Validity of Self-reported Height, Weight, Body Mass Index, and Waist Circumference in Iranian Adults

The validity of self-reported anthropometric indices has been examined in previous studies in different populations.

The aim of our study was to evaluate the validity of self-reported height, weight, body mass index (BMI), and waist circumference (WC) for the first time in middle-age staffs of Isfahan University of Medical Sciences.

In this cross-sectional study, a total of 171 men and women were selected from staffs of Isfahan University of Medical Sciences, Isfahan, Iran.

Technician- and self-reported measurements of height, weight, and WC were collected from all participants. BMI was calculated by dividing weight in kg by height in meters squared. Overweight and obesity were defined as BMI ≥25-<29.9 and ≥30 kg/m², respectively. Abdominal obesity was defined as WC ≥94 and ≥80 cm in men and women, respectively.

Independent t-test, chi-square, Pearson and intraclass correlation coefficients (ICCs), as well as Kappa measurements, were used.

Fifty and 19 percentages of the study population were overweight and obese, respectively. Self-reported height (r = 0.83, P < 0.001, ICC =0.89, 95% confidence interval (CI): 0.85-0.92), weight (r = 0.95, P < 0.001, ICC = 0.979, 95% CI: 0.971-0.98), BMI (r = 0.70, P < 0.001, ICC = 0.81, 95% CI: 0.74-0.86), and WC (r = 0.60, P < 0.001, ICC = 0.71, 95% CI: 0.51-0.81) were highly correlated with actually measured ones. Approximately 80% and 65% of individuals who were defined as overweight and obese, respectively, based on actually measured data were correctly diagnosed as overweight and obese, respectively, based on self-reported data. The Kappa coefficients for different categories of weight situation and abdominal obesity were 0.59 and 0.32, respectively. Fifty-seven percent of participants who were diagnosed with abdominal obesity based on actually measured data were correctly diagnosed with abdominal obesity based on self-reported data. Also, approximately 48% and 69% of men and women, respectively, who were diagnosed with abdominal obesity based on actually measured data were correctly diagnosed with abdominal obesity based on self-reported ones.

We found that self-reported data of anthropometric measures are reasonable in middle-age staff of Isfahan University of Medical Sciences. Nevertheless, self-reported data on WC should be cautiously relined on, in particular, among men.