The Average Bmi For A Teenager

Avoid the temptation to lump teens in with adults when it comes to body mass index (BMI). While teens and adults are often comparable in size, an average BMI for an adult may not be the same as the average for a teen. Factors such as age and gender require the use of a separate system to categorize BMI in teenagers. The health consequences and long-term significance of having an abnormal BMI during developmental years are different as well.

Function

BMI is determined by a mathematical formula. This formula uses your height and weight to calculate the amount of body fat you have. The simplicity and reliability of BMI calculation has made it a standard screening tool. However, since body fat is not measured directly, there are occasional inaccuracies. For instance, false high BMIs are sometimes noted in athletes with a large amount of muscle mass.

BMI Categories

BMI classifications for teens are defined by percentiles using the BMI-for-age growth chart. These charts are available from the Centers for Disease Control and Prevention (CDC). A BMI less than the fifth percentile indicates you are underweight. If your BMI falls between the fifth and 84th percentile, you are within the normal range. A BMI in the 85th percentile and above indicates that you are overweight or obese. The CDC also provides an online calculator designed specifically for teens to assist you in determining which category you fall into.

Significance

Health professionals utilize BMI to determine the risk an individual has of developing a weight-related disease. Teens with a BMI in the overweight and obese range have higher rates of conditions such as asthma, early onset puberty, metabolic syndrome (insulin resistance) and menstrual abnormalities. Development of conditions typically associated with adult obesity, such as joint pain, diabetes and cardiovascular disease, is more likely as well. A BMI in the average, or healthy range, helps you avoid these increased risks.

BMI Statistics

The number of teens with a healthy BMI has declined over the past 30 years. The majority of teens still have an average BMI, however, in spite of the obesity epidemic. 2007 data from the National Survey of Children's Health indicated that approximately 63 percent of children age 10 to 17 years had a healthy BMI. About 32 percent were overweight or obese, while around 5 percent were underweight.

Considerations

If your BMI is above average, now is the time to bring it into the normal range. According to calculations from HealthyChildren.org, if you finish adolescence in the obese category, you only have a 5 percent chance of achieving and maintaining a healthy weight in your adult life. Consult with your health care provider and search for resources to help you make needed lifestyle changes. Nutrition and activity information, including personalized plans, are available at the U.S. Department of Agriculture's MyPyramid website.