While body mass index (BMI) correctly identifies adiposity in most youth with class 2 and 3 obesity, a relatively high degree of discordance was observed in youth with obesity and overweight, according to a recent study. Using dual energy x-ray absorptiometry (DXA) data from the National Health and Nutrition Examination Survey 1999 to 2006, 10,465 youth aged 8 to 20 years were studied for the analysis. Researchers found:
• Nearly all youth with class 3 obesity and a high proportion of those with class 2 obesity had excess adiposity.
• There was significant discordance between BMI characterization and DXA-derived excess adiposity among youth with class 1 obesity or overweight.
• Cardiometabolic risk factors are increased in the presence of excess adiposity, regardless of cutpoint used.
Citation: Ryder JR, Kaizer AM, Rudser KD, Daniels SR, Kelly AS. Utility of body mass index in identifying excess adiposity in youth across the obesity spectrum. [Published online ahead of print August 2, 2016]. J Pediatr. doi:10.1016/j.jpeds.2016.06.059.
1. Odde JJ, et al. Body mass index as a predictor of percent fat in college athletes and nonathletes. Med Sci Sports Exerc. 2007;39(3):403-409.
2. Romero-Corral A, Somers VK, Sierra-Johnson J, et al. Accuracy of body mass index in diagnosing obesity in the adult general population. Int J Obes (Lond). 2008;32(6):959–966. doi:10.1038/ijo.2008.11.