We investigated the implications of underestimating self-perceived weight-status among Hong Kong (HK) Chinese adults on the prevalence of obesity-associated diseases

A telephone survey targeting HK Chinese adults was performed in early 2025 with randomly selected phone numbers generated from a territory-wide phone database from HK Office of the Communications Authority. Clinical characteristics, knowledge, and attitudes on weight-status and weight reduction were assessed. Respondents were asked to subjectively classify their weight-status as “underweight”, “normal-weight”, “overweight”, or “obese”. Their actual weight-status was determined by body mass index (BMI) calculated from their reported body weight and height. Comparisons were made between self-perceived and actual weight-status according to the WHO classifications. Discrepancies were categorized into “under-estimation”, “accurate-estimation”, and “over-estimation” of weight-status

A total of 1005 subjects (male = 515, female = 490) were surveyed, with mean weight  SD of 70.5812.37 kg (BMI = 24.133.83 kg/m2) for male and 56.109.06 kg (BMI = 22.423.54 kg/m2) for female. “Under-estimation”, “accurate-estimation”, and “over-estimation” of weight-status were 33.2%, 51.7%, 11.3%, respectively. Of the “under-estimation” group, 70.3% aged ≥40 and 44.4 % attained secondary school or below education. Of the “over-estimation” group, 59.6% aged <40 and 62.5% attained college or above education. More male underestimated their weight-status than female (69.8% vs 30.2%) while more female overestimated than male (79.8% v.s. 20.2%). Compared with others, the “over-estimation” group relied more on subjective personal feelings (36.0%) to guide their self-perception of weight-status, and their motivations for weight reduction were changing body shape 45.6% and boosting self-confidence 28.9%. Higher prevalence of obesity-associated diseases, including hypertension (21.3%) and type 2 diabetes (10.5%) were observed in the “under-estimation” group.

Subjects who underestimated their weight-status had more obesity-associated diseases. Accurate self-perception of weight-status carries clinical and behavioral significances. Enhancing the accuracy of self-perceived weight-status through public education should be warranted.