Commentary on data from the National Child Measurement Programme (NCMP) for the academic years 2008 to 2009 through to 2023 to 2024, describing patterns in child height.

What’s new

The February 2025 update of the obesity profile presents new data on mean height and prevalence of short stature for children measured in the NCMP.

Introduction

The NCMP is an annual programme that measures the height and weight of over one million children in reception (age 4 to 5 years) and year 6 (age 10 to 11 years) in state-funded primary schools across England.

Child height and growth patterns can be reflective of conditions in society; it is important to monitor child height and prevalence of short stature at a population level as an improvement or worsening of the social and economic environment can impact growth patterns in children^{[footnote 1]}.

Around 80% of the variance in height can be attributed to genetic factors, leaving 20% explained by environmental influence, with infancy being a particularly sensitive phase regarding external influences^{[footnote 2] [footnote 3]}. There are many modifiable environmental factors that influence a child’s height and growth that start in utero and continue through postnatal growth through to puberty and up to adulthood. These include maternal smoking in pregnancy, parental and other passive smoking, diet and nutrition, living conditions, childhood diseases and psychological stress ^{[footnote 4] [footnote 5]}.

The Royal College of Paediatrics and Child Health states that poor growth in infancy is associated with high childhood morbidity and mortality, with child growth acting as an important indicator of health and wellbeing.

The World Health Organization (WHO) monitors child growth in terms of stunting and wasting as part of the United Nations (UN) Sustainable Development Goal to end all forms of malnutrition.

Main findings

Trend in the mean height of children aged 5 and 11 years in England

The average height of 5 year old boys and girls in England increased slightly over the period of NCMP data collection up to 2019 to 2020. This was followed by a relatively large increase in average height in 2020 to 2021 which coincided with the large increase in the prevalence of obesity during the COVID-19 pandemic. Since 2020 to 2021 average height of 5 year olds has decreased and is now similar to 2018 to 2019 (figure 1).

Boys were on average taller than girls at age 5; the data for 2023 to 2024 shows that mean height in 5 year old boys was 110.3cm and in girls it was 109.3cm.

Figure 1: trend in average (mean) height in centimetres at age 5 in England for academic years ending 2009 to 2024

Data source: National Child Measurement Programme. Note: y axis does not start at zero.

The average height of 11 year olds in England increased slightly over the period of NCMP data collection up to 2019 to 2020. As with 5 year olds, there was a relatively large increase in average height in 2020 to 2021 which coincided with a large increase in the prevalence of obesity during the pandemic. Since 2021 to 2022 average height of girls has decreased but remains above pre-pandemic levels. Average height of boys has remained above pre-pandemic levels and has not decreased since the pandemic (figure 2).

Girls were on average taller than boys at age 11; the data for 2023 to 2024 shows that mean height in 11 year old girls was 147.5cm and in boys it was 146.4cm.

Figure 2: trend in average (mean) height in centimetres at age 11 in England for academic years ending 2009 to 2024

Data source: National Child Measurement Programme. Note: y axis does not start at zero.

As children are growing all the time it is important to ensure any changes in average height are not due to children being measured earlier or later in the academic year. Therefore, the height estimates have been standardised to be the height of a child aged exactly 5 years and 0 days for reception year and exactly 11 years and 0 days for year 6. More information on how this is calculated is available in the Definitions data view in the obesity profile.

Mean height by body mass index (BMI) category

Evidence from research literature shows that children living with obesity are, on average, taller than their healthy weight peers as obesity is associated with an accelerated height gain in childhood, but this is followed by a ‘catch-down’ of reduced height gain in adolescence, and earlier onset of puberty^{[footnote 6] [footnote 7] [footnote 8] [footnote 9] [footnote 10]}.

Mean height among 5 year olds increased across BMI categories in 2023 to 2024, for both boys and girls, from underweight (108.7cm boys, 107.6cm girls) through to those living with obesity (113.2cm boys, 112.5cm girls), (figure 3).

Figure 3: average (mean) height in centimetres at age 5 by BMI category in England for academic year 2023 to 2024

Data source: National Child Measurement Programme. Note: y axis does not start at zero.

Mean height among 11 year old boys and girls also increased across BMI categories from underweight (141.8cm boys, 141.9cm girls) through to those living with obesity (149.9cm boys, 151.1cm girls), (figure 4).

Figure 4: average (mean) height in centimetres at age 11 by BMI category in England for academic year 2023 to 2024

Data source: National Child Measurement Programme. Note: y axis does not start at zero.

