Objectives To develop waist circumference (WC) centile curves for UK South Asian children, to make comparisons with published centiles for British, indigenous Indian and Pakistani children, as well as to make anthropometric comparisons with their UK white peers.

Design Cross-sectional study.

Setting School-aged children from London boroughs (main measures: 2004–2007).

Participants 1562 (652 boys, 910 girls) UK South Asian and 1120 (588 boys, 532 girls) UK white children aged 4.0–13.9 years.

Interventions WC, height, weight and body mass index (BMI).

Main outcome measures The outcome measures were smoothed WC centile curves, constructed using the LMS (L = skewness, M = median, S = coefficient of variation) method. SD scores (SDS) were generated using UK90 and British (WC) growth references.

Results WC increased with age for both sexes, rising more steeply at the upper centiles after the age of 6 years. Overall, UK South Asian children, similar to indigenous South Asian populations, had higher WC values than the British WC references. However, compared with their UK white peers, UK South Asian children had significantly (p<0.001) lower mean WC (UK white SDS=0.74 and SDS=0.64 vs UK South Asian SDS=0.32 and SDS=0.21 for boys and girls, respectively). Obesity prevalence was greater using WC than BMI for both ethnicities. At the 90th centile, for UK South Asian children, prevalence was 21.5% vs 24.4% for boys and 17% vs 24.5% for girls based on BMI and WC, respectively.

Conclusions These curves represent the first WC centiles for UK South Asian children up to the age of 14 years. With a continued rise in childhood obesity, they provide a useful historical control for future comparisons.