For example if your BMI is 24 and is 80th percentile for your age, that means your BMI is 80th compared to 100 typical kids your age and sex. Because BMI percentile is related to health risks. And most importantly, the overweight and underweight BMI percentile values are the same for all ages. Therefore, if your BMI is in either the top or bottom 5 percent, you have health risks due to your weight. Six out of ten children and teens with a BMI above the 95th percentile have at least one risk factor for cardiovascular disease while 2 out of 10 have two or more risk factors for cardiovascular disease.
Overweight children are likely to become overweight adults.
Guidelines of the Expert Committee on Overweight in Children and Adolescents.