher SES. For non-Hispanic black girls 10 to 18 years of age, the reverse is true, with greatest risk seen in the higher SES group. In the period 19992002, the highest rates of overweight were seen among the groups of non-Hispanic black girls 10 to 18 years of age of higher SES (38%) and the middle SES Mexican American boys 10 to 18 years of age (35.2%).

Chapter 61    Child and Adolescent Obesity

MEDICAL AND PSYCHOLOGICAL SEQUELAE Obesity is associated with a variety of medical and psychological sequelae, all of which may begin in childhood (Must and Strauss, 1999). It is no longer unusual to encounter overweight children with type 2 diabetes, obstructive sleep apnea, nonalcoholic steatohepatitis, pseudotumor cerebri, hypertension, hyperlipidemia, polycystic ovary syndrome (girls), and the metabolic syndrome. Obesity in childhood and adolescence may have longterm consequences on adult health. Not only is the likelihood of adult obesity greatly increased for adolescents who are overweight, but so too is the presence of cardiovascular risk factors during the adolescent years, all of which, including hypertension, elevated low-density lipoprotein levels, elevated triglyceride levels, and reduced high-density lipoprotein levels, remain significant risk factors for adult cardiovascular disease. The severity of atherosclerotic lesions in coronary arteries and the aorta is associated with body mass index in autopsy studies of children and young adults. The social and psychological sequelae of obesity in childhood and adolescence also deserve attention. Increased body fatness is associated with earlier physical and sexual maturation, which in turn may have social consequences, including poor self-esteem and disturbed body image. Preoccupation with weight is often accompanied by abnormal eating behaviors, leading to binge eating, unhealthy dieting, and, in some cases, anorexia. The stigma of obesity may lead to difficulty in establishing peer relationships and social isolation. Rejection on the basis of body size and shape begins during the preschool years and can continue throughout life, even leading to discrimination in college acceptance and employment. These social and psychological consequences also extend into adult life, including lower household income, fewer years of education, higher rates of poverty, and lower marriage rates, for adults who were overweight at age 16 years (Gortmaker et al, 1993). Overweight concerns, body dissatisfaction, and depressive symptoms are prevalent among school-age boys and girls of varying ethnicity and socioeconomic status ­(Erickson et al, 2000; Robinson et al, 2001a). In a sample of severely overweight adolescents evaluated for bariatric surgery, 30% met criteria for clinically significant depression with use of a self-report measure and 45% met criteria based on parent report (Zeller et al, 2006). Quality of life measures also suggest that health-related quality of life is affected by obesity and that the effect may be as great as that seen for children and adolescents diagnosed with cancer (Schwimmer et al, 2003).

DIAGNOSIS OF OBESITY Body mass index (BMI) is the currently recommended metric for the assessment of overweight in the pediatric age group. Although methods exist for the estimation of body fatness, including skin fold thickness, underwater weighing, air plethysmography, and bioelectric impedance, these are not widely employed in clinical care. In this chapter, the term obesity is used in reference to

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a condition of excessive body fatness; the term overweight is used in reference to individuals or groups of individuals whose BMI is in excess of the 85th percentile for their age and gender. BMI, calculated by the formula [BMI = weight (kilograms) divided by the square of height (meters)], should be plotted on a standardized gender-specific percentile curve by age, such as those currently available from the Centers for Disease Control and Prevention (Figs. 61-1 and 61-2). BMI at or above the 95th percentile for age and gender is defined as obese, whereas BMI at or above the 85th percentile and below the 95th percentile is defined as overweight.

DEVELOPMENT OF ADIPOSITY Dietz (1994) has suggested that there may be three “critical periods” in the development of obesity, corresponding to periods of adipose tissue proliferation: gestation and early infancy, ages 5 to 7 years, and adolescence. The role of the prenatal period in the later development of obesity is still unclear, although metabolic influences on the developing fetus, such as those that occur in the presence of gestational diabetes, may have long-term consequences (Whitaker et al, 1998). During the first year of life, children tend to accumulate “baby fat,” followed by a relative reduction in body fatness during the next several years, followed again by an increase in their BMI beginning at 5 to 6 years of age and continuing through puberty. Longitudinal studies of risk factors for adult obesity have generally shown that with increasing age, the overweight child or adolescent has an increasing likelihood of obesity in adult life, thereby providing justification for counseling of any child whose BMI exceeds the 85th percentile about risk of later overweight.

