Introduction: Overweight and obesity prevalence has increased significantly over the past two decades, currently impacting greater than 60% of Australians. It is unclear if a social perception of a healthy weight has been obscured by the increase in prevalence and thus has become inconsistent with the medical definitions.
Methods: An electronic questionnaire was distributed via email and social media using the authors' informal networks. Australian adults were eligible to participate. Participants were asked to categorise their own body size using medically accepted words and previously published silhouettes, before identifying underweight, healthy weight, overweight or obesity in a series ofsilhouettes.
Results: Eight hundred six questionnaires were completed, a majority of participants had attained a high level of education and were employed female health professionals. Under half the studied population had a Body Mass Index (BMI) corresponding to overweight or obese categories (n = 349, 47%). Accuracy in self-perceived weight status using medicalised words was higher among respondents with BMI corresponding to the healthy weight category (n = 311, 85%) and overweight category (n = 133, 74%) than for respondents with BMI corresponding to obesity (n = 79, 45%) or underweight (n = 5, 31%). A majority of respondents were able to accurately self-perceive their weight status using silhouettes (n = 469, 70%). Females were significantly more likely to be accurate in their self-perception than males, using both medicalised words (p = < 0.001) and silhouettes (p = 0.045). Respondents with a BMI corresponding to the obese category were significantly more likely to be accurate with weight status self-perception using silhouettes than words (87% versus 46% respectively, p = < 0.001). Less than half (41%) of respondents accurately perceived silhouettes corresponding to an overweight BMI and less than one in ten respondents (9%) accurately perceived the lower limit of the silhouettes corresponding to an obese BMI.
Conclusions: Repondents were challenged to accurately perceive silhouettes corresponding to an obese BMI in themselves and others. Weight status misperception was more likely to exist among those with a BMI less than 18.5 or 30 or more (underweight BMI and obese BMI). Accuracy decreased as BMI increased. Respondents with a BMI in the obese category were significantly more likely to accurately self-perceive their weight status using silhouettes than medicalised words. Silhouettes may act as an effective visual cue in initiating weight related discussions.
Keywords: Body mass index; Obesity; Overweight; Social conditioning; Waist circumference; Weight perceptions.