Four-Year-Old with BMI Out of Range — Is It Obesity or Not?

My son is tall and sturdy. At every school checkup, his BMI is out of range. I finally dug into why.

Children's BMI is calculated differently from adults'. The CDC and WHO have specific growth charts that account for age and sex. What matters is the BMI percentile, not the raw number.

For children: Under 5th percentile is underweight, 5th-85th is healthy, 85th-95th is overweight, over 95th is obese. My son was at the 87th percentile — barely overweight. His pediatrician wasn't concerned.

Kids also grow in spurts. Sometimes BMI jumps right before a growth spurt. The timing of a checkup can catch them at the wrong moment.

If your child's BMI is above the 85th percentile, don't panic. Don't put them on a diet. Focus on healthy habits — more vegetables, less screen time, more outdoor play. A single data point isn't a diagnosis.