A recent study concludes that expressing very high BMIs relative to the Centers for Disease Control and Prevention (CDC) 95th percentile would be preferable to using BMI-for-age, particularly when assessing the effectiveness of interventions.
The researchers conducted a cross-sectional analyses of 8.7 million 2- to 4-year old children from 2008-2011 in the CDC’s Pediatric Nutrition Surveillance System to examine the associations among several BMI metrics (z-scores, percent of the 95th percentile and BMI minus 95th percentile).
Among children with severe obesity, BMIz levels could differ by more than 1 standard deviation among children who had very similar levels of BMI metrics due to differences in age or sex. The effective upper limit of BMIz values strongly influences the calculation of z-scores for children with severe obesity.
Check out our other blog post describing a study that found similar findings HERE.