How to Interpret Percentiles
Four percentile ranges exist, and each is assigned a weight status category. Underweight is less than the 5th percentile, while overweight is from the 85th to the 95th percentile. A teenager is considered obese if his weight is at the 95th percentile or above. A healthy weight is anywhere from the 5th percentile to the 85th percentile.
Adults vs. Teens
In adults, a healthy BMI falls between 18.5 and 25. But this range does not apply to teens, as the amount of body fat changes with age, and it differs between girls and boys. For this reason, the percentile is used, which takes into account a teenager’s age and sex. For example, a 10-year-old boy with a BMI of 23 would be classified as obese, but a 15-year-old of the same BMI is in the healthy weight category.
Learning More About Healthy Weight
Parents often want to know what their child should weigh. Healthy weight ranges are not provided for teens, due to changes in height that occur as a child grows. Because of differences in the onset of puberty between boys and girls, these changes are sex-specific. It is therefore important to determine the percentile that applies to your teen. The CDC recommends that teenagers whose BMI percentile falls above the range considered healthy undergo additional testing to determine body fat. This may include measurements of skinfold thickness and assessments of diet and physical activity. For further information, talk to your doctor.