Official Statistics

Obesity Profile: statistical commentary November 2023

Published 7 November 2023

Applies to England

Introduction

The November 2023 update of the Obesity Profile presents the 2022 to 2023 academic year National Child Measurement Programme (NCMP) data for all current indicators.  Headline findings from these data have already been published by NHS England on the 19 October 2023 in their NCMP 2022 to 2023 school year report.

The prevalence of obesity among reception children in the academic year 2022 to 2023 shows a 1.0 (values may not sum due to rounding) percentage point (pp) decrease in obesity prevalence to 9.2%. The decrease is a return to pre-pandemic levels for this age group and is one of the lowest levels since the academic year 2006 to 2007.

Data from the academic year 2022 to 2023 for children in year 6 has shown a 0.8 pp (values may not sum due to rounding) decrease to 22.7% which is still above pre-pandemic levels and reflects the long term trend of increasing obesity prevalence which was evident before the pandemic.

This update of the obesity profile provides data at national level, regional, upper and lower tier local authority, integrated care board (ICB), Middle Super Output Area (MSOA) and electoral ward.

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 primary schools across England. The data is used at a national and local level to monitor the patterns and trends in child weight status providing valuable evidence for planning and delivering policy measures and interventions.

What’s new

The following indicators have been updated with 2022 to 2023 NCMP data for national, regional, upper and lower tier local authority and integrated care boards (ICBs) geographies:

Indicators using one year of data

• reception and year 6: prevalence of underweight

• reception and year 6: prevalence of healthy weight

• reception and year 6: prevalence of overweight (including obesity)

• reception and year 6: prevalence of overweight

• reception and year 6: prevalence of obesity (including severe obesity)

• reception and year 6: prevalence of severe obesity

• reception and year 6: prevalence of obesity (including severe obesity), 5 years of data combined

Indicators using 3 or 5 years of data combined

Local authority level inequalities data is presented using the reception and year 6: Prevalence of obesity (including severe obesity), 5 years of data combined indicators. Prevalence of obesity by sex, ethnic group and deprivation quintile can be examined for upper and lower tier local authorities in the Inequalities data view of the Obesity Profile.

The following indicators have been updated in the NCMP small area data topic showing data for MSOAs and electoral wards, together with local authority and England figures for comparison.

• reception: prevalence of obesity (including severe obesity), 3 years data combined

• reception: prevalence of overweight (including obesity), 3 years data combined

• year 6: prevalence of obesity (including severe obesity), 3 years data combined

• year 6: prevalence of overweight (including obesity), 3 years data combined

The small area data is presented by area of child residence using 3-year combined NCMP data to show small area trends from 2008 to 2009 up to 2022 to 2023. This data will assist planning and delivery of services for children and the targeting of resources at a local level to help reduce the prevalence of overweight and obesity.

Slide packs showing data on the patterns and trends in child obesity

The national and regional patterns and trends in child obesity data slide packs have also been updated with 2022 to 2023 NCMP data and is available in the reports data view.

Main findings

This statistical commentary focuses on the overall trend in child obesity prevalence in England. Projections of obesity prevalence for reception and year 6 have been produced based on pre-COVID-19 data from 2006 to 2007 through to 2019 to 2020.  This allows a comparison between the latest estimates of obesity prevalence with the pre-pandemic trend projected forward.

The projection is presented with 95% confidence intervals, this is a range of values that is used to quantify the uncertainty in the projection.  The observed prevalence estimates also have a small level of uncertainty even though nearly all children are measured each year. This primarily reflects the natural variation which would occur if the measurements were taken on a different day.

The data used to produce the charts can be downloaded as an accessible spreadsheet, this spreadsheet also contains the methods used to produce the projections.

For reception children:

• in 2020 to 2021 the observed prevalence of obesity (14.4%) was well above the projection based on the pre-pandemic trend

• in 2021 to 2022 the observed prevalence of obesity (10.1%) was within the confidence interval for the projection

• in 2022 to 2023 the observed obesity prevalence (9.2%) had decreased to one of the lowest levels seen in the NCMP data collection.  The confidence interval for this estimate just overlaps the confidence interval for the projection showing that this new obesity prevalence estimate for 2022 to 2023 is similar to the trend seen in the pre-pandemic data

Figure 1: Observed prevalence of obesity among reception children (age 4 to 5 years) for academic years ending 2008 to 2023, compared to projected prevalence for 2020 to 2021 through to 2022 to 2023. Forecasts, with 95% confidence intervals, are based on data from 2006 to 2007 through to 2019 to 2020.

For year 6 children:

• in 2020 to 2021 the observed prevalence of obesity (25.5%) was well above the projection based on the pre-pandemic trend

• although the observed obesity prevalence has seen decreases each year in academic years ending 2022 and 2023 (23.4% and 22.7% respectively) prevalence remains above the projection based on the pre-pandemic trend

Figure 2: Observed prevalence of obesity among year 6 children (age 10 to 11 years) for academic years ending 2008 to 2023, compared to projected prevalence for 2020 to 2021 through to 2022 to 2023. Forecasts, with 95% confidence intervals, are based on data from 2009 to 2010 through to 2019 to 2020.

For year 6, comparisons are not possible with the first years of the NCMP (2006 to 2007 to 2008 to 2009) as low participation levels led to underestimation of obesity prevalence.

Data quality

Details of the impact of the COVID-19 pandemic on the data can be found in the “Impact of COVID-19” section of Definitions in the Obesity Profile.

Background

Further information about this publication and the data used

For population monitoring purposes, a child’s body mass index (BMI) is classed as overweight or obese where it is on or above the 85th centile or 95th centile, respectively, based on the British 1990 (UK90) growth reference data. The population monitoring cut offs for overweight and obesity are lower than the clinical cut offs (91st and 98th centiles for overweight and obesity) used to assess individual children; this is to capture children in the population in the clinical overweight or obesity BMI categories and those who are at high risk of moving into the clinical overweight or clinical obesity categories. This helps ensure that adequate services are planned and delivered for the whole population.

Previous Obesity Profile statistical commentaries have given guidance on the interpretation of small area data. Detailed metadata for each indicator is available in the definitions tab of the Obesity profile.

Further information on the NCMP data set and data collection is available in the guidance for analysis and data sharing and operational guidance.

The statistics were produced using the national analysis dataset provided to OHID by NHS England.

In the NCMP since 2008 to 2009, over 99% of child records have a valid postcode, providing large enough coverage to produce reliable estimates at small area level.

Responsible statistician, product leads: Caroline Hancock, Catherine Bray

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