title: Validity of self-reported weight and height of adolescents, its impact on classification into BMI-categories and the association with weighing behaviour.
abstract: This paper investigated the validity of self-reported height and weight of adolescents for the diagnosis of underweight, overweight and obesity and the influence of weighing behaviour on the accuracy. A total of 982 adolescents reported their height, weight, weighing behaviour and eating patterns in a questionnaire. Afterwards, their height and weight were measured and their Body Mass Index (BMI)-categories were determined using age- and gender-specific BMI cut-off points. Both girls and boys underreported their weight, whilst height was overestimated by girls and underestimated by boys. Cohen's d indicated that these misreportings were in fact trivial. The prevalence of underweight was overestimated when using the self-reported BMI for classification, whilst the prevalence of overweight and obesity was underestimated. Gender and educational level influenced the accuracy of the adolescents' self-reported BMI. Weighing behaviour only positively influenced the accuracy of the self-reported weight and not height or BMI. In summary, adolescents' self-reported weight and height cannot replace measured values to determine their BMI-category, and thus the latter are highly recommended when investigating underweight, overweight and obesity in adolescents.
authors.affiliation: Department of Public Health, Faculty of Medicine and Health Sciences, Ghent University, De Pintelaan 185, 2 blok A, B-9000 Ghent, Belgium. tineke.devriendt@ugent.be
authors.forename: Tineke
authors.initials: T
authors.lastname: De Vriendt
authors.forename: Inge
authors.initials: I
authors.lastname: Huybrechts
authors.forename: Charlene
authors.initials: C
authors.lastname: Ottevaere
authors.forename: Inge
authors.initials: I
authors.lastname: Van Trimpont
authors.forename: Stefaan
authors.initials: S
authors.lastname: De Henauw
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D002648:Child; D016001:Confidence Intervals; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity; D050177:Overweight; D015995:Prevalence; D012044:Regression Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D011795:Surveys and Questionnaires; D013851:Thinness