Embarrassed about BMI?Thursday, February 12, 2009
In adults, we know that self-reported height and weight are notoriously inaccurate – men tend to over-report height, women tend to under-report weight.
But what about kids, especially those who fail to divulge their height or weight in school surveys?
This interesting question was now studied by Helena Fonseca and colleagues from the Hospital de Santa Maria, Lisboa, Portugal, in a paper just published in Arch Dis Child.
Fonseca and colleagues examined the emotional, behavioural and social correlates of missing values for body mass index (BMI) in a nationally representative sample of 6131 Portuguese public school students aged 11-16 years who participated in a 2002 survey.
In this sample, 661 (10.8%) did not report their weight and/or height on the questionnaire.
While gender was not associated with missing BMI values, younger age, sedentary lifestyle, poor body satisfaction, absence of father, lack of friends of the opposite sex and poor perception of academic achievement all predicted missing BMI.
Clearly, these findings suggest that kids with poorer body image, poorer health behaviours and poorer social networks are more likely to skip the height and weight questions on surveys.
The results of this study should certainly remind us of the tremendous sensitivities about obtaining and reporting these measures in kids (think of the potential negative impact of any school-based height-weight measurement programs, if not conducted with the utmost sensitivity; also imagine the potentially devastating effect of “BMI Report cards”).