Clinical Methodology & Calculation Standards

1. Body Mass Index (BMI)

Standard Formula: BMI = weight (kg) / [height (m)]²

For adult classification, we adhere strictly to the World Health Organization (WHO) Technical Report Series 854. Cutoffs: Underweight (<18.5), Normal/Healthy (18.5–24.9), Overweight (25.0–29.9), Obesity Class 1 (30.0–34.9), Obesity Class 2 (35.0–39.9), Obesity Class 3 (≥40.0).

Pediatric Architecture: For ages 2 to 19, adult fixed cutoffs are suppressed and replaced by CDC Growth Chart percentile interpretations based on age in months and biological sex.

2. Ideal Body Weight (IBW) Formulas

We implement four classic pharmacokinetic and clinical reference formulas:

• Devine (1974): Men = 50.0 kg + 2.3 kg × (inches > 60); Women = 45.5 kg + 2.3 kg × (inches > 60)
• Robinson (1983): Men = 52.0 kg + 1.9 kg × (inches > 60); Women = 49.0 kg + 1.7 kg × (inches > 60)
• Miller (1983): Men = 56.2 kg + 1.41 kg × (inches > 60); Women = 53.1 kg + 1.36 kg × (inches > 60)
• Hamwi (1964): Men = 48.0 kg + 2.7 kg × (inches > 60); Women = 45.5 kg + 2.2 kg × (inches > 60)

3. Energy Metabolism (Mifflin-St Jeor Equation)

Recognized by the Academy of Nutrition and Dietetics as the most clinically validated predictive resting metabolic equation for non-obese and obese adults:

Physical Activity Level (PAL) coefficients: Sedentary (1.2), Light (1.375), Moderate (1.55), Very Active (1.725), Extra Active (1.9).

4. Body Fat Estimation (U.S. Navy Method)

Utilizes logarithmic circumference measurements developed at the Naval Health Research Center (Hodgdon & Beckett, 1984) correlating to multi-compartment hydrostatic density benchmarks.