NOO data briefing
www.noo.org.uk
Adult Weight
june 2011
Key points
l In 2009 an estimated 61% of adults (aged 16 and over) were overweight or obese (Table 1). Just over
2% of adults were underweight, around the same proportion who were morbidly obese.
l Men and women have a similar prevalence of obesity, but men are more likely to be overweight
(44% compared to 33%) (Table 1).
l The prevalence of obesity in adults rose from just over 15% in 1993 to 23% in 2009 (Figure 2).
l Many of those in the obese category have a body mass index (BMI) of well over 30 (Figure 3).
There are more women than men with extremely high BMI values.
l The prevalence of obesity and overweight changes with age. Prevalence of overweight and obesity
are lowest in the 16–24 years age group, and generally higher in the older age groups among both
men and women (Figure 4).
l Among men and women, the prevalence of obesity increased across almost all social classes between
1997 and 2008 (Figure 5). Men in the skilled manual group have the highest prevalence of obesity
and those in the professional group the lowest. Women in the unskilled manual group have the
highest prevalence and once again those in the professional group have the lowest.
l Women from Black African groups appear to have the highest prevalence of obesity and men from
Chinese and Bangladeshi groups the lowest, based on the most recent data (2004). However,
research has shown that BMI may overestimate obesity among Africans and underestimate obesity in
South Asians. Using adjusted thresholds for these ethnic groups could improve obesity estimates.
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NOO data briefing: adult Weight
2
Current figures
Figure 1 and Table 1 give a detailed breakdown of weight status in recent years, based on Health Survey
for England (HSE) data. They show that in 2009 around 61% of adults were overweight or obese
(including morbidly obese); this equates to 57% of women and 66% of men. Men and women have a
similar prevalence of obesity, but men are more likely to be overweight. Women are slightly more likely
than men to be underweight, or to be obese. The adult prevalence of morbid obesity is around 2%, as is
the prevalence of underweight.
Figure 1: Adult (aged 16 and over) obesity prevalence, 2007–2009
45
Obese
40
Overweight
Proportion of adults (%)
35
30
25
20
15
10
5
0
24.0
36.7
24.5
2007
36.9
23.0
2008
38.3
2009
Year
Source: Health Survey for England
E rror bars on chart are 95% confidence intervals. These indicate the level of uncertainty about each value on the chart.
Wider intervals mean more uncertainty.
Table 1: Weight status among adults (aged 16 and over), 2007 to 2009
2007 (%)
Weight status category
Underweight
Men Women
2008 (%)
All
adults
Men Women
2009 (%)
All
adults
Men Women
All
adults
1.2
2.0
1.6
1.6
2.0
1.8
2.2
2.5
2.3
Healthy weight
33.8
41.6
37.7
32.5
41.1
36.8
32.0
40.8
36.4
Overweight
41.4
32.0
36.7
41.8
32.0
36.9
43.7
32.8
38.3
Obese
(including morbidly obese)
23.6
24.4
24.0
24.1
24.9
24.5
22.1
23.9
23.0
Source: Health Survey for England
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NOO data briefing: adult Weight
3
Trends
Figure 2 shows the changing prevalence of overweight and obesity in adults (aged 16 years and over)
since 1995 from the HSE. It shows a rise in obesity from about 15% in 1995 to just below 25% in 2009.
The rate of increase was higher between 1995 and 2001 than it has been since 2001. The HSE report
indicates that there has been no significant change since 2008 for men or women.
The prevalence of overweight has remained broadly stable during this time at 37–39%. This suggests
that roughly the same number of people have moved from the normal to the overweight category as
have moved from overweight to obese.
Figure 2: Prevalence of overweight and obesity among adults (aged 16 and over), 3-year
moving averages, 1995 to 2009
45
40
Prevalence (%)
35
30
25
20
15
Obese
10
Overweight
5
0
9
00
8
7
00
00
–2
–2
06
07
20
20
–2
6
00
5
4
00
–2
–2
05
04
20
20
03
00
–2
3
2
00
–2
02
20
20
01
00
–2
1
0
00
–2
00
20
20
99
00
9
99
–1
8
99
–2
97
98
19
19
19
–1
7
99
6
99
–1
96
95
19
19
–1
5
99
–1
94
93
19
19
Year
Source: Health Survey for England
The latest HSE report states that there are indications that the trend may be flattening out, at least
temporarily. However, it is too soon to tell whether this is the case.