ETIOLOGIC FACTORS The multifactorial nature of child obesity suggests an important interaction of genetic predisposition, family environment, and individual behavior. Whether the etiology of obesity is more genetic or behavioral, the clinical approach to the evaluation and treatment of this problem requires that all factors be acknowledged. Dietz and Robinson (1993) suggested that as in other diseases reflecting an interaction of host and environment, the most appropriate perspective is that genetics influences susceptibility to obesity but that the genetic predisposition to obesity can be modified by attention to environmental factors affecting calorie intake or energy expenditure. Factors influencing the development of body fatness during childhood and adolescence include calorie intake and energy expenditure. Although differences in calorie intake or energy expenditure might account for differences in body fatness between individuals, it has been difficult to consistently demonstrate such differences, even in well-performed naturalistic studies. Small differences in daily food intake or physical activity, when extended for long periods, may account for the excessive weight gain of some children.

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CDC Growth Charts: United States BMI

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Body mass index-for-age percentiles: Boys, 2 to 20 years

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Figure 61-1.  Percentiles of BMI for boys 2 to 20 years of age. (From http://www.cdc.gov/growthcharts.)

Excessive parental control rather than self-regulation of dietary intake may also be an important risk factor for overweight. Johnson and Birch (1994) studied the relationship of adiposity to children’s ability to selfregulate dietary intake and found that overweight girls were less likely to compensate for their intake at a previous meal than were thinner girls. Parents may influence their children’s eating behavior without clearly influencing their risk of overweight (Drucker et al, 1999). The effect of parental control on food intake remains somewhat uncertain, as it was not seen in an ethnically diverse sample with greater variability in socioeconomic status (Robinson et al, 2001b). Child temperament may also play a role in feeding and weight gain. During infancy, difficult children (those with higher negativity and intensity and lower ­ rhythmicity, approaching, and adaptability) may be more irritable,

with parents then using feeding as a soothing technique (Carey, 1985). This hypothesized relationship was supported by a longitudinal study of children from birth to 9.5 years of age; children whose parents reported tantrums over food and whose temperament scores were higher on anger and frustration and lower on soothability had an increased risk of later overweight (Agras et al, 2004). Inactivity may also contribute to increased weight gain. Excessive television viewing has received attention as a potential cause of obesity. In the Framingham Children’s Study, time spent watching television was associated with changes in body fatness over time (Proctor et al, 2003). Interventions to decrease sedentary behaviors, including television viewing, or to increase physical activity are associated with changes in percent overweight and aerobic fitness (Epstein et al, 2000). Likewise, efforts to reduce television viewing can directly influence

Chapter 61    Child and Adolescent Obesity

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CDC Growth Charts: United States BMI

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Figure 61-2.  Percentiles of BMI for girls 2 to 20 years of age. (From http://www.cdc.gov/growthcharts.)

change in BMI and prevalence of obesity over time in nonclinical populations (Robinson, 1999).

ROLE OF THE PRIMARY CARE PHYSICIAN IN THE MANAGEMENT OF CHILD AND ADOLESCENT OBESITY The primary care physician has a number of important roles in the care of overweight children, beginning with calculation of the BMI at each visit and the identification of overweight children. Although physicians may be reluctant to raise the issue of overweight in an effort to avoid labeling of the affected child, without such identification, it is unlikely that the child’s weight status will be addressed in the office setting. A comprehensive history and physical examination are generally sufficient to rule out underlying endocrine and obesity disorders, and

the primary care physician can focus on the medical and psychological comorbidities of obesity during the evaluation process. Depending on the availability of other resources in the community and the needs of the child or family, the physician might consider the additional consultation of a dietitian, psychologist, family therapist, and group treatment program. Even if the child engages in a weight management program independent of the physician’s office, it remains important to monitor the nutritional adequacy of any dietary changes and safety of exercise and other physical activity accompanying the program and to monitor the child’s BMI over time. Pediatricians often express frustration in their efforts to engage patients and their parents in meaningful weight management efforts. This frustration may also be linked to a lack of confidence in their own or others’ ability to successfully provide weight management counseling. Patients and their parents often appear to lack sufficient

