Fighting Childhood Obesity
ABSTRACT: Childhood and adolescent obesity cause adverse health and social consequences that persist into adulthood; prevention and intervention programs are essential.
CME OBJECTIVE: The reader will be able to define childhood overweight along with the appropriate evaluation and intervention options, based on BMI.
Frank A. Franklin, MD, PhD, no conflicts of interest
Excess weight in childhood is frequently a precursor to adult obesity. The array of associated physical disorders and emotional problems that often accompany obesity can persist, and frequently worsen, throughout life. Moreover, the probability of adult obesity increases as overweight children age: 50% of children who are overweight at age 6 will become overweight adults; by adolescence, the probability escalates to 80%.
"Although many adverse effects of childhood obesity take years to develop, even young children can suffer serious morbidity," says pediatrician Frank A. Franklin, MD, PhD, medical director of the joint UAB/Children's Hospital Children's Center for Weight Management. "Medical conditions such as type 2 diabetes mellitus, sleep apnea, hypertension, and risk factors for atherosclerosis — disorders once seen almost exclusively in adults — are now appearing in overweight children. Intervening early, before dietary and lifestyle patterns become fixed, reduces the chances of persistent obesity and its associated complications."
Scope of the Problem
The prevalence of childhood overweight in the United States is reaching epidemic proportions. Data from the 1999-2000 National Health and Nutrition Examination Survey (NHANES) show that between the 1960s and the late 1990s the number of overweight children aged 6 to 11 years more than tripled, increasing from 4% to 15.3% (JAMA. 2002;288: 1728-1732). This pattern was repeated in children aged 12 to 19 years, with prevalence rising from 5% to 15.5% during the same period. Increases were highest among Mexican American and African American adolescents. No gender differences were found.
"Currently, 1 in 5 US children is overweight, and the most recent NHANES data suggest children are being affected at younger ages — more than 10% of preschool children 2 to 5 years old are now overweight," Franklin says. "Additionally, another 15% of children and adolescents aged 6 to 19 years are considered at risk for overweight."
Definition and Assessment
In 2000, the Centers for Disease Control and Prevention (CDC) developed charts, based on body mass index (BMI), for defining overweight in children. "CDC growth charts outline the range of BMIs considered normal (50th percentile) for individuals aged 2 to 20 years," Franklin explains. "Children at or above the 95th percentile are categorized as overweight. Those between the 85th and 95th percentiles are considered at risk for overweight. Although no defined criteria exist for obesity in children, individuals above the 95th percentile warrant special concern.
"BMI should be evaluated annually in all children. For those children who are overweight, clinicians should measure blood pressure, fasting glucose, and fasting cholesterol and triglyceride levels to identify secondary complications," he says.
Causes and Complications
The dramatic upsurge in overweight children is being fueled by numerous societal factors, including increases in food variety, portion size, and snacking, as well as rising sugared beverage consumption and reduced physical activity.
Endogenous causes of childhood overweight are rare, Franklin emphasizes, and genetic syndromes, including Cohen and Bardet-Biedl, present with dysmorphic features and developmental delay, in addition to obesity. Linear growth failure is associated with Prader-Willi syndrome and endocrinologic causes of overweight, such as hypothyroidism and Cushing syndrome. Normal linear growth generally rules out these conditions, notes Franklin, adding that children with idiopathic overweight are often taller than average, usually above the 50th percentile of height for age, and frequently have a family history of obesity.
"Children identified as overweight should be evaluated for associated morbidity," he suggests. "Comorbid conditions include diabetes, obstructive sleep apnea, skin disorders, weight-related orthopedic problems, gallstone disease, depression, and cardiac risk factors."
Indications for Referral
"Children with BMIs at or above the 95th percentile, particularly those with a family history of obesity, should be counseled about lifestyle modifications by their clinician. If initial efforts fail, evaluation and treatment at a specialized center for pediatric weight management should be considered," Franklin says. "Children with BMIs above the 85th percentile with comorbid conditions, such as pseudotumor cerebri, sleep apnea, obesity hypoventilation syndrome, and orthopedic problems, should also be considered for referral. Waiting for a child to 'outgrow' weight problems, especially if they are older than 5 years, can exacerbate existing physical conditions and complicate future weight management."
An expert committee, convened by the Maternal and Child Health Bureau and other government agencies to develop recommendations for evaluation and treatment of overweight children, found that massively overweight children without comorbidities, including rare cases of severely overweight children younger than 2 years, also should be evaluated at a specialized center. (Barlow, SE, Dietz, WH. Obesity Evaluation and Treatment: Expert Committee Recommendations. Pediatrics. 1998:102(3):e29. Available at: www.pediatrics.org/cgi/content/full/102/3/e29. Accessed July 8, 2003.)
Behavior Modification
Behavior modification is the foundation of treatment at the Children's Center for Weight Management, which includes Let's Eat Smart and Exercise Right (LESTER), an 8-week program for children aged 6 to 11 years, and the year-long Healthier Weigh program for adolescents.
LESTER and Healthier Weigh program physicians, dietitians, and exercise physiologists meet weekly with children and their parents, focusing on diet and physical activity, as well as addressing emotional relationships within the family.
"We educate patients and parents about nutrition and the adverse effects of obesity, encouraging a realistic attitude to weight loss. For children with uncomplicated overweight, we counsel families on ways to make lasting changes in incremental steps, emphasizing healthy eating and increased activity levels — skills that promote reasonable slowing or cessation of weight gain," Franklin says.
"Helping families implement a healthier lifestyle is more important than attaining ideal body weight. For children with secondary complications of overweight, our goal is to improve or resolve their condition through appropriate medical therapy and weight loss." Bariatric surgery also is an option for a limited number of severely overweight adolescents with significant comorbidities, he adds, stressing that surgery should only be considered after all other weight-loss methods have failed.
A Special Challenge
"In younger children, food intake is largely controlled by parents or caregivers. Adolescents make more of their own dietary choices, but family eating patterns and attitudes are still crucial. Physicians can assess family readiness by asking how concerned family members are about the child's weight and what behaviors they are willing to change," Franklin says. "If parents are unwilling to modify their own behavior, or feel their child does not have a serious weight problem, weight management programs are unlikely to be successful. Plus, failure can harm the child, diminishing their self-esteem and impairing future weight-loss efforts.
"Societal messages often imply that overweight results from laziness or a lack of self-discipline, and both children and their parents frequently feel embarrassed and ashamed," he concludes. "With a compassionate and sensitive approach, clinicians can help children and their families realize overweight and obesity are chronic medical conditions that can be successfully treated."
For more information
Dr. Frank Franklin
1.800.UAB.MIST
mist@uabmc.edu
UAB Insight, Fall 2003