Using BMI-for-age as a Screening Tool
Advantages to Using BMI-For-Age As a Screening Tool for Obesity, Overweight, Healthy Weight and Underweight
There are several advantages to using BMI-for-age to screen for obesity, overweight, healthy weight and underweight among children and teens.
BMI growth charts allow us to plot a child’s BMI on a chart. The pecentile lines on the growth chart indicate the BMI-for-age percentile ranking, which can be interpreted as the relative position of the child’s BMI to children of the same sex and age from the reference population.
BMI-for-age is the measure that can be used continuously for children and teens aged 2 to 20 years to screen for obesity, overweight, healthy weight, or underweight.
- BMI-for-age is not recommended for use as a screening measure in the United States before 2 years of age. For children younger than 2 years of age, BMI normative values are not available in the United States (Barlow, 2007), and BMI values at young ages have a weak association with adolescent or adult obesity (Whitaker et al., 1997; Guo et al., 1994).
- For children younger than 2 years old, the CDC recommends using the WHO growth charts to monitor growth (Grummer-Strawn, 2010). Plot weight-for-length values over time to monitor growth, and screen for high or low weight relative to length (Barlow, 2007).
- BMI can be used to track body size throughout the life cycle. Among children and teens, sex-specific BMI-for-age percentile is used, and among adults, BMI is used.
- The 2022 Extended BMI-for-age growth charts can be used to track BMI for children aged 2 to 20 years with very high BMIs above the 97th percentile. The 2000 CDC Growth Charts and their recommended use for children and adolescents without obesity have not changed.
- BMI-for-age relates to health risks.
- BMI-for-age correlates with clinical risk factors for cardiovascular disease, including high cholesterol and high blood pressure (Reilly et al. 2003). Freedman and colleagues used data from the Bogalusa Heart Study and found that approximately 70% of children who had obesity had at least one risk factor for cardiovascular disease, and 39% had two or more risk factors (Freedman et al., 2007).