Future projections1 do not indicate any flattening out of the current rising obesity trend in adults. By 2020
for men aged 20–65, projections signal a clear decline in the prevalence of healthy weight accompanied
by significant increases in the prevalence of obesity and morbid obesity. For women there is also a
projected rise in obesity and morbid obesity but to a lesser extent than for men. This is the opposite of
the current situation where morbid obesity is more common in women than in men.
1B
rown M, Byatt T, Marsh T, McPherson K (2009) A prediction of Obesity Trends for Adults and their associated diseases:
Analysis from the Health Survey for England 1993–2007. Report. London; National Heart Forum
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NOO data briefing: adult Weight
4
BMI distribution
Figure 3 shows the difference in the distribution of BMI between men and women. It combines HSE
data from three years (2007–2009) to get a more reliable picture. A higher proportion of women are
underweight or at a healthy weight compared to men, but as BMI increases the pattern changes – a
higher proportion of men than women are overweight or obese. These charts make it very clear that
many men and women have a BMI greater than the ‘healthy weight’ range (18.5 to 25). The right hand
‘tail’ (skewness) of the curve indicates the range of extremely high BMI values observed for both sexes. A
higher proportion of women than men are morbidly obese.
Figure 3: Distribution of BMI for men and women (aged 18 and over), 2007–2009
Underweight
Healthy weight
Overweight
Obese
Morbidly obese
<18.5kg/m2
18.5 to <25kg/m2
25 to <30kg/m2
30 to <40kg/m2
≥40kg/m2
Men
26.8%
Men
45.4%
Women
24.7%
Women
35.2%
Men
0.6%
Men
1.4%
Men
25.8%
Women
Women
1.1%
12
3.1%
Women
35.9%
18.5
25
30
40
BMI (kg/m )
2
Women
Source: Health Survey for England
Men
50
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NOO data briefing: adult Weight
5
Obesity and age group
Figure 4 shows how the prevalence of obesity and overweight changes with age. Prevalence of
overweight and obesity is lowest in the 16–24 age group, and generally higher in the older age groups
among both men and women. There is a decline in prevalence in the oldest age group which is especially
clear in men. A similar pattern was seen for 2008 data.
Figure 4: Prevalence of overweight and obesity, by age group, 2009
MEN
Obese
Overweight
90
Prevalence (%)
80
70
60
50
40
45.2
30
20
10
0
49.2
51.8
49.8
48.9
43.7
38.4
28.7
5.9
13.4
21.2
34.1
32.2
29.6
22.9
22.1
16–24
25–34
35–44
45–54
55–64
65–74
75+
All
Age group (years)
WOMEN
Obese
Overweight
90
Prevalence (%)
80
70
60
50
40
30
20
10
0
29.1
23.0
36.3
39.3
44.3
35.1
32.8
27.3
16.6
16.5
24.2
26.5
28.9
31.1
25.6
23.9
16–24
25–34
35–44
45–54
55–64
65–74
75+
All
Age group (years)
Source: Health Survey for England
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NOO data briefing: adult Weight
6
Obesity and social class
Figure 5 compares trends in obesity prevalence among men and women in different social classes. There
are differences between the classes in both sexes, although the disparity is much greater for women
than men. For men, the highest prevalence of obesity is found among those in social class IIIm – skilled
manual and the lowest among those in social class I – professional. For women, the highest prevalence
of obesity is found among those in social class V – unskilled manual, and the lowest once again among
those in social class I – professional. The gap between highest and lowest has widened since 1997
for both sexes. For women in social class I, the variation in obesity prevalence over the period is most
likely due to the small numbers of professional women surveyed rather than a true decrease in obesity
prevalence.
