Basics
Description
Excess adiposity correlates closely with increased health risk for multiple medical and psychological disorders. Body mass index (BMI) is an easily obtained clinical measure to assess for increased body fat and concomitant health risks. BMI is calculated as weight in kilograms divided by height in meters squared. In children, age- and sex-specific percentiles define obesity.
- Children ≥2 years of age
- BMI 85 " 94%: overweight
- BMI 95 " 98% or BMI ≥30 kg/m2: obese
- BMI ≥99%: severe obesity
- BMI reference standards are not available for children <2 years of age. In this age group, overweight is defined as weight-for-length ≥95% for age and sex.
Epidemiology
Prevalence
2009 " 2010 U.S. National Health and Nutrition Exam Surveys (NHANES) data:
- Younger than age 2 years: 9.7% overweight ( ≥95 percentile weight-for-length)
- 2 " 5 years of age: 12.1% obese
- 6 " 11 years of age: 18% obese
- 12 " 19 years of age: 18.4% obese
- Higher rates in boys than girls
- Highest rates among Blacks and Hispanics
Risk Factors
- Obesity is most often a multifactorial condition with several risk factors:
- Parental obesity
- Maternal obesity in pregnancy
- Maternal history of gestational diabetes
- Intrauterine growth retardation
- Rapid weight gain in first 6 months of life
- Low socioeconomic status
- Genetics
- Obesity with developmental delay and/or dysmorphic features: Bardet-Biedle, Cohen, Prader-Willi
- Endocrine
- Obesity with poor linear growth: Cushing syndrome, hypothyroidism
General Prevention
- Encourage exclusive breastfeeding at prenatal visit and support breastfeeding throughout the 1st year of life.
- In formula-fed infants, watch for signs of overfeeding and rapid weight gain in 1st year of life. Educate families on the difference between hunger and oral suck reflex. Avoid rice cereal in the bottle.
- Recognize parental obesity as a significant risk.
- Incorporate early nutrition and activity counseling.
- Careful attention to BMI (and weight-for-length for children <2 years) with intensive counseling for children crossing percentiles.
- Stress importance of portion size and nutrient-rich foods (fruits and vegetables) as infants transition to a solid diet.
- Daily physical activity; limit screen time.
Pathophysiology
Complex interaction between genetics, hormones, environment, and behavior
- Short-term energy regulation: adaptation of meal size in response to energy needs. Hypothalamic neurons modulate sensitivity of nucleus tractus solitarius (NTS) neurons to satiety signals adjusting for changes in body fat mass.
- Long-term energy regulation: Hypothalamus senses and integrates energy balance signals including hormones such as insulin, leptin, ghrelin, and nutrients such as fatty acids, amino acids, and glucose.
- Leptin
- A negative feedback regulator " plays an important role in energy homeostasis.
- Communicates to hypothalamus changes in energy balance and fuel stored as fat.
- Increased fat mass results in increased leptin signaling which limits energy intake and supports energy expenditure.
- Decreased leptin promotes increased food intake, positive energy balance, and fat accumulation.
- Ghrelin
- Derived from the stomach, it is the only known peripherally acting orexigenic hormone. It stimulates appetite.
- All other gut-derived hormones are anorectic and limit food, optimize digestion and absorption, and avoid overfeeding.
- Adiponectin
- Insulin sensitizing, anti-inflammatory, and antiatherogenic
- Increased visceral fat results in reduced levels of adiponectin and increased proinflammatory milieu leading to insulin resistance and endothelial dysfunction. This predisposes to metabolic syndrome, diabetes, and atherosclerosis.
Etiology
Energy imbalance
- Excessive caloric intake: Calorie-rich foods and beverages consumed preferentially over nutrient-rich foods. Portion size is inappropriately large for age.
