We're telling porkies about our weight
Wednesday, 13 December 2006
Australia's obesity epidemic may be far worse than realised, with an Adelaide study revealing that most people under-estimate their weight by nearly two kilograms.
Using self-reported figures it is estimated that 56% of Australians are overweight, yet the figure is more likely to be 65.3% if clinical measures are used, according to medical researchers from the University of Adelaide and SA Department of Health.
The findings result from a study of more than 1500 adults in Adelaide's north-west region who answered a telephone survey and followed up with actual clinical tests, revealing the discrepancies.
Weight isn't the only anomaly, however. On average, adults over-estimate their height by 1.4cm, particularly those aged over 65 years.
Using self-reported data, 19.1% of the respondents fell into the obese category, compared with 26.3% from the clinical measurements - a difference of more than 7%.
Associate Professor Anne Taylor from the University of Adelaide and the SA Department of Health says the findings underline the importance of valid and reliable data to draw accurate conclusions about the nation's health.
"Self-reported data from population surveys are, in many instances, the primary source of information for health planners. It is crucial the data is correct because it is important for planning strategies and services.
"Some of the disparity between self-report and clinical measures for height and weight is due to the rounding effect. Adults, especially women, tend to round down their weight, and older people do not account for loss of height associated with ageing," Associate Professor Taylor says.
The anomalies are consistent with other major studies in Europe, the United Kingdom and the United States.