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motivation to make significant change in eating behaviors, dietary composition, and physical activity. There is a growing interest in the application of motivational interviewing techniques to pediatric obesity treatment (Resnicow et al, 2006). Motivational interviewing uses a nonjudgmental and supportive mode of communication between physician and patient, designed to enhance motivation for behavior change, rather than the more traditional emphasis on the transfer of information about healthy diet or exercise. The physician must engage in active reflective listening to respond effectively to the patient’s or parent’s questions and statements. Once the patient or parent acknowledges both concern about the problem of overweight and a belief that behavior change will be effective in overcoming the problem, it then becomes much more likely that goals for behavior change can be articulated, agreed on, and ultimately achieved. The pediatrician may wish to engage the consultation of other clinicians in the treatment of his or her overweight patients. In particular, the use of pediatric specialists for assistance with the management of comorbidities, such as diabetes, hypertension, sleep apnea, pseudotumor cerebri, and polycystic ovary syndrome, should be considered. In caring for patients with very severe overweight, consultation with a pediatric obesity specialist should also be considered, especially if the need for pharmacotherapy or bariatric surgery is under discussion.

DIAGNOSTIC EVALUATION History Less than 2% of overweight children have an underlying endocrinopathy, such as hypothyroidism or Cushing disease, or one of the recognized obesity syndromes, such as the Prader-Willi or Bardet-Biedl syndrome (Table 61-1). In general, nondysmorphic overweight children with normal or above-average height, normal intelligence, and normal gonadal development do not require further laboratory investigation for underlying genetic or endocrine disorders. The child’s past medical history should be reviewed with attention to early hypotonia, feeding difficulties, or Table 61-1.  Examples of Obesity Syndromes Prader-Willi Syndrome Early hypotonia Early feeding difficulty Early failure-to-thrive Developmental delay Later profound hyperphagia

Bardet-Biedl Syndrome Intellectual disability Hypogonadism Polydactyly Retinitis pigmentosa Optic atrophy Cataracts Microphthalmia Colobomas

developmental delay. Current and past medication use, suspected food allergies, hospitalizations, and surgeries should also be noted. The review of systems should include particular attention to symptoms associated with comorbidities of obesity, such as persistent headaches, as seen in pseudotumor cerebri; excessive daytime sleepiness, snoring, and enuresis, all of which may suggest the possibility of obstructive sleep apnea; persistent hip or knee pain, as seen with slipped capital femoral epiphyses or tibia vara; and, for pubertal girls, oligomenorrhea or amenorrhea, hirsutism, and excessive acne, which may suggest the presence of polycystic ovary syndrome. The child’s pattern of eating should be reviewed with attention to rapid eating, large portion sizes, multiple frequent meals throughout the day, excessive snacking, binging, and nighttime eating. A common pattern seen among older children and adolescents involves skipping breakfast and lunch, followed by a large dinner and after-dinner snacking. Diet records, kept for a period of weekend and weekdays, can be used to analyze the nutritional composition of the child’s diet and to identify opportunities for dietary modification, as with poor food selection or excessive portion sizes. The child’s physical activity should also be reviewed, supplemented by a physical activity record, to describe the amount and intensity of physical activity. It is important to document periods of inactivity, including use of video games, computers, and television, as these are discrete sedentary behaviors that can be targeted for change. Evaluation of the overweight child should include a psychological assessment, which should focus on ways in which the child’s weight, or that of other family members, might influence the family’s functioning as well as any factors that may influence eating habits or affect the ability to participate in a treatment program. This is an opportunity to discuss how the child’s eating habits or obesity has an impact on the other family members and ways in which the child’s obesity may affect peer relationships. The presence of significant psychopathology, including prior eating disordered behaviors, in the child or parents necessitates further psychiatric evaluation.