- Low-caloric expenditure: excessive sedentary time with TV, computers, video games, and handheld devices; limited daily physical activity
Commonly Associated Conditions
- Endocrine
- Type 2 diabetes mellitus
- Metabolic syndrome
- Polycystic ovarian syndrome (PCOS)
- Low vitamin D level
- Cardiovascular
- Respiratory
- Gastrointestinal
- Nonalcoholic fatty liver disease (NAFLD)
- Nonalcoholic steatohepatitis (NASH)
- Gallstones
- Gastroesophageal reflux (GER)
- Orthopedic
- Slipped capital femoral epiphysis (SCFE)
- Blount disease (tibial bowing)
- Skin conditions
- Acanthosis nigricans
- Hirsutism
- CNS: pseudotumor cerebri
- Psychiatric
- Binge-eating disorder
- Mood disorder: anxiety and depression
- Low self-esteem
Diagnosis
History
- Birth history: birth weight, maternal gestational weight gain, gestational diabetes
- Growth history: weight trajectory and age where percentiles were crossed
- Medical and/or social stressors
- Medical history: asthma, medications, obesity comorbidities
- Motivation
- Parental concern and desire for change and willingness to modify family 's behavior
- Child 's concern and motivation (as age appropriate)
- Family history
- Obesity
- Diabetes
- Cardiovascular disease
- Dyslipidemia
- Eating disorders
- Dietary history
- Sugar-sweetened beverages consumed
- Frequency of fruits and vegetables
- Frequency and type of snack foods
- Frequency of fast food
- Eating behavior
- Family meals
- TV viewing during meals
- Recognition of satiety
- Binge eating with or without loss of control
- Physical activity
- Total screen time including phone and handheld devices
- Duration, intensity, and frequency of physical activity
- Sleep duration and pattern
- Previous attempts at weight loss
- Medication use (prescribed and OTC)
- Weight loss programs
- Review of systems
- Headache: pseudotumor cerebri
- Snoring/pauses in breathing, daytime somnolence: obstructive sleep apnea (OSA)
- Abdominal pain: reflux, gallstones
- Joint pains: hip pain (SCFE)
- Social isolation, emotional eating, behavior difficulties: depression
- Skin color changes (acanthosis nigricans)
- Irregular menses/amenorrhea: PCOS
- Polydipsia, polyuria: diabetes
Physical Exam
- Anthropometrics: weight, height, BMI, and BMI percentile
- Blood pressure for age, sex, and height percentile
- General physical findings suggestive of endocrine or genetic condition
- Short stature
- Dysmorphic facies
- Developmental delay
- Head, ears, eyes, nose, throat (HEENT)
- Papilledema
- Tonsillar hypertrophy and narrow pharyngeal opening
- Cardiopulmonary
- Poor aeration, wheezing
- Heart murmur
- Abdomen
- Hepatomegaly
- Abdominal pain
- Genitourinary: Tanner stage
- Musculoskeletal
- Range of motion at hips
- Abnormal curvature of lower leg
- Limp
- Skin
- Acanthosis nigricans
- Hirsutism
- Striae
- Psychological
- Mood: assess for evidence of depression
- Bullying, social isolation
Diagnostic Tests & Interpretation
Laboratory Tests: Lab
- BMI 85 " 94%ile without risk factor: fasting Lipid profile
- BMI 85 " 94%ile age ≥ 10 years with risk factors: fasting lipid profile, ALT, AST, fasting glucose
- BMI ≥ 95%ile Age ≥ 10 years: fasting Lipid profile, ALT, AST, fasting glucose, other tests as indicated by health risks
Abnormal Results
- Lipid panel: Obese children often have elevated LDL and triglycerides and low HDL.
- High LDL ≥130 mg/dL
- High triglyceride:
- 0 " 9 years old ≥100 mg/dL
- 10 " 19 years old ≥130 mg/dL
- Low HDL <40 mg/dL
- ALT value >2 times normal or >60 IU/L merits gastroenterology consult.
- Fasting glucose ≥126 mg/dL or random glucose ≥200 mg/dL supports a diagnosis of diabetes and warrants endocrinology consult.
- HgbA1c ≥6.5% suggests possible diabetes.
- Fasting glucose ≥100 mg/dL or HgbA1c ≥5.7% and ≤6.4% indicates impaired fasting glucose and a prediabetic state.
Diagnostic Procedures/Other
- Polysomnogram: history of snoring with pauses in breathing, narrow pharyngeal airway, or tonsillar hypertrophy (OSA)
- AP and frog-leg views of the hips: knee pain or hip pain, limitation or pain with internal rotation of hip (SCFE)
- Knee and lower extremity radiographs: abnormal curvature of the lower extremities, especially asymmetry (Blount disease)
- Echocardiogram: hypertension (LVH)
- Ambulatory blood pressure monitoring: elevated blood pressure/hypertension
- Abdominal ultrasound: elevated LFTs or abdominal pain (NAFLD, gallstones)
- Head CT: headache and papilledema on ocular exam (pseudotumor cerebri)
Treatment
Medication
- Orlistat: an intestinal lipase inhibitor that is the only FDA-approved medication for obesity in children ≥12 years
- Limits nutrient absorption
- Side effects: abdominal pain, oily stools, flatulence, fat-soluble vitamin deficiencies; self-limited success, poor compliance
- 5% weight loss, similar to placebo
- Not recommended for routine use
Additional Treatment
General Measures
- Prevention and treatment include healthy lifestyle behavior: Goal is to start with small incremental changes in lifestyle.
