The ABCs of BMI
When is the last time you heard (or said) something like this: “Oh, it’s just baby fat. They’ll grow out of it.” As parents, we need to understand that the growing weight problem in our kids can be very real, and serious.
Experts speculate that because of increasing obesity rates, our kids may be the first generation to be less healthy and have a shorter life expectancy than their parents. The Centers for Disease Control and Prevention reported that in 2012 more than one third of children and adolescents were overweight or obese.
How do we know where to draw the line between a little extra baby fat and a potential health risk? Physicians use a tool called Body Mass Index (BMI) to estimate how much body fat a person has.
What is BMI?
Body Mass Index is calculated using your child’s height and weight. The number obtained is then plotted on a growth chart and this allows your physician to compare your child’s growth with other children in the United States based on your child’s age and gender. When they do so, they can usually determine what percentile your child falls on the growth chart.
A child with a BMI percentile on the growth chart based on their age and gender can be in one of the following categories
- Below the 5th percentile is underweight
- Between the 5th and 84th percentile is normal weight
- From the 85th to the 94th is overweight
- Above the 95th is obese
It is important to note that BMI is only one tool used to screen for a child’s growth and many other factors play a role in your child’s overall health. For some very muscular individuals, the BMI may not accurately access their body fat.
What does it mean for my child?
Overweight children are much more likely to become obese adults. They also have a higher risk for heart disease, high blood pressure, Type 2 diabetes and many other medical complications. Overweight kids suffer from non-medical issues, as well, including low self-esteem, poor performance in school and bullying.
How do I find my child’s BMI?
There is a simple formula for calculating your child’s BMI:
- Step 1: Multiply your child’s weight (in pounds) by 703.
- Step 2: Convert your child’s height to inches and multiply that number by itself.
- Step 3: Divide the number you get in Step 1 by the number you get in Step 2.
For example, if your child is 4’2’’ (50 inches) and weighs 100 pounds:
- 100 multiplied by 703 = 70300.
- 50 multiplied by 50 = 2500.
- 70300 divided by 2500 results in a BMI of 28.12. This child is overweight.
What can I do if my child is overweight or obese?
It is important to remember that there is no quick fix to obesity. The good news is that very little changes can make a big difference over time. There are many reliable resources to help your child and family with implementing a healthy lifestyle. Here are some websites that have great tips:
Please note: Children and teens should not start a weight loss plan without first consulting healthcare professionals.
Your primary care physician’s office is an excellent place to start. The team of experts in the Center for Healthy Weight and Nutrition at Nationwide Children’s Hospital can also help your child make the diet, exercise and lifestyle changes necessary to achieve their weight loss goals.
For adolescents who are unable to control their weight through diet and exercise alone, the bariatric surgery program at Nationwide Children’s may be an option. Click here to learn more about weight loss surgery, or find out if you might be a candidate for bariatric surgery by answering seven simple questions