Physical Examination A careful general physical examination should be geared to the identification of underlying endocrine or other syndromes and to the identification of problems that may contribute to or be a consequence of the child’s obesity (Table 61-2). Patients with normal stature, normal cognitive development, and normal gonadal development are unlikely to have a primary endocrine or genetic diagnosis underlying their obesity.

Laboratory Evaluation and Diagnostic Studies In patients suspected of having the Prader-Willi syndrome, fluorescent in situ hybridization analysis has become the recommended approach to the laboratory diagnosis. Hypothyroidism can be assessed by serum levels of thyroxine, triiodothyronine (by radioimmunoassay), and thyroid-stimulating hormone. In patients with possible Cushing syndrome, cortisol levels and a dexamethasone suppression test should be obtained.

Chapter 61    Child and Adolescent Obesity

Given the increasing prevalence of many of the comorbidities of obesity in the pediatric age range, laboratory and diagnostic studies are indicated for all children whose BMI exceeds the 95th percentile for age as well as for children with BMI above the 85th percentile and clinical signs of any comorbidities (Table 61-3).

Psychological Assessment A psychological assessment of the child and family can be very helpful and may provide important information about the family’s concerns and ability to participate in further evaluation and in treatment. It is useful to observe the interaction of family members and to observe their expressions of concern for and criticism or support of the child in dealing with this problem. If the opportunity presents itself, it is also useful to note parents’ responses to the child’s requests for food during the visit. If there is any suspicion of child or family psychopathology, an experienced psychologist or family therapist should be consulted during this process.

TREATMENT APPROACHES Recent publications provide a series of recommendations for the management of overweight children and adolescents. The Expert Panel on Child Obesity of the Maternal and Child Health Bureau met in March 1997 and agreed on the use of BMI to assess overweight ­status

Table 61-2.  Important Physical Findings Related to Obesity Short stature (underlying endocrine or genetic diagnosis) Blood pressure (hypertension) Papilledema (pseudotumor cerebri) and retinitis pigmentosa (Bardet-Biedl syndrome) Thyromegaly Loud pulmonic second sound (increase in pulmonary vascular resistance) Hepatomegaly (enlarged fatty liver) Hypogonadism (Prader-Willi syndrome and other genetic ­disorders) Buffalo hump, truncal obesity, and striae (Cushing syndrome) Acanthosis nigricans (type 2 diabetes mellitus or insulin ­resistance) Hirsutism and excessive acne (polycystic ovary syndrome) Small hands (Prader-Willi syndrome) Bowing of the legs (Blount disease)

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and on an algorithm based on BMI percentile, age, and associated comorbidities. The Panel emphasized that intervention should begin early, rather than waiting for the development of worsening overweight or associated comorbidities. The Panel also recommended that clinicians evaluate the family’s readiness to participate in a program dependent on behavior change and that all family members should be involved in the weight management process, including dietary change and physical activity (Barlow and Dietz, 1998). ������������������ The Panel’s recommendations have been updated and expanded recently (Barlow and the Expert Committee, 2007).��

Goals Treatment should aim for modest, gradual change over time, with an emphasis on implementing small, permanent changes in diet and activity. Families should learn to use self-monitoring as a key component of the behavior change process and should set reasonable targets for weight maintenance or weight loss, depending on the age of the child and the severity of his or her overweight. Recommendations based on age and BMI are included in the new Expert Committee Report. Children 6 years of age and older should be encouraged toward weight loss if their BMI is at or above the 95th percentile, as should those 12 years of age and older with a BMI between the 85th and 94th percentiles in the presence of a comorbidity. Children between 2 and 5 years of age should be encouraged to lose weight only in the presence of a BMI at or above 21 kg/m2. It is not always easy to set a specific target weight for the child. One approach is to use the child’s BMI curve to identify the current thresholds for 85th percentile and 95th percentile BMI for age. The current height is then used to calculate the weight loss that would put the child at each of these thresholds. Such a goal may be achievable with periods of weight loss alternating with periods of weight maintenance. Behavioral treatment should support change in diet and exercise without placing the child at risk for calorie insufficiency. Depending on the age of the child and the severity of obesity, change in behavior may be used to maintain a young child’s weight, allowing linear growth to proceed (producing a change toward lower degree of overweight or fatness), or to foster moderate weight loss in the older child (½ to 1 pound per week) or adolescent (1 to 2 pounds per week). By closely ­ monitoring