This pattern is consistent across all years of NCMP data collection. Trend data is shown in the inequalities data view within the obesity profile.

Geographic variation in mean height

Mean height of 5 year olds varies across upper tier local authorities in England, for boys from 109.4cm in Herefordshire to 111.4cm in Greenwich, and for girls from 108.3cm in Blackburn with Darwen to 110.7cm in Greenwich in 2023 to 2024. Among children aged 11 years mean height in 2023 to 2024 varied from 145.2cm for boys and 146.1cm for girls in Blackburn with Darwen to 147.7cm for boys and 149.8cm for girls in Southwark. Differences in mean height between local authorities may be, in part, due to differences in demographics or prevalence of obesity in the local population.

Trend in the prevalence of short stature

Short stature is defined as height below the 2nd centile of the British 1990 (UK90) growth reference. However, in a clinical setting, other factors would be considered in the assessment of height in individual children, such as comparing the child’s height to the height that would be expected based on the height of their parents - this is known as the mid-parental height (MPH)^{[footnote 11]}.

Prevalence of short stature among children in reception (age 4 to 5 years) is low (figure 5) and was 1.8% in 2018 to 2019. It decreased during the COVID-19 pandemic but returned to 1.8% in 2023 to 2024.

Prevalence of short stature among children in year 6 is lower than in reception children; in 2018 to 2019 1.1% of children had short stature, this decreased to 0.7% in 2020 to 2021 and has remained less than 1% since the pandemic and is now 0.9% in 2023 to 2024, (figure 5).

Figure 5: prevalence of short stature in England by school year for academic years ending 2010 to 2024

Data source: National Child Measurement Programme.

Prevalence of short stature by deprivation

There are inequalities in the prevalence of short stature among children in England. In 2023 to 2024, children in reception living in the most deprived areas had a higher prevalence of short stature (2.3%) than those living in the least deprived areas (1.4%), (figure 6).

Figure 6: prevalence of short stature in England by deprivation decile among reception children (age 4 to 5 years) for academic year 2023 to 2024 with 95% confidence intervals.

Data source: National Child Measurement Programme.

In 2023 to 2024, 1.1% of year 6 children living in the most deprived areas had short stature compared to 0.6% of children in the least deprived areas, (figure 7).

Figure 7: prevalence of short stature in England by deprivation decile among year 6 children (age 10 to 11 years) for academic year 2023 to 2024 with 95% confidence intervals

Data source: National Child Measurement Programme.

Data for prevalence of short stature by sex and ethnicity is shown for England in the obesity profile.

Geographic variation in the prevalence of short stature

The prevalence of short stature varies between upper tier local authorities in England; among reception children in 2023 to 2024 prevalence was highest in Leicester (3.2%) and lowest in Richmond upon Thames (0.9%). For year 6 children prevalence of short stature in 2023 to 2024 was highest in Knowsley (1.6%) and lowest in Lambeth (0.4%).

Further information

Further work to adjust trends in mean child height for the various factors that may influence child growth is required to understand these patterns and trends in more detail.

List of new indicators

The following new indicators on child height have been added to the obesity profile:

• mean height (cm) of boys aged 5 years

• mean height (cm) of girls aged 5 years

• mean height (cm) of boys aged 11 years

• mean height (cm) of girls aged 11 years

• reception prevalence of short stature (height less than 2nd centile)

• year 6 prevalence of short stature (height less than 2nd centile)

Data is presented for England, statistical regions, local authorities and integrated care boards (ICBs), with inequalities data for England by sex, ethnic group and deprivation decile. Detailed metadata describing each indicator is available in the Definitions data view of the obesity profile.

The statistics were produced using the national NCMP analysis dataset provided to the Office for Health Inequalities and Disparities by NHS England.

Index of Multiple Deprivation (IMD) decile used in the analysis is assigned to each child measurement record in the NCMP based on the lower super output area (LSOA) of the postcode of child residence.

Update to slide set showing data on the patterns and trends in child obesity

The national child obesity slide set has been updated to include England level data for the new height indicators.

Adult obesity prevalence from the Health Survey for England

Data has been added to the obesity profile showing prevalence of obesity in adults (aged 16 and over) for England and regions from the Health Survey for England. This data has been previously published by NHS England.

References

Responsible statistician, product leads: Caroline Hancock, Catherine Bray

For queries relating to this document, please contact: PHA-OHID@dhsc.gov.uk.