Obesity in Children and Adolescents

Background

• Obesity in children and adolescents is generally identified as a body mass index (BMI) > 95th percentile for age/sex, although there is no internationally accepted definition, and other classifications exist.
• Overweight and obesity in children can be classified as:
  • overweight - BMI ≥ 85th percentile but < 95th percentile for sex and age
  • obesity - BMI ≥ 95th percentile for sex and age
  • severe obesity - BMI ≥ 120% of 95th percentile or BMI ≥ 35 kg/m², whichever is lower
• Increased caloric intake, decreased energy expenditure, and genetic predisposition, which are affected by environmental and nonenvironmental factors, are the primary contributors to obesity.
• Hypothyroidism, growth hormone deficiency, and Cushing disease are a few endocrine disorders that increase risk for obesity in children.
• Prader-Willi, Turner, Fragile X, Bardet-Biedel syndrome, leptin deficiency, leptin receptor deficiency, pro-opiomelanocortin (POMC) mutation, and melanocortin 4 receptor (MC4R) mutation are some of the genetic syndromes that are associated with obesity.
• Perinatal and early childhood factors such as high birth weight (> 4 kg [8.8 lbs]), being at the highest percentiles for weight or BMI, growing rapidly during infancy, or having parents with obesity are predictors of subsequent obesity.
• Sugar-sweetened beverages and skipping breakfast are dietary risk factors associated with obesity.
• Excessive television or screen time (≥ 2 hours/day) and a television in a child's room are associated with elevated BMI.
• Psychological stressors, depression, anxiety, and poor sleep are associated with obesity.
• Complications of obesity in children include:
  • childhood and adolescent onset of hypertension, hyperlipidemia, prediabetes and diabetes, metabolic syndrome, nonalcoholic fatty liver disease, vitamin D and B12 deficiency, and obstructive sleep apnea
  • endocrine conditions such as diabetes, polycystic ovarian syndrome, and accelerated pubertal milestones
  • orthopedic issues including lower limb malalignment, musculoskeletal pain, and slipped capital femoral epiphysis
  • depression, low self-esteem, and poorer quality of life
  • increased mortality in adulthood

Evaluation

• Children should have weight and height assessed at all preventive visits starting at 2 years of age with the addition of blood pressure measurement at 3 years of age.
• Growth pattern, developmental milestones, and family history should be reviewed to assess for potential genetic or endocrinological causes of obesity.
• A detailed dietary history of the child as well as the dietary practices of the whole family should be obtained.
• Assess the presence or history of obesity-related risk factors including hypertension, dyslipidemia, diabetes, and ethnicity (African American, Native American, Latino, Asian American, and Pacific Islander) in the patient and in first- or second-degree relatives along with examination for signs of insulin resistance and determination of cigarette-smoking status.
• Children with a BMI > 85th percentile should undergo an assessment for obesity-related risk factors and diseases (Strong recommendation) including:
  • blood pressure for hypertension
  • fasting lipid profile for dyslipidemia
  • hemoglobin A1c or fasting plasma glucose for prediabetes and diabetes
  • alanine aminotransferase (ALT) for nonalcoholic fatty liver disease
• Other testing based on clinical presentation, signs, and symptoms may include sleep study for obstructive sleep apnea, serum and free testosterone, sex hormone-binding globulin, 17-hyroxyprogesterone, third-generation luteinizing hormone and follicle-stimulating hormone for polycystic ovary syndrome (PCOS), and genetic testing for associated syndromes.