Table 61-3.  Recommended Laboratory Studies for Comorbidities Suspected Comorbidity

Laboratory or Diagnostic Study

Type 2 diabetes mellitus Insulin resistance Hyperlipidemia Nonalcoholic fatty liver disease Polycystic ovary syndrome

Fasting blood glucose concentration; if elevated, add 2-hour glucose tolerance test* Insulin level* Fasting lipids (total cholesterol, low-density lipoprotein, high-density lipoprotein, triglycerides)* Liver function tests (aspartate and alanine aminotransferases)* Abnormal levels of testosterone, free testosterone, dehydroepiandrosterone sulfate, and sex hormone– binding globulin, with normal levels of prolactin, insulin-like growth factor 1, thyroid hormones, and 17-hydroxyprogesterone Polysomnography, electrocardiography Knee radiographs Hip radiographs Chest radiography, echocardiography Computed tomography of the head

Obstructive sleep apnea Blount disease Slipped capital femoral epiphyses Heart failure Pseudotumor cerebri *Indicates

studies recommended for all patients with BMI greater than 95th percentile; all others if suspected by history or physical examination findings.

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the child’s diet, rate of weight loss, and continuing growth in height, nutritional adequacy of the diet can be ­confirmed. In addition to weight loss, it is important to emphasize associated goals of improved fitness, self-esteem, social interaction, and family harmony. These outcomes can all be achieved without an emphasis on weight loss and may be enhanced by a focus on the development of healthier eating habits and increased physical activity for the whole family. A general word of caution should also be emphasized with regard to the overzealous application of any weight management strategy for the child or adolescent. Reports of significant retardation of growth, associated with the dietary treatment of hypercholesterolemia and with fear of the development of obesity, should be viewed as the adverse outcomes of inadequately supervised or misguided attempts at dietary manipulation. In addition, 20% of 137 patients who were followed up after participation in family-based group treatment reported being treated for psychiatric disorders during the 10-year follow-up (Epstein et al, 1994).

Family Involvement Child and adolescent obesity is situated within a family context. There are typically other family members who have struggled with weight and whose experience can be extremely valuable in helping develop a realistic set of goals for the child and family. The tendency for families to feel defeated by obesity comes from their unrealistic expectation of dramatic and continued change. The family’s involvement is critical to the evaluation and management of child obesity. Parents are often confused by what they have read and thought about the origins of their child’s obesity. Because obesity has both strong genetic and behavioral contributions, parents often feel guilty about their child’s obesity and may have already experienced failure in trying to intervene. Because obesity is so resistant to intervention, the family may feel hopeless and at a loss. Efforts to explain the

causes of the child’s obesity are rarely successful and often lead to confusing or inadequate explanations for the family. For example, rather than using the dietary history as a means of proving the presence of excessive dietary intake, one should use the dietary history as a means of identifying opportunities for dietary change. Likewise, in discussing the child’s regular physical activity, it should be possible to identify opportunities for increasing physical activity. One can approach intervention as a process of gradually modifying the child’s eating behavior and physical activity over time, in the context of the whole family. It is critical that the family engage in this process in an active way and agree to initiate and to maintain change in the whole family’s food and exercise habits.

