BMI Classification: Class II Obesity
A patient with a BMI of 37.5 kg/m² is diagnosed with Class II obesity according to the WHO classification system. 1, 2, 3
WHO BMI Classification System
The World Health Organization defines obesity classes as follows: 1, 3
- Normal weight: BMI 18.5–24.9 kg/m²
- Overweight: BMI 25.0–29.9 kg/m²
- Class I obesity: BMI 30.0–34.9 kg/m²
- Class II obesity: BMI 35.0–39.9 kg/m²
- Class III obesity: BMI ≥40.0 kg/m²
Why This Patient Has Class II Obesity
Since the patient's BMI of 37.5 kg/m² falls within the range of 35.0–39.9 kg/m², this definitively places them in the Class II obesity category. 1, 3
Clinical Significance of Class II Obesity
Class II obesity carries "very high" disease risk according to established classification systems, particularly for type 2 diabetes, hypertension, and cardiovascular disease. 1, 3 The Centers for Disease Control and Prevention reports that Class II obesity is associated with substantially higher rates of comorbidities compared to lower obesity classes. 3
Important Clinical Considerations
Waist circumference measurement is NOT necessary in patients with BMI ≥35 kg/m² because it is almost invariably elevated and adds no incremental risk information. 2
Treatment intensity should escalate with Class II obesity, warranting comprehensive lifestyle modification, pharmacotherapy consideration, and evaluation for potential bariatric surgery candidacy. 3
Bariatric surgery becomes a treatment option for patients with BMI ≥35 kg/m² when accompanied by weight-related complications, after non-surgical interventions have failed. 1