The results in Table 1 show a substantial amount of misclassification of the BMI based on self-reported height and weight (self-reported BMI) compared with the BMI based on measured height and weight (measured BMI). More than 43% of respondents classified as "underweight" and 16% of respondents classified as "overweight" based on their measured BMI were classified as "normal weight" using the self-reported BMI. In addition, 19% of respondents classified as "obese" using measured BMI were misclassified as "overweight" using self-reported BMI. The general trend is for classification errors to be larger in the extreme (over- or underweight) categories. Sensitivity values (the proportions of overweight or obese persons according to physical measurement, who are classified as overweight or obese according to their self-reported measures) are 91.4% for overweight or more and 83.3% for the obesity classification. The corresponding positive predictive values (the proportion of self-reported 'overweight' or 'obese' persons who actually are overweight or obese based on measured height and weight) are 95.8% and 93.9%, respectively. However, a closer look at the misclassifications reveals that the majority of the misclassified cases