Behavioral Intervention For families who appear to be reasonably functional and motivated, the initial strategies are focused on gradual alterations in the child’s eating and physical activity (Table 61-4). These behavioral strategies include goal setting, self-monitoring, record review, contracting, praise, environmental control, cognitive restructuring, anticipation, periodic reassessment, and maintenance. Intervention does not require “calorie counting” or specific calorie intake reduction. An alternative approach is to categorize foods as more or less desirable and to use behavioral techniques that lead to the reduction of less desirable foods and encouragement of more desirable foods. One such system of categorization, the “stoplight diet,” categorizes foods as “red light,” “yellow light,” and “green light” (Epstein et al, 1994). By identifying foods in this way, parents can support the child’s efforts to reduce intake of red-light foods and increase intake of foods from the other two categories. Gradual reduction in intake of red-light foods can be rewarded and sustained in association with goals of weight loss or maintenance. A discussion of dietary approaches to weight management in children would not be complete without some

Table 61-4.  Behavioral Treatment Components Goal setting Self-monitoring Daily record review Contracting Praise Environmental control

Cognitive restructuring Anticipation Reassessment Maintenance

Set weekly challenging but achievable goals for change in diet, physical activity, and sedentary behavior. Self-monitoring increases behavioral awareness of behavior change and facilitates reinforcement. Without self-monitoring or monitoring by parents, it is impossible to assess progress in behavior change over time. Daily review with a parent helps provide feedback and reinforcement for behavior change. After setting of realistic and explicit goals each week, the parent and child contract for agreed on behavior change. Rewards should be simple, easy to administer, and inexpensive. Rewards should be deliverable ­immediately (i.e., weekly or daily). Parents can learn to use praise as a powerful tool to reinforce and to maintain desired behavior change. Praise should be specific to the behavior. Criticism and punishment are less effective and may be detrimental. Parents can help by identifying factors within the environment that promote overeating or inactivity. Examples of environmental control include removal of high-fat, high-calorie foods from the household, increasing the availability of cut-up vegetables rather than chips or sweets for snack time, avoidance of television viewing during mealtimes, reducing the amount of time indoors during daylight hours, and increasing the expectation for daily physical activity. Parents and children learn alternative ways to think about their beliefs and behaviors to reduce the tendency to feel bad about their struggle with weight. It is important to anticipate obesity-promoting situations and to plan specific strategies for parties, travel, and holidays. Periodic reassessment enables the child and family to identify lapses in desired behavior change and to reinstitute previously successful strategies, before feelings of frustration and failure develop. Ongoing reassessment of goals, strategies, and progress

Chapter 61    Child and Adolescent Obesity

mention of low-carbohydrate or low–glycemic index diets. Although the “low-carb” diet achieved enormous popularity in the United States during the 1990s, its use among children and adolescents has been more limited. A low–glycemic index diet is one that emphasizes foods that produce only a small increase in blood glucose concentration after consumption of a standard amount of carbohydrate. Examples of high-glycemic carbohydratecontaining foods are highly refined grains and potatoes; nonstarchy vegetables, legumes, and fruits produce smaller increases in blood glucose concentration and are considered to be low-glycemic foods. The “stoplight approach” has been applied in a study evaluating the feasibility of using a low–glycemic index diet for children 5 to 12 years of age (Young et al, 2004). Unfortunately, there have been relatively few controlled studies of behavioral treatment for child and adolescent obesity. A recent meta-analysis identified treatment studies published between 1966 and 2005, of which only nine studies met all of the criteria specified by the authors, including use of a described dietary intervention, inclusion of a comparison group (either untreated or treated with an alternative approach), and use of weight change or BMI change as an outcome (Gibson et al, 2006). These studies varied in duration from 8 to 40 weeks and in duration of initial followup from none to 24 months and provided support for energy restriction as being useful in short-term weight loss, but no conclusions could be drawn with regard to longer term weight loss or maintenance of weight loss. Epstein and coworkers (1994) have reported ­followup results of their family-based group treatment program. Combining subjects from a number of their treatment studies, at the 5-year follow-up they found that reinforcement of both child and parent behavior or reciprocal targeting of children and parents yielded better results than did a nonspecific control condition in which children were reinforced only for attendance at treatment meetings. Predictors of child success included self-monitoring of weight, changing eating behavior (eating fewer red-light foods and more selection of low-calorie snacks), parent-reported use of praise, and change in parent percent overweight. At the 10-year ­follow-up, about one third had maintained a decrease in percent overweight of 20% or more, and nearly 30% were no longer overweight.

