Objective: To develop waist circumference percentile curves for British children and to compare these curves with those from other countries. Design: Cross-sectional study. Setting: School-aged population. Subjects: A representative sample of school children from the geographical regions of Great Britain, approximately in proportion to their age distribution. The sample population consisted of 8355 children (3585 males, 4770 females) with ages ranging between 5.0 and 16.9 y. Interventions: Waist circumferences were measured with a flexible non-elastic tape and waist circumference percentiles were constructed and smoothed using the LMS method. Main outcome measures: Smoothed waist circumference percentile curves. Results: Mean waist circumference increased with age in both boys and girls. For girls, curves began to plateau after the age of 13 y whereas, for boys, waist percentile curves continued to increase more sharply after this age. However, these curves mainly reflect the patterns of waist circumference in Caucasian children. Conclusions: These curves represent the first waist circumference percentiles for British children and could be used provisionally for both clinical and possibly epidemiological use, although they should be validated against equivalent longitudinal data. Sponsorship: This project has been sponsored by UNL Diversity and Development Fund.

OBJECTIVE:To compare waist circumference (a measure of central fatness) and body mass index (BMI, a measure of general fatness) between a contemporary cohort and similar aged British children measured in 1987. DESIGN: Comparative study of two cohorts. The first was a cross-sectional survey and the second an ongoing longitudinal survey. SETTING: The cross-sectional study was conducted throughout Great Britain during 1987. The ongoing longitudinal study was conducted in the Avon region between 1995 and 1998. PARTICIPANTS: A total of 1821 children were measured in the cross-sectional study, and around 1000 children were measured in the longitudinal study. Ages ranged between 2 and 5 y. MAIN OUTCOME MEASURES: Waist circumference, height, weight and BMI. Values were expressed as mean7s.d. Age-related measures were compared. RESULTS: At equivalent ages, mean waist circumference values were greater in the contemporary children, compared with children measured in the earlier cross-sectional study in 1987 (Po0.05). Although boys from the contemporary cohort had the larger absolute waist circumference measurements, the absolute and percentage differences in waist circumference between the cohorts were greater for the girls. Mean BMI values were slightly but significantly higher in the contemporary children compared with children measured in the earlier cross-sectional study (Po0.05). The proportional increase in waist circumference for each age-sex group generally exceeded the proportional increase in BMI. CONCLUSION: These results suggest that central fatness in young British children has increased over the period of 1987-97 to a greater extent than general fatness. This should be of concern since evidence associates greater central adiposity with adverse levels of cardiovascular risk factors in children. Furthermore, the study highlights important shortcomings of the BMI measurement, in that it provides no information on body fat distribution and can mask true obesity-related risk in children.