Schools in your area may be assessing students’ health, collecting BMIs, or providing nutrition and physical activity education. What does all this mean and why is this becoming more common?
So what exactly is a BMI?
BMI, or Body Mass Index, is a method to measure body mass based on a person’s weight and height. Weight and height are plugged into a standard formula which can then be compared to a range or norm. The Center for Disease Control states that a BMI calculated result is a reliable body fatness indicator for most teens and children. Although BMI does not measure body fat directly, it can be used as an indirect measure. An example of a direct measure of body fat would be underwater weighing or the Bod Pod (air displacement plethysmography). BMI is useful as a screening tool to help identify weight concerns and implement prevention education.
After the BMI number is obtained, the number is plotted on the boy’s or girl’s BMI-for-age growth chart. A percentile ranking is determined and this percentile is used to assess growth patterns of the individual child. Comparison is done with children of the same sex and age. Four different categories of weight status are used to categorize the child or teen. These include underweight, healthy weight, overweight, and obese. The American Academy of Pediatrics and the Center for Disease Control recommend the use of BMI to screen children beginning at the age of 2.
Why BMI in Schools?
BMIs in schools vary per state and district. According to a comprehensive study in Preventing Chronic Disease, 20 states were requiring BMI or body composition screening with 9 additional states recommending the screening as of 2010. BMIs are designed to provide information and initiate conversations regarding ways to make healthy nutrition and physical activity choices.
Many factors must be taken into consideration with BMI and it is crucial to remember that BMI calculations are not perfect. Age and gender are important to consider in this assessment. The healthy level of the child or teen varies for age month by month and as his or her height increases.
Expert organizations still recommend using BMI surveillance as an effective screening tool. Although there needs to be more studies evaluating the effectiveness of these programs, with the proper use of guidelines and resources, BMI screening could become a more common, accepted, and useful tool in assessing and triggering interventions for obesity among children.
The BMI can be most useful when it is considered one additional tool in the toolbox. It is not the only tool, but one that can be a starting point for healthy conversations. BMI’s may be effective in evaluating the effectiveness of health programs.
Knowledge is power toward healthy behaviors.
Nihiser AJ, Lee SM, Wechsler H, McKenna M, Odom E, Reinold C, Thompson D, Grummer-Strawn L. BMI Measurement in Schools. Journal of the American Academy of Pediatrics. 2009. 124;589:597.
Written by: Shannon Erskine, Dietetic Intern/ Liz Smith, MS, RD, LDN, Ohio State University Extension, NE Regional Program Specialist, SNAP-ED, firstname.lastname@example.org.
Reviewed by: Beth Stefura M Ed, RD, LD, Ohio State University Extension, Family and Consumer Sciences Educator, Mahoning County, Stefura.email@example.com.