Self-reported versus measured height, weight and body mass index amongst 16 - 17 year old British teenagers

OBJECTIVE: To examine the relationships between reported and measured height and weight in a teenage population group, and to assess the impact this may have on estimates of overweight. DESIGN: Data were taken from a sample of teenagers from the 1970 Birth Cohort Study. Multivariate normal regression was used to model differences between self-reported and measured height and weight, using both BMI and a number of other personal and demographic variables to examine influences on reporting differences. RESULTS: Tall, thin individuals were more likely to under-report their height and shorter, fatter individuals to overestimate their height and under-estimate their weight. Self-reported height and weight data when used to calculate BMI would result in a lower estimate of overweight teenagers. Self-assessment of body fatness, (but no other personal or demographic variable), was influential on the height and weight reporting of females in this study. CONCLUSION: Self-reported height and weight data from a teenage population should be used with caution, particularly if classifying individuals by BMI or when using weight measurements to estimate energy requirements.