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Publication, Part of

National Child Measurement Programme, England 2018/19 School Year [NS]

Official statistics, National statistics

National Statistics
Page contents


Child obesity is a good indicator of adult obesity which can lead to poor health outcomes. 

The NCMP is a key element of the Government’s approach to tackling child obesity by annually measuring over one million children and providing reliable data on rates of childhood obesity. Children are measured in reception (aged 4–5 years) and year 6 (aged 10–11 years) in mainstream state-maintained schools in England. Independent and special schools are excluded.  See “Coverage” in annex B of the appendices for more details.

The programme was launched in the 2005/06 academic year and now holds thirteen years of reliable data. 2006/07 is the first year that the data are considered to be robust due to the low participation in 2005/06.

NCMP data enables local areas to plan services to tackle child obesity and monitor progress.

In most local authorities, parents also receive feedback on their child’s weight status along with the offer of further advice and support on achieving a healthy weight for their child.

This report contains analyses of the 2018/19 data showing Body Mass Index (BMI) classification rates with breakdowns by: child age and sex; local authority and region; levels of deprivation; urban/rural classification; ethnicity and ONS area classification. The report also contains comparisons over time where appropriate.

Comparisons between groups and over time have been statistically tested to determine whether differences are likely to be genuine (i.e. statistically significant) or the result of random natural variation. Only statistically significant differences have been described with terms such as “higher”, “lower”, “increase” or “decrease”. When a comparison does not show a statistically significant difference, this will be described using terms such as “similar to” or “the same as". 

The report is accompanied by:

  • Data tables, including 95 per cent confidence intervals which should be considered when interpreting results.
  • Technical appendices with information on data collection, validation, confidence intervals, statistical testing and the methodology used for BMI classification rates.
Definitions used in the publication

The BMI classification of each child is derived by calculating the child’s BMI centile and classifying as follows:

  • BMI centile <=2: Underweight
  • BMI centile >2 and <85: Healthy weight
  • BMI centile >=85 and <95: Overweight
  • BMI centile >=95: Obese
  • BMI centile >=99.6 Severely obese. Note:  “Severely obese” is a subset of “Obese”. Children with a BMI centile of between 95 and 100 are classified as “Obese” and those with a BMI centile of between 99.6 and 100 are classified as “Severely obese”

This calculation uses age and sex as well as height and weight to take into account different growth patterns in boys and girls at different ages. A child’s BMI centile is a measure of how far a child’s BMI is above or below the average BMI value for their age and sex in a reference population. The NCMP uses the British 1990 growth reference (UK90) to define the BMI classifications.  This approach is recommended by The National Institute for Health and Care Excellence (NICE). See “Calculation of prevalence” in annex B of the appendices for more details.

The prevalence of children in a BMI classification is calculated by dividing the number of children in that BMI classification by the total number of children and multiplying the result by 100.

Geographical analyses in this report are primarily based on the postcode of the child’s home address which is mapped to a lower super output area.  Some time series analyses use the school postcode as the child postcode was poorly populated in the early years of the NCMP and these are labelled in the report.

Last edited: 23 June 2021 5:21 pm