Validity of self-reported weight and height by high school students in the city of Cordoba city

Objective: To examine the validity of self-reported weight and height versus their direct measurement for the diagnosis of overweight and obesity in adolescent students in the city of Cordoba. Methods: A cross-sectional pilot study was carried out with 552 adolescents attending 1st to 3rd year at three high schools. Weight and height were collected through a self-administered questionnaire and were measured directly by trained staff. We calculated average differences for weight, height and body mass index (BMI =kg/cm2), and sensitivity-specificity and concordance coefficient (k) were analyzed for overweight and obesity diagnosis. Results: Average self-reported weight was underestimated compared to measured weight, but not self-reported height. Declared BMI was underestimated -0.85 kg/cm2 in women and -0.26 kg/cm2 in men. The sensitivity-specificity was 61%-89% to detect overweight, and 80%-98% to diagnose obesity. Conclusion: The self-reported weight and height underestimated the prevalence of overweight but not of obesity.