# Overweight adults

Published

## 1. Main facts and figures

- in 2017/18, 62.0% of adults aged 18 and over were overweight or obese, up from 61.3% the previous year
- Black adults were the most likely out of all ethnic groups to be overweight or obese
- White British adults were also more likely than average to be overweight or obese
- adults from the Chinese ethnic group were the least likely out of all ethnic groups to be overweight or obese
- the percentage of adults in the Asian, Other White, Mixed and Other ethnic groups who were overweight or obese was also lower than the national average
- the percentage of adults who were overweight or obese was similar to 2016/17 in every ethnic group except White British, which saw an increase

## Things you need to know

The data shown here is based on the Active Lives Survey, which has been collecting data on obesity in adults since 2015/16.

Data from before 2015/16 came from the Active People Survey. Results from the two different surveys are not comparable because of differences in what was asked and how responses were collected.

The Active Lives Survey collects information from a random sample of the population to reach findings about the total population. The overall sample size is around 198,250 people each year. Data has been weighted to ONS population measures for geography and key demographics.

As with all surveys, estimates from the Active Lives Survey are subject to some uncertainty as they are based on a sample of the population. The degree of uncertainty is greater when the number of respondents is small. Therefore, the uncertainty is highest for ethnic minority groups as they usually have the smallest number of respondents.

The commentary for this data only includes reliable, or ‘statistically significant’, findings. Findings are statistically significant when we can be confident that they can be repeated and are reflective of the total population rather than just the survey sample.

Specifically, the statistical tests used mean we can be confident that if we carried out the same survey on different random samples of the population, 19 times out of 20 we would get similar findings.

Differences are statistically significant if the results for the 2 groups or time periods being compared are within entirely different ranges.

Although the percentage of Black adults who were overweight or obese appeared to fall from 72.8% in 2015/16 to 69.0% in 2016/17, and then rise again to 72.8% in 2017/18, this was not found to be reliable in significance testing.

Participants complete the Active Lives Survey online. It’s likely that all self-completion surveys elicit different results to other methods such as face-to-face interviews.

People often underestimate their weight and overestimate their height so their self-reported body mass index is known to be lower than it actually is. This measure adjusts for this bias by applying a formula based on observations from several years of the Health Survey for England, which for many respondents included both self-reported and clinically measured body mass index figures.

People whose ethnicity wasn’t known are included in the ‘All’ group. They don’t appear separately in the charts and tables.

## What the data measures

This data gives an estimate of the percentage of adults (aged 18 and older) in England who were overweight or obese, broken down by ethnicity.

The data source is Sport England’s Active Lives Survey, in which respondents were asked for their height and weight. These figures were then used to determine their body mass index (BMI), which indicates if a person is overweight or obese.

BMI is calculated by dividing a person's weight in kilograms by the square of their height in metres. Adults with a BMI of 25 or more are classed as overweight, while adults with a BMI of 30 or more are classed as obese.

The BMI figures are then adjusted using a formula that compensates for some people misrepresenting their weight when reporting it themselves.

## The ethnic categories used in this data

The data has been grouped into 7 broad ethnic categories:

- Asian
- Black
- Chinese
- Mixed
- White British
- White Other
- Other ethnicity

## 2. By ethnicity over time

2015/16 | 2016/17 | 2017/18 | ||||
---|---|---|---|---|---|---|

Ethnicity | % | Number of respondents | % | Number of respondents | % | Number of respondents |

All | 61.3 | 170,273 | 61.3 | 166,213 | 62.0 | 151,677 |

Asian | 57.9 | 6,018 | 56.3 | 6,142 | 57.0 | 4,890 |

Black | 72.8 | 1,998 | 69.0 | 1,987 | 72.8 | 1,654 |

Chinese | 36.0 | 857 | 31.5 | 873 | 34.5 | 741 |

Mixed | 54.6 | 1,529 | 57.3 | 1,616 | 58.5 | 1,568 |

White British | 62.0 | 146,869 | 62.3 | 142,038 | 62.9 | 129,957 |

White other | 57.0 | 8,610 | 57.6 | 8,678 | 57.8 | 8,340 |

Other | 58.5 | 1,191 | 59.5 | 1,084 | 58.3 | 972 |

Download table data for ‘By ethnicity over time’ (CSV) Source data for ‘By ethnicity over time’ (CSV)

