BMI Calculation and Classification
Yes, this patient has a BMI of 28.9 kg/m², which is greater than 25 kg/m² and classifies them as overweight. 1, 2
Calculation Method
Using the standard BMI formula 1, 2:
- Weight: 184.8 pounds = 83.8 kilograms
- Height: 67 inches = 1.70 meters
- BMI = 83.8 kg ÷ (1.70 m)² = 28.9 kg/m²
The formula can be calculated either as weight in kilograms divided by height in meters squared, or as weight in pounds divided by height in inches squared multiplied by 703. 1
BMI Classification
According to expert committee guidelines, this patient falls into the overweight category 1, 2:
- Normal/Healthy weight: BMI 18.5-24.9 kg/m² 3
- Overweight: BMI 25.0-29.9 kg/m² 1, 3
- Class I Obesity: BMI 30.0-34.9 kg/m² 1, 3
- Class II Obesity: BMI 35.0-39.9 kg/m² 1, 3
- Class III Obesity: BMI ≥40 kg/m² 1, 3
Clinical Significance and Health Risks
Being overweight (BMI 25-29.9 kg/m²) is associated with increased cardiovascular risk and metabolic complications compared to normal weight individuals. 2, 3
Specific risks include 2:
- Higher rates of type 2 diabetes
- Increased hypertension prevalence
- Elevated cardiovascular disease risk
- Greater likelihood of sleep disorders and osteoarthritis
Cardiovascular event rates in overweight individuals are elevated compared to those with normal BMI, though the risk is lower than in obese individuals. 2, 3
Additional Risk Stratification Required
BMI alone should not determine individual risk—waist circumference must be measured for complete assessment. 1, 2
Measure waist circumference to assess central adiposity 1:
- Men: >102 cm (>40 inches) indicates increased cardiovascular risk
- Women: >88 cm (>35 inches) indicates increased cardiovascular risk
Waist circumference is particularly important for risk stratification in patients with BMI 25-34.9 kg/m². 2, 3
Important Caveats
For Asian populations, this BMI would classify as obese rather than overweight, as lower thresholds apply. 3
Asian-specific cutoffs 3:
- Overweight: BMI ≥23 kg/m²
- Obesity: BMI ≥25 kg/m²
This reflects higher body fat percentages and visceral adiposity at lower BMI values in Asian populations, resulting in increased cardiometabolic risk. 3
BMI may misclassify very muscular or frail individuals, as it does not directly measure body composition. 4, 5, 6