Launched in 2005/06, the National Child Measurement Programme (NCMP) measures over one million children each year and is a valuable source of data on childhood obesity.
The data only includes children in state-maintained schools that participated in the programme. In 2017/18 there were 1,187,009 participants, with 5% of pupils opting out.
Measurements of height and weight are collected from children in reception (ages 4 to 5) and year 6 (ages 10 to 11), primarily in state-maintained schools in England. This data is then used to calculate the percentage of overweight children. Be aware that although the figures provided are reliable estimates, it is impossible to be 100% certain of the true percentage.
Confidence intervals: Confidence intervals for each ethnic group are available if you download the data.
Based on the NCMP measurements, it is estimated that 22.4% of children aged 4 to 5 and 34.3% of children aged 10 to 11 were overweight in England in 2017/18.
It is 95% certain, however, that somewhere between 22.3% and 22.5% of all 4 to 5 year olds and 34.2% and 34.4% of all 10 to 11 year olds were overweight in 2017/18. In statistical terms, this is a 95% confidence interval. This means that if 100 random samples were taken from the total population of school age children in England, then 95 times out of 100 the estimate would fall between the upper and lower confidence interval. But 5 times out of 100 it would fall outside this range.
The smaller the size of the population, the less certain the estimate and the wider the confidence interval. For example, there are fewer Chinese children in state schools in England than White British children, so we can be less certain about the estimate for this group. A wider confidence interval expresses this greater uncertainty. So, in 2017/18 between 17.0% and 19.6% of Chinese children aged 4 to 5 were overweight. Statistically significant findings have been determined when compared to the England average where the 95% confidence intervals of an ethnic group do not overlap with the England value.
Suppression rules and disclosure control
England totals include all children in state-maintained schools, with a valid height and weight measurement, including those with an unknown residency.
Figures have been rounded to one decimal point.Quality and methodology information