Management

• Nonsurgical management of obesity
  • Recommendations for childhood obesity treatment include:
    • family-based, moderate-to-high intensity, age-appropriate, culturally sensitive, multicomponent interventions addressing behavioral strategies, and modifications to diet and physical activity
    • identification of behavioral and psychosocial issues as well as support for change
    • integrated chronic care model allowing for monitoring over time
    • multidisciplinary care team
  • There are 4 stages of obesity treatment -- prevention, plus structured weight management, comprehensive multidisciplinary intervention, and tertiary care interventions (including medications and bariatric surgery).
  • Dietary changes should be included in treatment and consideration should be given to the following:
    • involve a registered dietitian with knowledge of energy needs of growing children and adolescents
    • target eating behaviors such as decreasing overall caloric intake, decreasing consumption of calorie dense foods, eliminating consumption of sugar-sweetened beverages, and increasing consumption of fruits and vegetables
  • Physical activity and sedentary behavior changes should be included in treatment and consideration should be given to the following:
    • involve a physical or exercise therapist in setting goals and sustaining exercise habits
    • engage in minimum of 20 minutes/day of moderate-to-vigorous physical activity with a goal of 60 minutes/day
    • limit nonacademic screen time to 1-2 hours per day
  • Counseling, with motivational interviewing as the recommended approach, should address behaviors such as setting and monitoring goals and developing plans for daily eating and for increasing physical activity.
  • Multicomponent interventions addressing diet, physical activity, and behavior change with family member involvement are recommended.
  • Interventions of greater intensity, defined by more contact hours, appear to be more effective for treating obesity in children and adolescents.
  • Higher intensity of maintenance phase after obesity treatment program should be considered for long-term weight loss maintenance.
  • Regular follow-up is needed to monitor weight loss maintenance.
  • Consider laboratory testing as needed based on suspected comorbidities.
• Weight loss medications
  • Prescription medications
    • Orlistat is FDA approved for long-term weight loss in adolescents ≥ 12 years old with initial BMI ≥ 30 kg/m² or ≥ 27 kg/m² with obesity-related comorbidities.
    • Orlistat should be offered to adolescents as adjunct to reduced-calorie diet and lifestyle changes and prescribed only in consultation with a physician experienced in managing weight loss in adolescents.
    • Metformin appears effective, but is not FDA approved for obesity in children, only for type 2 diabetes.
    • Metformin may be considered, in addition to a comprehensive lifestyle weight loss program, in adolescents with severe obesity and insulin resistance.
    • Amphetamine-like medications are not recommended in children or adolescents due to adverse effects, potential for abuse, and lack of evidence demonstrating long-term weight loss efficacy.
    • FDA approved stimulant medications for use in adults include phentermine and lisdexamfetamine dimesylate (lisdexamfetamine approved for binge eating disorder only).
    • Other medications that have been used for management of obesity in adults include liraglutide, topiramate (with or without phentermine), buproprion (with or without naltrexone), and lorcaserin (prior to request for market removal issued by FDA, due to cancer risk).
  • Nonprescription weight loss supplements are generally not recommended.
  • Alli (nonprescription version of orlistat) is the only FDA approved nonprescription weight loss aid but is not approved for patients < 18 years old.
• Bariatric surgery
  • Bariatric surgeries involve anatomical changes that restrict gastric volume and/or bypass parts of the intestine which modify gastrointestinal hormones and bile acids secretion, neural mechanisms, and gut microbiota among many other possible mechanisms that lead to weight loss.
  • Bariatric surgery has typically been reserved for adolescents with severe obesity or obesity with associated risk factors or diseases who have not improved with behavioral approaches to weight management.
  • The Endocrine Society and American Society for Metabolic and Bariatric Surgery have guidelines for patients who may be candidates for surgical intervention.
  • A preoperative evaluation should be performed by a multidisciplinary team of experts in obesity.
  • The major surgeries performed include vertical sleeve gastrectomy, Roux-en-Y gastric bypass, and adjustable gastric banding.
  • Bariatric surgery may lead to reductions in BMI as well as the resolution or improvement in several obesity-related comorbidities in adolescents with severe obesity.
  • Postoperative management involves consideration of need for lifelong vitamin supplementation and monitoring, increased fertility, substance abuse, and mental health issues.
  • Complications may include nutritional issues, dumping syndrome, and lack of response to the surgery as well as those specific to the surgical type performed.