Assessing the impact of adjusting for maturity in weight status classification in a cross-sectional sample of UK children

Abstract

ObjectivesTo compare the weight categorisation of a cohort of UK children using standard procedures (ie, comparing body mass index (BMI) centiles to age-matched UK reference data) versus an approach adjusted for maturation status (ie, matching relative to biological age).DesignAnalysis of data collected from an observational study of UK primary school children.SettingSchools in South West England.ParticipantsFour hundred and seven 9–11 year-old children (98% white British).Main outcome measuresWeight status was classified using BMI centiles using (1) sex and chronological age-matched referents and (2) sex and biological age-matched referents (based on % of predicted adult stature) relative to UK 1990 reference growth charts. For both approaches, children were classified as a normal weight if >2nd centile and <85thcentile, overweight if 85th and <95thcentiles, and obese if ≥95thcentile.ResultsFifty-one children (12.5%) were overweight, and a further 51 obese (12.5%) according to standard chronological age-matched classifications. Adjustment for maturity resulted in 32% of overweight girls, and 15% of overweight boys being reclassified as a normal weight, and 11% and 8% of obese girls and boys, respectively, being reclassified as overweight. Early maturing children were 4.9 times more likely to be reclassified from overweight to normal weight than ‘on-time’ maturers (OR 95% CI 1.3 to 19).ConclusionsIncorporating assessments of maturational status into weight classification resulted in significant changes to the classification of early-maturing adolescents. Further research exploring the implications for objective health risk and well-being is needed.

Recreational football is medicine against non‐communicable diseases: A systematic review

“…These contradictory results are in line with the general physical activity literature that suggests that moderate‐to‐vigorous physical activity is not necessarily associated with lower body mass index or fat mass and is part of a multifaceted relationship . Nevertheless, we should be aware that the use of body mass index for establishing weight status in relation to health risk in children is problematic, particularly during the period of peak growth velocity . Results from previous studies that evaluated effects of the school‐based intervention “FIFA 11 for Health” warn for the necessary caution in the interpretation of these type of results.…”

“…[52][53][54] Nevertheless, we should be aware that the use of body mass index for establishing weight status in relation to health risk in children is problematic, particularly during the period of peak growth velocity. 55 Results from previous studies 56 that evaluated effects of the school-based intervention "FIFA 11 for Health" warn for the necessary caution in the interpretation of these type of results.…”

The Main and Interactive Effects of Biological Maturity and Relative Age on Physical Performance in Elite Youth Soccer Players

“…Estimated biological maturity status was expressed as a "z-score" relative to age and sex specific means and standard deviations for percentage of mature height attained at half-yearly intervals [35]. e z-scores were also used to classify each participant as either early, on time, or late in maturity, as used in previous studies [36][37][38]. Individuals that achieved a z-score of between −1 and +1 were classified as on time in maturity status, if individuals achieved a z-score greater than +1, they were defined as early in maturity status, and if individuals achieved a zscore less than −1, they were defined as late in maturity status.…”

Developmental fitness curves: assessing sprint acceleration relative to age and maturity status in elite junior tennis players

“…Current height was then expressed as a percentage of predicted adult height attained at the time of observation, which is an indicator of maturity status (Roche et al 1983). Percentage of predicted adult height attained at time of observation for each player was then compared to age-and sex-specific growth reference data for the UK (Freeman et al 1995;Gillison et al 2017) to derive an index of maturity status, labelled biological age (BA), for each participant. Sex-specific reference values for percentage of adult stature were calculated at approximately 0.1 yearly intervals relative to the UK reference data.…”