How is obesity evaluated in children?

Evaluation of Obesity in Children

Obesity in children is primarily evaluated using Body Mass Index (BMI) percentiles specific to age and gender, with BMI ≥95th percentile defining obesity and BMI between 85th-94th percentiles indicating overweight status. 1

BMI Assessment and Classification

• BMI is calculated as weight (kg)/height (m)² or weight (lb)/height (in)/height (in) × 703 1
• Electronic health record programs automatically calculate and plot BMI percentile, or hardcopy growth curves are available at cdc.gov/growthcharts/cdc_charts.htm 1
• BMI percentiles are based on age- and gender-specific reference values because BMI distribution changes throughout childhood 1
• Classification criteria:
  • Overweight: BMI between 85th-94th percentile 1
  • Obesity: BMI ≥95th percentile 1
  • Severe obesity: BMI ≥120% of the 95th percentile 1

Medical Comorbidity Assessment

• Blood pressure measurement: Compare with norms for gender, age, and height published by National Heart, Lung and Blood Institute 1
• Lipid screening:
  • Begin at age 2 years if obesity is present 1
  • Abnormal values should be confirmed 2 weeks to 3 months after initial screen 1
• Diabetes screening:
  • Fasting glucose starting at age 10 years for children with obesity and 2 other diabetes risk factors 1
• Non-alcoholic fatty liver disease (NAFLD) screening:
  • Screen children with obesity aged 9-11 years 1
  • Coincides with lipid and diabetes screening 1
• Additional assessments:
  • Obstructive sleep apnea 1
  • Orthopedic pathology 1

Psychosocial Assessment

• Screen for depression and poor self-esteem 1
• Assess for bullying, which affects children with obesity regardless of demographics or social/academic standing 1
• Evaluate family dynamics and parental involvement, as consistent evidence shows improved outcomes when parents are involved in weight management programs 1

Special Considerations

• BMI tends to underestimate overweight in tall individuals and overestimate it in short individuals or those with high lean body mass 1
• Genetic conditions associated with obesity should be considered in appropriate clinical contexts (1-2% of obese children) 1
• Waist circumference may provide additional information about visceral adiposity and cardiometabolic risk 2
• Rapid changes in body composition during growth make assessment more complex in children than adults 1

Common Pitfalls to Avoid

• Relying solely on visual assessment: Parents recognize a child's overweight status in fewer than half of cases 1
• Using adult BMI cutoffs for children: Children require age- and sex-specific percentiles 1
• Failing to screen for comorbidities: The degree of obesity correlates with prevalence of cardiometabolic risk factors 1
• Overlooking psychological impact: Children with obesity face significant psychosocial challenges 1
• Neglecting family context: Parental involvement is crucial for successful weight management 1

Follow-up Recommendations

• Children with BMI greater than the 95th percentile should undergo comprehensive medical evaluation including blood pressure measurement, lipoprotein analysis, and fasting insulin and glucose determination 1
• Implement hierarchical screening for comorbidities for early identification before more serious complications develop 3
• Consider family-based interventions that address diet, physical activity, and behavioral change strategies 1