Changes in waist circumference among adolescents in England from 1977-1987 to 2005-2007

To assess change in abdominal obesity in adolescents in England.

Health Survey for England (HSE), annual cross-sectional surveys of nationally representative samples in England.

This study included 1770 children aged 11-16 years in HSE 2005-2007 with valid waist circumference (WC) measurements. WC and body mass index (BMI) were expressed as standard deviation scores (z scores) against the growth references used for British children.

Mean WC z scores were substantially higher than mean BMI z scores for both sexes: WC 1.0 [95% confidence interval (CI) 0.93-1.1], BMI 0.54 (95% CI 0.44-0.63) for boys; WC 1.3 (95% CI 1.2-1.4), BMI 0.48 (95% CI 0.40-0.56) for girls (both P < 0.001). Mean WC z score was higher for girls than boys (P < 0.001). Between 1997 and 2005-2007, WC increased for both boys (P < 0.01) and girls (P < 0.001), but BMI did not (P > 0.05). Only children in the lowest WC decile had an increase in WC z score less than +1 standard deviation compared with the 1977-1987 baseline. BMI z score increased across the top nine deciles of the BMI distribution by 0.4 (2nd-4th deciles) to 0.9 (top decile).

WC in adolescents has increased substantially, and probably more than BMI. The whole population has become fatter.