‘British children are not shrinking’, but child height is increasing for the wrong reasons: trends and inequalities in child measurement programme data for England, Scotland and Wales

BACKGROUND: News media have reported that the average height of British children is falling, but these reports have been contested. Child Measurement Programmes (CMPs) operate in schools in England, Scotland and Wales, but their height data have been inaccessible, allowing conflicting claims about trends in child height to remain unresolved. Here, we aim to describe and explain trends and socioeconomic inequalities in child height using the best available evidence. METHODS: Freedom of information requests were submitted to relevant authorities in England, Scotland and Wales, requesting annual CMP height and obesity data, stratified by sex, ethnicity and deprivation to 2023/2024. Mean height and obesity prevalence were plotted against time by age group, sex and deprivation group. RESULTS: The COVID-19 pandemic prompted school closures in Britain, disrupting CMP data collection. This period was associated with sharp but transient increases in obesity prevalence and mean height. Before COVID-19, mean height increased, particularly among children in deprived areas. Children in deprived areas also showed the greatest increases in obesity and overweight prevalence. Narrowing socioeconomic inequalities in child height in Britain have been associated with widening inequalities in obesity. CONCLUSIONS: This work complements research describing a causal link from child obesity to increased height during childhood and implies mean height may be an unreliable indicator of child health when obesity is prevalent and rising. In Britain, increases in overall mean child height and narrowing socioeconomic inequalities in child height during the 21st century may reflect widening inequalities in obesity and worsening health among deprived children.