Comparison of self-reported and measured height and weight: implications for obesity research among young adults.
BACKGROUND
The use of self-reported data in epidemiological surveys leads to misclassification of the prevalence of obesity as the participants overestimate or underestimate height, weight and/or both. Such misclassifications vary according to gender, age, status and ethnicity.


OBJECTIVE
To estimate on a sample of youth of both sexes (1) the difference between self-reported data and measured height and weight and (2) the extent of misclassification of BMI deriving from such differences.


METHODS
Self-reporting in questionnaires and subsequent measurements of height and weight conducted by trained personnel. The mean values and the BMIs were calculated.


RESULTS
Both sexes overestimate height (2.1 and 2.8cm for males and females, respectively), and underestimate weight (1.5 and 1.9kg for males and females, respectively). Consequently the BMI is underestimated (1.1 and 1.5 points for males and females, respectively). The classification of BMI from self-reported data shows underestimation of overweight in both sexes (8 percentage points) and of obese males (3.3 percentage points), an overestimation of normal weight (12.2 and 4.3 percentage points for males and females, respectively) and an excessive underweight in the girls (4.3 percentage points).


CONCLUSIONS
There is a difference between self-reported and measured data and self-reported biases are reflected in the classification of the participants in the 4 categories of BMI.
Danubio
Maria Enrica
ME
Faculty of Human Movement and Sport Sciences, University of L'Aquila, Italy. marica.danubio@cc.univaq.it
Miranda
Gaetano
G
Vinciguerra
Maria Giulia
MG
Vecchi
Elvira
E
Rufo
Fabrizio
F
D000328:Adult; D000886:Anthropometry; D015982:Bias; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D003431:Cross-Cultural Comparison; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D009765:Obesity / Q000453:epidemiology* / Q000209:etiology; D015203:Reproducibility of Results; D012650:Self Disclosure; D011795:Surveys and Questionnaires