Class III obesity is defined as which range relative to the 95th percentile?

• A. 95th to <120% of 95th percentile
• B. 120% to <140% of 95th percentile
• C. ≥140% of 95th percentile
• D. 85% to 95th percentile

Answer: (C)

Pediatric obesity staging uses the BMI percentile for age and sex, but expressed as a multiple of the 95th percentile. As BMI rises beyond the 95th percentile, higher obesity classes are defined by multiplying that 95th percentile by 1.2 and 1.4. Class III obesity is the category where the BMI is at least 1.4 times the 95th percentile. In other words, the cutoff is 140% of the 95th percentile. For example, if the 95th percentile for a given age/sex is 20 kg/m^2, a BMI of 28 kg/m^2 or higher would be class III obesity. The ranges 95th to 120% and 120% to 140% correspond to class I and class II obesity, respectively, while a BMI between the 85th and 95th percentiles is considered overweight, not obese.