### Summary

This data shows that:

- in 2017/18, 62.0% of adults aged 18 and over in England were overweight or obese, up from 61.3% the previous year
- 72.8% of Black adults were overweight or obese, the highest percentage out of all ethnic groups
- White British adults were more likely than average to be overweight or obese (at 62.9%)
- 34.5% of adults from the Chinese ethnic group were overweight or obese, the lowest percentage out of all ethnic groups
- the percentage of adults who were overweight or obese was also lower than the national average in the Asian (57.0%), Other White (57.8%) Other (58.3%) and Mixed (58.5%) ethnic groups
- percentages were broadly similar to those from 2015/16 for all ethnic groups except White British, where it increased from 62.0% to 62.9% over the 3 years covered

## 3. Methodology

The data for this measure is taken from the Active Lives Survey in 2015/16, 2016/17 and 2017/18.

The survey is carried out on behalf of Sport England by research company IPSOS-MORI.

The survey sample is randomly selected from the Royal Mail’s Postal Address File, which has a very high coverage of private residential addresses. A letter is sent to households inviting up to 2 people per household to take part in the survey, either online or by requesting a paper version of the questionnaire.

A random sampling survey design ensures results are representative of the population. 148,122 respondents aged 18 and over gave their height, weight and ethnicity in their survey response.

Because people often underestimate their weight and overestimate their height, a person’s self-reported body mass index (BMI) is generally known to be lower than it actually is. This measure adjusts for this bias by applying a formula based on observations from several years of the Health Survey for England, which for many respondents included both self-reported and clinically measured BMIs.

Weighting:

Weighting is used to adjust the results of a survey to make them representative of the population and improve their accuracy.

For example, a survey which contains 25% women and 75% men will not accurately reflect the views of the general population, which we know has an even 50/50 split.

Statisticians rebalance or ‘weight’ the survey results to more accurately represent the general population. This helps to make them more reliable.

Data has been weighted to ONS population measures for geography and key demographics.

Confidence intervals:

The confidence intervals for each ethnic group are available if you download the data.

In 2017/18, 62.0% of adults surveyed gave a height and weight that resulted in a body mass index (BMI) of 25 or more when adjusted for bias. This is a reliable estimate of the percentage of adults in England who were overweight. However, because Active Lives Survey results are based on a random sample of adults aged 18 or older, it’s impossible to be 100% certain of the true percentage. It’s 95% certain that somewhere between 61.7% and 62.2% of all adults in England were overweight or obese. In statistical terms, this is a 95% confidence interval. This means that if 100 random samples were taken, then 95 times out of 100 the estimate would fall in this range (between the upper and lower confidence interval). But 5 times out of 100 it would fall outside this range. The smaller the survey sample, the more uncertain the estimate and the wider the confidence interval. For example, the number of people from the Chinese ethnic group sampled for this survey is relatively small, so we can be less certain about the estimate for the smaller group. This greater uncertainty for people from the Chinese ethnic group is expressed by the wider confidence interval of between 31.2% and 37.9%.

Statistically significant differences have been determined where the 95% confidence intervals of an ethnic group do not overlap with the national average or with that of the ethnic group being compared. This is a pragmatic but less precise test of the significance of differences between estimates. It is possible that a finding may be significant when confidence intervals overlap slightly.

For further details of the sampling method, weighting and confidence intervals see the Active Lives Survey technical report (PDF).

### Rounding

Data is rounded to 1 decimal point in charts and tables, and unrounded in the data download.

Quality and methodology information

## 4. Data sources

### Source

### Type of data

Survey data

### Type of statistic

Official statistics

### Publisher

Sport England

### Publication frequency

Twice a year

### Purpose of data source

The Active Lives Survey measures the number of people aged 16 and over who take part in sport and physical activity.

This data informs the government’s strategy on physical activity, Sporting Future, which looks at 5 aspects of physical activity:

- physical well-being
- mental well-being
- individual development
- social and community development
- economic development

### Secondary source

Public Health Outcomes Framework

### Type of data

Survey data

### Type of statistic

Official statistics

### Publisher

Public Health England

### Publication frequency

Yearly

## 5. Download the data

Measure, Ethnicity, Ethnicity_Type, Time, Time_Type, Geography, Geography_Type, Geography_Code, Gender, Age, Value, Value_Type, Denominator, Confidence intervals