Obesity

We look at how the proportion of the population who are overweight and obese has changed over time.

Indicator

Last updated: 31/03/2022

Effective clinical care Equity and fairness
Public health Children and young people

Background

Obesity is a major public health problem, both internationally and within the UK. Being overweight or obese is associated with an increased risk of a number of common diseases including diabetes, cardiovascular disease and some cancers. Evidence also suggests that obesity is associated with an increased risk of severe illness and death from Covid-19.  

In July 2020, the government published Tackling obesity: empowering adults and children to live healthier lives, which outlined policies to support healthy eating and expand NHS weight management services. In October 2022, the government will be introducing restrictions to food and drinks high in fat, salt or sugar (HFSS) across medium and large retailers in an attempt to curb the increased prevalence of obesity. 

Childhood obesity is similarly a major public health problem. Children who have obesity are at greater risk of high blood pressure, high cholesterol, diabetes and other long term conditions that last into adulthood. In 2016, the government launched Childhood obesity: a plan for action, which set out a number of actions primarily focused on reducing sugar consumption and increasing physical activity among children. In June 2018, an update to the action plan was published, setting a national ambition to "halve childhood obesity and reduce the gap in obesity between children from the most and least deprived areas by 2030". Obesity is disproportionally prevalent in low-income households and certain ethnicities; these disparities are illustrated in our charts below.


How has the proportion of children aged 10-11 who are overweight and obese changed over time? 31/03/2022

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The National Child Measurement Programme (NCMP) collects the height and weight measurements of over one million children in Reception (aged 4-5 years) and Year 6 (aged 10-11 years) in mainstream state schools in England.

In 2020/21 there was a sizeable increase in the prevalence of obesity in children. One in four children (26%) in Year 6 were obese or severely obese in the 2020/21 school year, up from one in five in 2019/20 (21%). One in seven children (14%) in Reception were obese or severely obese in the 2020/21 school year, up from one in 10 in 2019 (10%). 

Between 2006/07 and 2020/21, the proportion of children with a “healthy weight” decreased by 9 percentage points for those in Year 6 and 4.5 percentage points for those in Reception. The proportion of children who were overweight or underweight has remained relatively stable over this time period.

When looking at the prevalence of obesity by ethnicity for children in Year 6 in 2020/21, children described as “White” (24%) and “Chinese” (24%) had a lower rate of obesity compared to the average (26%). However, children described as being in “mixed”, “Asian” and “Black” ethic groups were above average with rates of obesity of 28%, 31% and 36% respectively. 


How does the prevalence of obesity in children aged 4-5 vary by deprivation? 31/03/2022

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There is a strong association between deprivation and obesity in children. In 2020/21, the prevalence of obesity in children in Reception in the most deprived areas (20%) was more than double the least deprived areas (9.1%). 

Between 2019/20 and 2020/21 prevalence of obesity in Reception aged children increased from 13% to 20% in the most deprived areas; in the least deprived areas this increased from 7% to 9%.  

The government’s Childhood obesity: a plan for action: Chapter 2 has set a national ambition to significantly reduce the gap in obesity between children from the most and least deprived areas by 2030. Between 2006/07 and 2020/21, the gap in obesity prevalence for children aged 4-5 increased from 4.5 to 10.7 percentage points. 


How does the prevalence of obesity in children aged 10-11 vary by deprivation? 31/03/2022

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In 2020/21, there was an increase in the prevalence of obesity in children in Year 6 in both most deprived and least deprived areas of the England – rising to 32% in the most deprived areas and 15% in the least deprived areas. Despite the government setting a national ambition to halve childhood obesity and significantly reduce the gap in obesity between children from the most and least deprived areas by 2030, between 2006/07 to 2020/21 the gap for children aged 10-11 has almost doubled, from 8.5 percentage points to 16.6 percentage points.


How has the proportion of adults who are overweight and obese changed over time? 27/01/2021

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The Health Survey for England collects height and weight measurements from a representative sample of the general population, which are used to calculate body mass index (BMI) statistics. This measure allows us to estimate the proportion of the population who are overweight (BMI ≥25kg/m2 to <30kg/m2) or obese (≥30kg/m2).

This indicator shows trends in obesity and overweight in adults from 1993 to 2019. The prevalence of obesity increased sharply between 1993 and 2000, with a slower rate of increase after that. In 2019, 36% of the adult population were overweight and 28% were obese.

Comparing men and women in 2019, 29% of all adult women were obese and 31% were overweight, whereas 27% of adult men were obese and 41% were overweight (data not shown).


About this data

This indicator presents findings on the prevalence of overweight and obesity for adults from the Health Survey for England and for children from the National Child Measurement Programme.

The Health Survey for England (HSE) consists of an interview at which height and weight are measured. This enables the calculation of body mass index (BMI), which is defined as weight in kilograms divided by the height in metres squared (kg/m2), a measurement which is used to define overweight or obesity. Adults were classified into the following BMI groups according to the World Health Organisation (WHO) BMI classification:

  • Underweight – less than 18.5kg/m2
  • Normal – 18.5 to less than 25kg/m2
  • Overweight, not obese – 25 to less than 30kg/m2
  • Obese, including morbidly obese - 30kg/m2 or more
  • Morbidly obese – 40kg/m2 or more

HSE data up to and including 2002 are unweighted, and from 2003 onwards data have been weighted for non-response. For more information, please see the methods report and data quality statement. The National Child Measurement Programme (NCMP) was introduced in 2006/07 and collects height and weight measurements for children in Reception (aged 4-5 years) and Year 6 (aged 10-11 years) in mainstream state schools in England. The programme now holds 13 years of data and annually measures over one million children. The national participation rate increased from 80% in 2006/07 to 95% in 2018/19.

Due to the impact of the Covid-19 pandemic, the 2020/21 collection was carried out as a sample and statistical weighting was applied to the data to produce an estimate of obesity prevalence at national level. Data quality investigations determined that weighted 2020/21 data is representative of the population and results are broadly comparable with previous years. For further information, see the National Child Measurement Programme, Summary, 2020/21. In the 2019/20 school year, data collection finished early when schools closed in March 2020 due to the Covid-19 pandemic. Data quality analysis carried out indicated that figures from 2019/20 are directly comparable with previous years. For more information, see the National Child Measurement Programme – England, 2019/20: Data Quality Statement. The HSE also collects data on childhood obesity, however as it is a sample the estimates are less precise than those for NCMP.

The BMI classification of each child is derived by calculating the child's BMI centile and classifying according to age and sex to take into account different growth patterns in boys and girls. The NCMP uses the British 1990 growth reference (UK90) to define BMI classifications. Deprivation is defined by the deprivation decile of the lower super output area of the school the child attends.

It is likely that Year 6 obesity prevalence in the first years of the NCMP (2006/07 to 2008/09) were underestimates due to low participation. This, and the impact of other improvements in data quality, should be considered when making comparisons over time. 

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