Reassessing Ethnic Differences in Mean BMI and Changes Between 2007 and 2013 in English Children.

Mohammed T Hudda,Angela S Donin,Claire M Nightingale,Alicja R Rudnicka,Jonathan C K Wells,Peter H Whincup,Harry Rutter,Christopher G Owen,Derek G Cook

doi:10.1002/oby.22091

Abstract

ObjectiveNational body fatness (BF) data for English South Asian and Black children use BMI, which provides inaccurate ethnic comparisons. BF levels and time trends in the English National Child Measurement Programme (NCMP) between 2007 and 2013 were assessed by using ethnic‐specific adjusted BMI (aBMI) for South Asian and Black children.MethodsAnalyses were based on 3,195,323 children aged 4 to 5 years and 2,962,673 children aged 10 to 11 years. aBMI values for South Asian and Black children (relating to BF as in White children) were derived independently. Mean aBMI levels and 5‐year aBMI changes were obtained by using linear regression.ResultsIn the 2007‐2008 NCMP, mean aBMIs in 10‐ to 11‐year‐old children (boys, girls) were higher in South Asian children (20.1, 19.9 kg/m2) and Black girls, but not in Black boys (18.4, 19.2 kg/m2) when compared with White children (18.6, 19.0 kg/m2; all P < 0.001). Mean 5‐year changes (boys, girls) were higher in South Asian children (0.16, 0.32 kg/m2 per 5 y; both P < 0.001) and Black boys but not girls (0.13, 0.15 kg/m2 per 5 y; P = 0.01, P = 0.41) compared with White children (0.02, 0.11 kg/m2 per 5 y). Ethnic differences at 4 to 5 years were similar. Unadjusted BMI showed similar 5‐year changes but different mean BMI patterns.ConclusionsBF levels were higher in South Asian children than in other groups in 2007 and diverged from those in White children until 2013, a pattern not apparent from unadjusted BMI data.

Highlights

High levels of body fatness (BF), overweight, and obesity in children represent a major global public health challenge [1]
High BF in South Asian and Black children in England is of particular concern because both ethnic groups have high risks of type 2 diabetes (T2D) and cardiovascular disease (CVD) in adulthood [7,8,9,10] compared with White children; these risks have their origins in childhood [11,12]
The proportion of participants with unknown ethnic origin declined with improvements in the completeness of ethnic group recording between 2007-2008 and 2012-2013; the proportions of children of White, Black African, and Pakistani origin showed increases over the same period

Summary

Introduction

High levels of body fatness (BF), overweight, and obesity in children represent a major global public health challenge [1]. High BF in South Asian and Black children in England is of particular concern because both ethnic groups have high risks of T2D and CVD in adulthood [7,8,9,10] compared with White children; these risks have their origins in childhood [11,12]. Notably the National Child Measurement Programme (NCMP), have used BMI to categorize overweight and obesity, using identical BMI thresholds in all ethnic groups that are based on an exclusively White reference population [13,14]. The associations between childhood BMI and BF differ by ethnic group; BMI systematically underestimates BF in South Asian children and overestimates BF in Black children [15,16].

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Discussion

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