Very Low Calorie Diets Very low calorie diets, generally providing fewer than 800 kcal per day, became widely available for outpatient use in the treatment of adult obesity in the 1980s. These diets, sometimes called protein-sparing modified fasts, were associated with significant medical risks (electrolyte abnormalities, arrhythmias, and sudden death) but became widely marketed as part of many commercial weight loss programs. Despite their general success in supporting rapid weight loss, most patients experienced subsequent weight regain once the very low calorie diet was discontinued. These extremely hypocaloric diets have been used on a limited basis in the pediatric population, generally in an inpatient setting, with close medical supervision.

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Surgery Bariatric surgery includes any surgical procedure performed with the intention of inducing or supporting weight loss among overweight individuals, including procedures that foster a reduction in calorie intake by restricting the size of the stomach or that induce a malabsorptive state by excluding varying portions of the bowel. Although developed and modified over the years to be used primarily with adult patients, these procedures have become increasingly applied to the treatment of severely overweight adolescents. The bariatric surgery most commonly performed today is the Rouxen-Y gastric bypass, which combines elements of both gastroplasty (15- to 30-mL pouch) and intestinal bypass (75 to 150 cm). Recent improvements in laparoscopic techniques and equipment have made it possible for the Roux-en-Y to be performed with the laparoscope. An alternative procedure, which does not permanently alter the anatomy of the stomach and intestine, involves placement of a band around the upper stomach with the option of using saline injected into a subcutaneous reservoir to adjust the tightness of the band. Although adjustable gastric banding can be reversed by removal of the band, its use in adolescent populations has been limited by lack of Food and Drug Administration approval of the device for patients younger than 18 years. In 2004, an expert panel of surgeons and pediatricians developed a practice guideline for bariatric surgery in adolescent patients (Inge et al, 2004). On the basis of evidence available at that time, the group recommended the Roux-en-Y as having the best efficacy and safety of the procedures available and stressed the importance of gathering additional data concerning other procedures, such as the adjustable band. The importance of evaluating and treating adolescents in a pediatric setting rather than in an adult setting was also emphasized. The criteria for performance of bariatric surgery in adolescent patients emphasize physical and psychological maturity (Table 61-5). Data concerning outcomes of bariatric surgery for adolescents have begun to emerge in terms of outcome and safety. A group of 10 patients, 15 to 17 years of age, had a Roux-en-Y bypass at one center and had a mean weight loss of 54 kg, with only one of the 10 failing to achieve weight loss in excess of 10 kg; however, four patients suffered late postoperative complications, including an incisional hernia, cholelithiasis, protein-­calorie malnutrition, and small bowel obstruction (Strauss et al, 2001). Another series published in 2006 described 1-year outcomes for 39 patients operated on at three centers between 2001 and 2003, ranging in age from 13 to 21 years and all meeting the criteria described before (­Lawson et al, 2006). Postoperative weight loss produced a change in mean BMI for the group from 56.5 kg/m2 to 35.8 kg/m2 with significant improvements in insulin sensitivity and lipid profiles. Postoperative complications included one death due to Clostridium difficile infection in a patient also under treatment for osteodystrophy.

Drug Treatment Only two drugs currently have approval of the Food and Drug Administration for obesity treatment in the pediatric age group, sibutramine (age 16 years) and orlistat

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Part VII   OUTCOMES—PHYSICAL FUNCTIONING

Table 61-5.  Criteria for Bariatric Surgery in ­Adolescents The adolescent patient should: Have a BMI > 40 kg/m2 with one of the specified serious obesity-related comorbidities (obstructive sleep apnea, ­pseudotumor cerebri, or type 2 diabetes mellitus) or have a BMI > 50 kg/m2 with less severe comorbidities (e.g., ­hypertension, nonalcoholic steatohepatitis, gastroesophageal reflux disease, dyslipidemia, venous stasis disease, weight-­related arthropathy, or impairment of activities of daily living) Have attained or nearly attained physiologic maturity Have had a minimum of 6 months in supervised weight ­management as determined with the assistance of the patient’s primary care physician Demonstrate commitment to comprehensive medical and ­psychological evaluation before and after surgery Agree to avoid pregnancy for at least 1 year postoperatively Be able and willing to adhere to nutritional guidelines ­postoperatively Demonstrate decisional capacity and provide informed consent Have a supportive family environment

