How is severe pediatric obesity defined in relation to the 95th percentile?

• A. BMI above the 99th percentile.
• B. BMI above 110% of the 95th percentile.
• C. BMI at or above 120% of the 95th percentile.
• D. BMI at or above the 105th percentile.

Answer: (C)

Severe pediatric obesity is defined using a relative measure to growth norms because kids' bodies change with age and sex. The standard cut is a BMI that is at or above 120% of the 95th percentile for the child’s age and sex. This means the child’s BMI is 20% higher than the threshold that defines obesity (the 95th percentile), signaling a higher level of adiposity and risk.

For example, if the 95th percentile BMI for a certain age/sex is 22, then 120% of that is 26.4; a BMI of 26.4 or more would be considered severe obesity.

The other options don’t match this established threshold. Being above the 99th percentile is a high value, but it uses a percentile-based cut that isn’t the standard definition for severe obesity. The idea of 110% or 105th percentile doesn’t align with the 1.2× 95th-percentile rule used to define severe obesity.