Waistlines are expanding, and it's not just true for adults. According to the Centers for Disease Control and Prevention, 18.1 percent of adolescents aged 12 to 19 years old were considered obese in 2007 to 2008, up from five percent from 1976 to 1980. It can be difficult to determine the proper weight for teenagers because their bodies are constantly changing and growing, but the CDC uses the body mass index as a general indicator of healthy weight.
About BMI
BMI is simply a relationship between height and weight that can give you a general idea of your place in the obesity scale. Teens shouldn't use the same charts as adults, because although the formula is the same, age and gender are also taken into account until you're 19 years old, when you have what is considered an adult body composition. Until then, different amounts of body fat are considered appropriate at different ages.
Finding Your BMI
Online calculators at the CDC or Keep Kids Healthy websites make it simple to find your BMI, or you can do it yourself. Measure your height to the nearest 1/8 inch, and your weight to the nearest 1/4 pound. Square your height in inches, and multiply it by 703. Divide your weight in pounds by this number. The result is used to find your BMI percentile.
Percentiles
Visit the CDC website to download a Clinical Growth chart to determine where you are on the scale, or check a teen BMI chart next time you are at your doctor's office. To use the chart, find your age on the bottom line and your BMI on the vertical line. The point where they meet will fall between two wavy lines, which will tell you your percentile. For example, a 16-year old girl with a BMI of 23 falls just outside the 75th percentile, which is considered well within the healthy range. On an adult BMI scale, she would be within two point of being classified as overweight, but the children's BMI scale takes her age into account.
Categories
If you fall between the fifth and 85th percentile, you are at a healthy weight for your age. If you are below that range, you are underweight. If you are between the 85 and 95 percentile, you are considered overweight, and if you are at or above the 95 percentile, you are considered obese. The BMI is not a diagnostic tool; it does not take body fat percentage into account. But if your BMI is in a high percentile, it is a sign that it's time to talk to your doctor about your weight and your eating habits.
References
- Centers for Disease Control and Prevention: About BMI for Children and Teens
- Centers for Disease Control and Prevention: BMI Percentile Calculator for Child and Teen English Version
- Centers for Disease Control and Prevention: Prevalence of Obesity Among Children and Adolescents: United States, Trends 1963-1965 Through 2007-2008
- Centers for Disease Control and Prevention: BMI Formula for Children and Teens
- Centers for Disease Control and Prevention: Clinical Growth Charts
- Keep Kids Healthy: BMI Calculator
Member Comments