What is the definition of obesity in children?

• A. BMI greater than the 95th percentile for age and sex.
• B. BMI between the 25th and 50th percentile.
• C. Height greater than the 95th percentile.
• D. BMI less than the 5th percentile.

Answer: (A)

In pediatrics, obesity is defined using body mass index adjusted for age and sex. BMI is calculated from weight and height, but for children the result is interpreted with growth charts to find the percentile for the child’s age and sex. Obesity is defined as a BMI at or above the 95th percentile for age and sex. This threshold accounts for how children grow and vary normally, providing a standardized standard. The other scenarios don’t describe obesity: a BMI in the middle ranges indicates average weight, a height above the 95th percentile is just tall stature, and a BMI below the 5th percentile indicates underweight. So the defining criterion is a BMI at or above the 95th percentile for age and sex.