BMI or Body Mass Index estimates how much fat you have in your body. It is calculated based on weight and height measurements. Using these values, how can one know if their child is underweight, normal weight, overweight, or obese?
Here are the formulas to calculate the BMI:
1. Kg/m2 – divide weight (in kilograms) by height squared (in meters)
2. (Lbs/in2) x 703 – divide weight (in pounds) by height squared (in inches) and multiply the quotient by 703 (standard conversion factor).
For adults, the result from the calculation above is evaluated using standard weight-status categories. The World Health Organization (WHO) regards a BMI greater than 25 as overweight while those above a BMI of 30 are considered obese.
Using BMI to evaluate a child or teenager’s weight status is, however, a different story. For kids, you start exactly with the same formula stated above but instead of checking it with the standard weight-status categories, you compare the resulting BMI with typical values of kids coming from the same age group.
According to the US Centers for Disease Control and Prevention website (www.cdc.gov), children’s BMI results fall into 1 of 4 possible categories:
● If BMI is below the 5th percentile = underweight
● If BMI is equal to the 5th and less than the 85th percentile = normal weight
● If BMI is equal to the 85th or any value less than the 95th percentile = overweight
● If BMI is greater than or equal to the 95th percentile = obese
BMI may be quite difficult to interpret once a child has entered the puberty stage because this is the time when children undergo periods of growth spurts. Remember that BMI is only a good indicator of a child’s weight status but it isn’t an accurate measurement of body fat. If you want to find out whether your child or teen is indeed overweight or not, it is best to make an appointment with your pediatrician or family doctor. Your doctor can thoroughly assess your child’s eating habits as well as his daily activities, and test him for medical conditions associated with obesity.