Growth Assessment for 15-Year-Old Girl
BMI Calculation and Classification
This 15-year-old girl has a BMI of 25.6 kg/m² (71.85 kg ÷ 1.676 m²), which places her above the 95th centile for age and sex, meeting the definition of obesity according to UK WHO growth standards. 1, 2
Centile Interpretation
Height Assessment
- Height of 167.6 cm falls approximately at the 75th centile for a 15-year-old girl, indicating normal height for age 2, 3
- This is consistent with expected adult female height based on longitudinal growth data 3
Weight Assessment
- Weight of 71.85 kg is substantially above the 95th centile for a 15-year-old girl 1, 2
- For reference, the 95th centile weight for this age group is approximately 65-70 kg 1
- The discrepancy between height centile (75th) and weight centile (>95th) indicates disproportionate weight gain relative to height, which is clinically significant 1, 2
BMI Classification
- BMI of 25.6 kg/m² exceeds the 95th centile threshold, which defines obesity in adolescents 1, 2
- This BMI is concerning as it falls into the adult overweight category (BMI ≥25 kg/m²) even before completing growth 4
- International data shows this BMI level is elevated compared to European norms for 15-year-old girls 5, 6
Clinical Significance and Health Implications
Immediate Health Risks
- Weight status above the 95th centile in adolescence strongly predicts adult obesity and hypertension 7
- Adolescents with BMI between 75th-85th percentiles are up to 20 times more likely to become overweight adults 7
- This weight status increases risk for diabetes, cardiovascular disease, and certain cancers 4
Long-term Trajectory
- Overweight in adolescence tends to continue throughout life, making early intervention critical 4
- Boys with elevated childhood BMI show 4-5 times increased risk of developing hypertension in young adulthood 7
Recommended Clinical Actions
Monitoring Protocol
- Serial measurements every 6-12 months are essential to track BMI trajectory and response to interventions 1, 2
- Growth velocity and previous growth patterns should be reviewed to assess rate of weight gain 2, 8
- Blood pressure monitoring is indicated given the association between elevated BMI and hypertension risk 7
Intervention Framework
- Immediate lifestyle modification is warranted, focusing on dietary changes and increased physical activity 4
- Replace high-calorie foods with vegetables, fruits, whole grains, and beans 4
- Physical activity is essential for maintenance of healthful weight 4
- Address portion sizes, as restaurant meals typically exceed recommended daily caloric needs 4
Parental Context
- Consider mid-parental height calculation to determine if growth pattern aligns with genetic potential 8
- Family-based interventions are most effective for adolescent weight management 4
Key Clinical Pitfalls
- Do not dismiss this as "normal variation" - the BMI clearly exceeds healthy thresholds 1, 2
- Avoid focusing solely on single measurements; establish a monitoring schedule to track trajectory 1, 8
- Be aware that adolescent girls often misperceive their body weight, with some considering normal BMI as "too fat" 6
- Weight loss interventions should begin now rather than waiting, as obesity established in adolescence is difficult to reverse 4, 7