The U.S. Centers for Disease Control and Prevention plots measurements of children according to percentiles, or how they compare to other children of the same gender and age. Although one child is in a top percentile and another is at the bottom, both children can be perfectly healthy and growing just as they should. When judging your 10-year-old child's height and weight, taking all of the considerations into mind is key to getting a full picture.
The CDC created the growth charts used by most physicians in the United States and updates them regularly, most recently in 2000. A growth chart measures where a child of a particular age ranks in terms of weight, height and body mass index, or BMI. It is measured as a percentile. An average child would measure somewhere in the 50th percentile in these three categories. For example, a 10-year-old girl who is 4 feet 7 inches tall and weights 74 lbs. would be in the 53rd percentile for weight and the 58th percentile for height – about average. This means that 53 percent of 10-year-old girls weigh less than she and 58 percent of 10-year-old girls are shorter than she is.
Body Mass Index
The Body Mass Index -- or BMI -- is a number derived from correlating weight and height and is also measured on the CDC's growth charts. In general, it reflects how much fat a child is carrying on her frame. Sometimes, however, it can be misleading. For instance, an athletic African American teenager can have a very high BMI due to muscle mass rather than fat. If you want to determine your child's BMI, there are calculators available on the Internet, into which you can plug applicable information, such your child's age, weight, height and gender. A 10-year-old girl who is 4 feet 7 inches tall and weights 74 lbs. would have a BMI of 17.2. This puts her in the 56th percentile for BMI, which is healthy.
Implications of BMIs
The higher a child's BMI, the more likely it is that he is overweight. According to the CDC, a 10-year-old boy who is 4 feet 7 inches tall and weighs 99 lbs. would have a BMI of 23 and would be obese. He falls into the 95th percentile on the growth chart, and 95 percent of male children his same age have a lower BMI than he. A healthy BMI for a 10-year-old boy would be approximately 18, same as for a girl.
Potential Warning Signs
A very high BMI can signal a weight issue for your child and might be a problem in and of itself. However, with weight and height, physicians are not necessarily concerned with how a child compares with other children, but how he compares with himself. Children's growth will generally follow a pattern. A cause for concern might be if his percentiles for height and weight are falling consistently over time. Alternately, his height and weight percentiles might not increase at the same pace as he grows older. If he is gaining weight faster than he is growing taller, this might also be a reason for concern, especially if his BMI is rising accordingly.