Assessment of adolescent weight status: Similarities and differences between CDC, IOTF, and WHO references

The research sought to determine the reliability of assessing adolescents' weight status based on three standard criteria, Centers for Disease Control and Prevention (CDC) growth charts, International Obesity Task Force (IOTF) standards, and the World Health Organization (WHO) growth references.

Data from the NEXT Generation Health Study US 10th grade cohort (n=2323, mean age=16.19years) starting in 2009 were used. Kappa statistics assessed agreement of assignment to weight categories. Associations of weight status with perceived body image, weight control intention, and general health were examined using linear regressions accounting for complex survey design.

Kappas across weight status criteria were≥.89 and agreement exceeded 90% in all analyses. For all three criteria, overweight and obese participants, compared to normal weight, were significantly more likely to indicate fatter body image, higher weight control intention, and poorer general health; small differences in the regression coefficients by classification method were observed.

The three criteria of weight status classifications substantially agreed. Associations of weight status with selected health correlates were similar regardless of the methods. Thus, the three classifications can be considered comparable for most research and practice purposes.