Which percentile is used as reference for obesity classifications?

• A. 95th percentile
• B. 50th percentile
• C. 75th percentile
• D. 99th percentile

Answer: (A)

In children, obesity is determined by comparing their BMI to age- and sex-specific growth charts. The reference point for classifying obesity is the top category on these charts, meaning the child’s BMI is higher than most peers of the same age and sex. This high placement on the chart signals excess adiposity with associated health risks, which is why it’s the standard cutoff used to label obesity.

Understanding the contrast helps: there are lower thresholds that define overweight and normal weight on the same charts, and those categories do not indicate obesity. Some guidelines also describe very high BMI values as a severe or extreme form, but the usual obesity cutoff is defined by that top category on the BMI-for-age chart.