BMI Perception: A potential cheap alternative to objectively measured BMI?

Background Accurately measuring BMI in large epidemiological studies is problematic as objective measurements are expensive, so subjective methodologies must usually suffice. A number of subjective methodologies have been shown to be inaccurate, resulting in misclassification to a lower BMI category and a subsequent underestimation of obesity prevalence. The purpose of this study is to explore a new subjective method of measuring BMI, BMI perception. Methods A cross-sectional analysis of the Mitchelstown Cohort Rescreen study, a random sample of 1 354 men and women aged 51–77 years recruited from a single primary care centre. Data were collected using self-administered questionnaires. BMI perception was measured by asking “Do you think you are underweight, normal weight, overweight or obese?” Weight and height were also objectively measured. Results 79% of the cohort were overweight or obese: 86% of males, 69% of females, P