How is pediatric BMI percentile interpreted?

• A. Compare BMI to adult fixed cutoffs.
• B. Use BMI alone without growth charts.
• C. Plot BMI on age- and sex-specific growth charts to determine percentile; classify as underweight, healthy weight, overweight, or obese.
• D. Ignore growth charts.

Answer: (C)

In children, BMI must be interpreted in context of growth: you determine where a child falls on age- and sex-specific growth charts rather than using adult fixed cutoffs. First, calculate the BMI and then plot it on the chart that matches the child’s age and sex. The chart gives a percentile that shows how the child’s BMI compares with peers. Based on that percentile, weight status is summarized as underweight (<5th percentile), healthy weight (5th to <85th percentile), overweight (85th to <95th percentile), or obese (≥95th percentile). This approach acknowledges that kids grow at different rates and that BMI needs context to indicate true risk. BMI by itself isn’t a diagnosis; it’s a screening tool that should be interpreted with growth history and other factors.