Figure 5: Obesity prevalence in adults by social class and sex, 1997–2008,
5-year moving average
MEN
35
30
Prevalence (%)
25
20
15
10
I – professional
IIIn – skilled non-manual
IV – semi-skilled manual
5
0
1997
1998
1999
2000
2001
2002
2003
2004
II – managerial technical
IIIm – skilled manual
V – unskilled manual
2005
2006
2007
2008
Year
WOMEN
40
35
30
Prevalence (%)
25
20
15
10
I – professional
IIIn – skilled non-manual
IV – semi-skilled manual
5
0
1997
1998
1999
2000
2001
2002
Year
Source: Health Survey for England
2003
2004
II – managerial technical
IIIm – skilled manual
V – unskilled manual
2005
2006
2007
2008
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NOO data briefing: adult Weight
7
Obesity and ethnicity
Figure 6 presents HSE 2004 data, which included a ‘boost sample’ from minority ethnic groups, enabling
more detailed analysis of data by ethnicity. Women from Black African groups appear to have the highest
prevalence of obesity and men from Chinese and Bangladeshi groups the lowest. Women appear to have
a higher prevalence in almost every minority ethnic group, with a significant difference between women
and men among the Pakistani, Bangladeshi and Black African groups.
However, there is ongoing debate as to whether the current criteria for defining obesity in both adults
and children are appropriate for non-European ethnic groups. BMI is not always an accurate predictor
of body fat or fat distribution in individuals. Research has shown that for the same BMI, people of
African ethnicity are likely to carry less fat and people of South Asian ethnicity more fat than the general
population. This suggests that BMI overestimates obesity among Africans and underestimates obesity in
South Asians. Using adjusted thresholds for these ethnic groups could improve obesity estimates.
These data are the most recent data on adult obesity by ethnic group and are now seven years old.
Future boosted samples are needed to make it possible to monitor trends over time in these populations.
Figure 6: Prevalence of obesity in adults (aged 16 and over) by ethnic group and sex, 2004
50
Men
45
Women
Prevalence (%)
40
35
30
25
20
15
10
5
0
23
23
General
population
25
32
Black
Caribbean
17
38
Black African
25
21
Irish
15
28
Pakistani
14
20
Indian
6
17
Bangladeshi
6
8
Chinese
Ethnic group
Source: Health Survey for England
E rror bars on chart are 95% confidence intervals. These indicate the level of uncertainty about each value on the chart.
Wider intervals mean more uncertainty.
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NOO data briefing: adult Weight
8
Data sources
Health Survey for England
All data presented here are from the HSE and were the most recent data available at the time of writing.
The HSE is a cross-sectional survey which samples a representative proportion of the population.
Timing of data collection: The survey is conducted annually. Data for some of the time series are available
from 1993 onwards. Certain years include ‘boost samples’ which focus on specific population groups:
e.g. 2004 included a boost of individuals from minority ethnic groups.
Date of next release: The report on the HSE 2010 should be published online in December 2011. The
data should be available from the UK Data Archive in the spring following publication of the report.
Definitions
Body Mass Index and weight classification in adults
BMI is a measure of weight status. BMI is a person’s weight in kilograms divided by the square of their
height in metres. The following cut-offs are used to classify adults:
BMI range (kg/m2)
Classification
Less than 18.5
Underweight
18-5–24.9
Healthy weight
25.0–29.9
Overweight
30.0–39.9
Obese
Greater than or equal to 40
Morbidly obese
In this briefing the definition ‘overweight’ does not include obese. The definition ‘obese’ includes
morbidly obese, except in Figure 3.
Useful resources
Health Survey for England
http://www.ic.nhs.uk/statistics-and-data-collections/health-and-lifestyles-related-surveys/health-surveyfor-england
http://www.dh.gov.uk/en/Publicationsandstatistics/PublishedSurvey/HealthSurveyForEngland/
Healthsurveyresults/index.htm
A prediction of Obesity Trends for Adults and their associated diseases
http://www.heartforum.org.uk/Publications_NHFreports_ObesityTrends.aspx
Statistics on Obesity, Physical Activity and Diet: England, February 2010
http://www.ic.nhs.uk/statistics-and-data-collections/health-and-lifestyles/obesity/statistics-on-obesityphysical-activity-and-diet-england-2011
Changes summary
• March 2010: Original report
• June 2011: Updated to include 2009 Health Survey for England data where available
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June 2011