1. What is BMI-for-age?

BMI-for-age is a measure that accounts for a child's age and sex when assessing their body mass index (BMI). For children, BMI is interpreted relative to other children of the same age and sex because their body composition changes as they grow.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

• \( weight \) — Body weight in kilograms
• \( height \) — Height in meters

Explanation: The result is then plotted on CDC growth charts to determine the percentile for age and sex.

3. Importance of BMI-for-age

Details: BMI-for-age is the recommended measure for screening overweight and obesity in children and teens. It helps identify potential weight problems that may lead to health issues.

4. Using the Calculator

Tips: Enter weight in kilograms, height in meters, age in years (2-19), and select gender. All values must be valid (weight > 0, height > 0, age between 2-19).

5. Frequently Asked Questions (FAQ)

Q1: How is BMI-for-age interpreted?
A: The CDC defines weight categories as: Underweight (<5th percentile), Healthy weight (5th-85th percentile), Overweight (85th-95th percentile), Obese (≥95th percentile).

Q2: Why use BMI-for-age instead of regular BMI?
A: Children's body fat changes with age and differs between boys and girls. BMI-for-age accounts for these normal developmental differences.

Q3: What are the limitations of BMI-for-age?
A: It doesn't measure body fat directly and may misclassify muscular children. It's a screening tool, not a diagnostic tool.

Q4: How often should children's BMI be checked?
A: The American Academy of Pediatrics recommends annual BMI screening for all children aged 2 years and older.

Q5: Where can I find CDC growth charts?
A: CDC growth charts are available at: https://www.cdc.gov/growthcharts/