Self-reported BMI bias estimates increasing due to weight bias, not weight loss

The gap between obesity levels measured by self-reported height and weight and obesity recorded by measured height and weight is increasing. This is due to an increasing bias in self-reported weight, according to research published January 23 in the open access journal PLOS ONE by Frances Shiely and colleagues from University College of Cork, Ireland.

BMI is a ratio of height and used clinically to assess whether an individual's weight is in a healthy range. Previous studies have shown that people tend to over-estimate their own height and under-estimate their weight and it is generally assumed that both are responsible for under-estimation of self-reported BMI. The authors of this study have shown in previous work that under-estimation of BMI is increasing over time. Here, they assess whether this increasing inaccuracy is due to changing biases in self-reported height, weight, or both, using data from a representative sample of Irish adults.

The researchers found that the in self-reported height has remained stable over the last ten years regardless of gender, age or clinical BMI category. However, biases in self-reported weight have increased over time for both genders and in all age groups. The bias towards reporting a lower weight is most notable in those who are obese.

The authors state that knowing why self-reported scores are decreasing while clinically measured BMIs are not "brings us one step closer to accurately estimating true obesity levels in the population."

More information: Shiely F, Hayes K, Perry IJ, Kelleher CC (2013) Height and Weight Bias: The Influence of Time. PLoS ONE 8(1): e54386. doi:10.1371/journal.pone.0054386

Related Stories

Most people fudge numbers on weight and height surveys

date Jan 27, 2012

When people in the U.S. are asked to provide their weight for research surveys, they underestimate their weight and overestimate their height, despite numerous public reports about increasing rates of obesity. ...

Rethinking body mass index for assessing cancer risk

date Nov 08, 2012

A study by researchers at Albert Einstein College of Medicine of Yeshiva University suggests that body mass index (BMI)—the most commonly used weight-for-height formula for estimating fatness—may not be the best measure ...

Recommended for you

Cost of lifestyle advice during pregnancy is worth it

date 19 hours ago

Research from the University of Adelaide shows that the additional cost of providing  one-on-one lifestyle advice to overweight and obese women during pregnancy is offset by improved outcomes at birth.

Team develops anti-obesity treatment in animal models

date Mar 26, 2015

Researchers from the Spanish National Cancer Research Centre (CNIO) have shown that partial pharmacological inhibition of the PI3K enzyme in obese mice and monkeys reduces body weight and physiological manifestations ...

Binge eating linked to comorbidities in obese adults

date Mar 25, 2015

(HealthDay)—For obese adults, binge eating disorder (BED) may be associated with specific medical comorbidities, according to a study published online March 16 in the International Journal of Eating Di ...

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.