Cross‐Sectional Comparisons of BMI and Waist Circumference in British Children: Mixed Public Health Messages

Abstract

Research suggests that there has been a leveling off in obesity prevalence occurring in the child population. However, a concern with the evidence base is that all of the studies have relied upon the use of BMI. The purpose of this study was to compare waist circumference (WC), BMI, and waist‐to‐height ratio (WHtR) data in three different sample of children (total number: 14,697) typically aged 11–12 years. Obesity prevalence defined by BMI did not change significantly between measurement years (2005 boys 20.6%, girls 18.0%; 2006 boys 19.3%, girls 17.3%; 2007 boys 19.8%, girls 16.4%). Obesity prevalence defined by WC was considerably higher especially, in girls (2005 boys 26.3%, girls 35.6%; 2006 boys 20.3%, girls 28.2%; 2007 boys 22.1%, girls 30.1%). The prevalence of children defined as “at risk” according to WHtR (2005 boys 23.3%, girls 21.1%; 2006 boys 16.7%, girls 15.6%; 2007 boys 17.6%, girls 17.2%) was found to be between obesity prevalence, estimated using BMI and WC. This data are the most up to date collection that includes BMI and WC in three large samples of children and clearly demonstrates inconsistencies between different measurements based on current classification systems. There is a need to understand the relationship between BMI and WC, with growth and health risk to establish a consistent public health message that is easily understood by the public.

Area-level deprivation and adiposity in children: is the relationship linear?

“…These results confirm that there are inconsistencies between the different measures of obesity, with the greatest prevalence observed in central obesity, which is in agreement with previous research (30,31). However, the most important message here is that, the relationship between obesity and deprivation seems not to be linear.…”

“…Although the choice of BMI as a measure of obesity in children is well established (27) there is emerging evidence to suggest that central adiposity in children is more relevant to health outcomes than overall adiposity estimated by BMI (28,29). Also the prevalence of central adiposity (measured by waist circumference) is considerably higher than the prevalence of general obesity (measured by BMI) and is increasing at a faster rate (22,30,31). Therefore, the aim of this study is to investigate associations between area level deprivation and three measures of adiposity; BMI, waist circumference (WC) and waist-to-height ratio (WHtR) in children and explore if the relationship is linear.…”

“…These figures demonstrate appropriate reliability (33). All testing took place on school premises; more detailed protocols are reported elsewhere (31).…”

Evidence Update on the Treatment of Overweight and Obesity in Children and Adolescents

“…An ideal measure of weight change should be easily interpreted in clinical practice, be sensitive to change in treatment, take into account age and gender (i.e., be a measure of relative weight), and be reliable and sensitive across a range of values, including the severely obese (Paluch, . The majority of studies reviewed here include one or more of the following as the primary weight loss outcome variable: Standardized Body Mass Index (BMI) scores (BMI z-score or BMI-SDS), percent overweight=percent overBMI (%OW=%overBMI), BMI percentile scores (measures of relative weight; , BMI, absolute weight, waist circumference (Griffiths, Gately, Marchant, & Cooke, 2012), and direct measures of adiposity (body composition, percentage body fat; Basterfield et al, 2012). Of importance, although these measures differ in methodology, they are highly correlated (Cole, Faith, Pietrobelli, & Heo, 2005).…”

“…Directly measures central adiposity, which may be associated with greater health risk in children . Concerns about technical errors in measurement (Griffiths et al, 2012) Body Composition % body fat=body fatness as measured by bioelectrical impedance…”