Aim: To explore the relationship between self-reported weight and height to actual weight and height in a cross-sectional nationally representative sample of young adolescents.
Methods: Weights and heights were obtained on 1932 adolescents aged 12-16 y enrolled in the NHANES III study. Self-reported weights and heights were available on 1657 of the adolescents (86%).
Results: Correlation between self-reported weight and actual weight ranged between 0.87 and 0.94, depending on gender or race. However, self-reported weights were significantly lower than measured weights among girls, compared to boys (P < 0.001). Correlation between self-reported height and actual height ranged from 0.82-0.91. There were no differences in the accuracy of self-reported heights among boys and girls or racial groups. Differences between actual weight and self-reported weight were significantly greater for obese children compared with non-obese children (P < 0.001). Nevertheless, the use of self-reported weight and height resulted in the correct classification of weight status in 94% of children. As a result, small differences in self-reported weights and heights had no impact in assessing obesity related morbidities.
Conclusion: Influences of gender and racial biases in reporting of weight and height were relatively small. Self-reported heights and weights were extremely reliable for the predicting obesity related morbidities and behaviours.