How often should BMI be calculated and plotted for children and adolescents at risk of overweight or obesity?

• A. Monthly
• B. Annually
• C. Weekly
• D. Daily

Answer: (B)

Tracking BMI over time is about watching how a child’s weight status changes as they grow, not reacting to a single measurement. The best interval for routine BMI calculation and plotting in children and adolescents at risk of overweight or obesity is annually. This cadence fits with standard well‑child visits and lets you see meaningful, long‑term trends in BMI percentile, while reducing the influence of short‑term fluctuation or measurement error. Measuring more often—monthly, weekly, or daily—tends to capture noise rather than true trajectory and can be unnecessarily burdensome. If a child shows unusually rapid weight gain or other concerns, more frequent monitoring can be considered, but for routine at‑risk monitoring, annual assessment is appropriate.