Does Your Child Have a Healthy BMI? Calculate it Here
Parents often ask me if the BMI applies to kids. It does, but I tell them to use it with caution as their kids are still growing. However, I also mention studies indicate that a child with a high BMI is at a greater risk of becoming an overweight or obese adult.
Calculating BMI: Divide the individual's weight (in kilograms) by their height (in metres), squared. For adults, as soon as you determine the BMI, you simply refer to the following categories:
Underweight - 18.5
For kids, you have to go one step further and refer to the percentile charts created by the Centre for Disease Control and Prevention (CDC). These charts take into consideration your child's gender and age (they also have an online BMI calculator). Here's an example of my six-year-old son, Ryan:
23.63 kg (52 lbs) / 1.27m x 1.27m (4 foot, 2 inches), which works out to 23.63 kg / 1.61
BMI = 14.68 kg/m squared
By referring to the appropriate chart for boys aged 2-20 years old, Ryan's BMI of 14.68 in relation to other six-year-old boys places him in the 10th percentile. Based on the following categories, he is at a "healthy weight."
Underweight - BMI less than the 5th percentile
Healthy Weight - BMI 5th percentile up to the 85th percentile
At Risk of Overweight - BMI 85th to less than the 95th percentile
Overweight - BMI greater than or equal to the 95th percentile
What You Should Know
Keep in mind that the BMI does not consider the bone or muscle mass of your child. It assumes extra weight is fat. This is why I recommend measuring often and looking for a pattern or trend. A child with a heavy build who may be very muscular and athletic will probably measure at a higher percentile.
What Should You Do?
Regardless of your child's BMI, it is important that you encourage a lifestyle conducive to maintaining a healthy weight. This includes exercising at least 60 minutes a day, eating a well-balanced diet, rich in fruits and vegetables, limiting television time and getting a lot of sleep.
Reggie Reyes is a certified kinesiologist and personal trainer. He is the president and founder of pt4kids a company that creates specialized training programs for kids all ages and fitness levels.