(age 12 years). In a randomized, double-blind, placebocontrolled trial involving 82 adolescents in a behavioral treatment program, the group that received sibutramine (Meridia), a norepinephrine-serotonin reuptake inhibitor, experienced greater weight loss during the initial 6 months of treatment, but no difference was detectable after a 6-month open label treatment period (Berkowitz et al, 2003). Side effects led to discontinuation of the drug or reduction in dosage in 40% of participants. Although orlistat (Xenical), a gastrointestinal lipase inhibitor, has been available by prescription, it has recently been approved for over-the-counter sale, despite the known risk of unpleasant gastrointestinal side effects, including fatty/oily stools and fecal incontinence. Another drug available in the pediatric age group, metformin (Glucophage), is currently approved for pediatric use in type 2 diabetes mellitus, but its potential value in weight management is currently under investigation.

Follow-up The primary care provider should provide regular ­followup for the child who is involved in either an ­office-based or a group treatment program. This ­ follow-up can include periodic monitoring of the child’s weight and height as well as review of the child’s self-­monitoring records for diet and physical activity. For the child who is involved in a community-based, school-based, or ­hospital-based group treatment program, the primary care provider can provide added support, reinforcement, and encouragement to the child and family and help the family monitor their goals and progress along the way. Regular follow-up is suggested for at least 1 year and longer if possible.

PREVENTION In 2003, the American Academy of Pediatrics issued a policy statement emphasizing the importance of accurately identifying children who are overweight and ­beginning efforts to increase physical activity and to

reduce excessive calorie intake (American Academy of ­Pediatrics, 2003). Four specific behaviors that affect energy balance can be addressed during routine wellchild care, including television viewing, outdoor play, breastfeeding, and limiting the consumption of sugarsweetened drinks (Whitaker, 2003). In a 2005 report, the Institute of Medicine’s Committee on Prevention of Obesity in Children and Youth similarly recommended that health care professionals routinely track BMI, offer relevant evidence-based counseling and guidance, serve as role models with their own behaviors, and provide leadership in their communities (Institute of Medicine, Committee on Prevention of Obesity in Children and Youth, 2005). The Committee also recommended that medical professional organizations disseminate evidencebased clinical guidance, establish programs on obesity prevention, and coordinate with each other to present a consistent message and that educational and accreditation entities include obesity prevention knowledge and skills across the spectrum of professional ­education and in their certification examinations. A number of community- and school-based initiatives have been developed and tested during the past 10 years and found to have some impact on physical activity, television viewing, or dietary intake. In a schoolbased program designed to influence television viewing, students who were part of the intervention school not only decreased their television viewing but also showed less increase in BMI during the study period than did children in a control school, thereby demonstrating the potential for programs targeting specific behaviors rather than weight management (Robinson, 1999). Efforts to reduce access to soft drinks and other nutrientpoor products in the school environment are actively under way. Likewise, the influence of the physical environment on children’s physical activity is a focus of efforts toward increasing access to safe, accessible playgrounds, playing fields, and parks.

SUMMARY Although it is not a new problem, obesity among children and adolescents has reached a level of prevalence and severity never before seen in the United States and throughout the world. As a result of this “epidemic,” it is estimated that the current generation of U.S. children, born after the year 2000, will have a shorter lifespan than that of their parents and that one third of these children are likely to develop type 2 diabetes during their lifetimes! Other comorbidities of obesity, including hypertension, hyperlipidemia, nonalcoholic ­steatohepatitis, and obstructive sleep apnea, are being seen in a large number of overweight youth. A general lack of physical activity, coupled with increasing use of electronic media, and the increase in family meals eaten out of the home, especially at fast-food restaurants, have likely ­ contributed to the problem. Treatment efforts have been generally disappointing, except for intensive family-based behavioral group programs, whereas efforts at prevention, particularly on a school or community basis, have shown short-term promise.

Chapter 61    Child and Adolescent Obesity

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