- Eliminate consumption of sugar-sweetened beverages including juice and sports drinks.
- Encourage nonfat milk and water.
- Increase servings of nutrient-rich foods such as fruits and vegetables with every meal and for snacks.
- Avoid skipping meals.
- Reduce eating out or takeout foods.
- Encourage family meals.
- Educate families about portion size as soon as solids are started and in early childhood.
- Advise 1 hour/day of moderate physical activity.
- Limit screen time to <2 hours a day.
- Weight loss goals
- Weight maintenance may be appropriate in younger children, as BMI will improve with increase in height.
- Older children and severely obese children can lose up to 2 lb a week.
Surgery/Other Procedures
Bariatric surgery indication
- Adolescents with a BMI ≥40 kg/m2 or BMI ≥35 kg/m2 with concomitant comorbidities such as diabetes and hypertension
- Lack of sustained weight loss on supervised weight-reduction program for 6 to 12 months
- Physical, emotional, and cognitive maturity
Ongoing Care
Follow-up Recommendations
- Assess BMI monthly and achievement of dietary and physical activity goals.
- Follow patient more frequently with weight gain and/or refer for nutrition counseling or a weight management program at a tertiary care center.
- Refer to subspecialist with diagnosis of accompanying comorbidities.
Prognosis
- Success is greater in younger children and children with lower BMIs.
- Better success if whole family involved in healthy lifestyle change
- Better success with self-monitoring
- Less success with severe obesity
- Poor prognosis if untreated mental health issues and/or lack of motivation
Additional Reading
- Barlow SE, Expert Committee. Expert committee recommendations regarding the prevention, assessment, and treatment of child and adolescent overweight and obesity: summary report. Pediatrics. 2007;120(Suppl 4):S164 " S192. [View Abstract]
- Daniels SR. Complications of obesity in children and adolescents. Int J Obes. 2009;33(Suppl 1):S60 " S65. [View Abstract]
- Ogden CL, Carroll MD, Kit BK, et al. Prevalence of Obesity in the United States, 2009 " 2010. Hyattsville, MD: National Center for Health Statistics; 2012. NCHS data brief no. 82.
- Spear BA, Barlow SE, Ervin C, et al. Recommendations for treatment of child and adolescent overweight and obesity. Pediatrics. 2007;120(Suppl 4):S254 " S288. [View Abstract]
Codes
ICD09
- 278.00 Obesity, unspecified
- 278.02 Overweight
- 783.1 Abnormal weight gain
- 278.01 Morbid obesity
- V85.53 Body Mass Index, pediatric, 85th percentile to less than 95th percentile for age
- V85.54 Body Mass Index, pediatric, greater than or equal to 95th percentile for age
ICD10
- E66.9 Obesity, unspecified
- E66.3 Overweight
- R63.5 Abnormal Weight Gain
- E66.8 Other obesity
- E66.09 Other obesity due to excess calories
- Z68.53 Body mass index (BMI) pediatric, 85th percentile to less than 95th percentile for age
- Z68.54 Body mass index (BMI) pediatric, greater than or equal to 95th percentile for age
- E66.01 Morbid (severe) obesity due to excess calories
SNOMED
- 414916001 obesity (disorder)
- 238131007 overweight (finding)
- 161833006 abnormal weight gain (finding)
- 450451007 Overweight in childhood (finding)
- 238136002 Morbid obesity (disorder)
FAQ
- Q: How do I broach such a sensitive topic with families?
- A. Review growth charts at every well-child visit and discuss any concerning increase in BMI. Describe in terms of healthy weight and the need to avoid comorbidities which become more likely with increasing BMI.
- Q: How do I counsel a family not interested in making lifestyle changes?
- A: Discuss the risk that an unhealthy BMI poses for the child. Describe small simple changes the family can make to alleviate this risk. Avoid assigning blame. Abnormal lab values may motivate a family to make changes.