Epidemiology · Vol. 1, No. 1 · 2016 · pp. 20–32 · e-ISSN 2473-4780

Geography of Diet in the UK Women’s Cohort Study: A Cross-Sectional Analysis

Michelle A. Morris, Graham P. Clarke, Kimberley L. Edwards, Claire Hulme, Janet E. Cade

Leeds Institute for Data Analytics, University of Leeds, Leeds, LS2 9JT, UKUnited Kingdom
School of Geography, University of Leeds, Leeds, LS2 9JT, UKUnited Kingdom
Centre for Sports Medicine, School of Medicine, University of Nottingham, Queens Medical Centre, Nottingham, NG7 2UH, UKUnited Kingdom
Academic Unit for Health Economics, Leeds Institute of Health Sciences, University of Leeds, LS2 9JT, UKUnited Kingdom
Nutritional Epidemiology Group, School of Food Science and Nutrition, University of Leeds, Leeds, LS2 9JT, UKUnited Kingdom

DOI: https://doi.org/10.17140/epoj-1-104 · Published 2016-03-21 · Licence: https://creativecommons.org/licenses/by/4.0 · © 2016 The Author(s)

Abstract

Diet can influence health outcomes and chronic disease risk, therefore a better understanding of factors influencing diet is important in promotion of healthier dietary choices. Many factors influence food choice, including the environment in which we live. This study aims to explore differences in dietary pattern consumption by two spatial measures: Government Office Region (a large regional unit of geography) and Output Area Classification (a small area geography combined with demographic characteristics). A cross-sectional analysis using data from the UK Women’s Cohort Study was carried out. This cohort included ~35000 middle aged women recruited between 1995 and 1999. Dietary patterns were derived using a k-means cluster analysis from diet data collected using a validated 217 item Food Frequency Questionnaire. Multinomial logit regression was used to test whether the area in which the women live, predicts their dietary pattern consumption. Results show that dietary patterns vary significantly by both spatial measures. The Government Office Region, the North West of England has the highest proportion of individuals consuming the least healthy, monotonous diets, while Greater London has the highest proportion of vegetarian diets. Individuals living in Super groups ‘Countryside’ and ‘Prospering Suburbs’ consume healthier, more diverse diets. Those in ‘Constrained by Circumstance’ and ‘Blue Collar Communities’ consume monotonous, less healthy diets. Using a combination of spatial scales such as Government Office Region and Output Area Classification Supergroup could have a beneficial impact on targeting of public health dietary interventions and subsequent health.

Keywords: Dietary pattern; Diet; Geodemographic classification; Geography; Region; UK women’s cohort study; Public health

Methods

Study Design and Sample

At baseline, between 1995 and 1998, 35,372 women

were recruited into the UKWCS on a volunteer basis from

a World Cancer Research Fund (WCRF) mailing list. The re-

sponse rate was 58%, from 61,000 invitations to take part. These

women all completed at baseline first contact, a 217 item vali-

7 17 dated,17 Food Frequency Questionnaire (FFQ), aiming to assess

usual diet over the past 12 months, along with a more general

questionnaire. It was not possible to assign a dietary pattern to

all women due to some providing incomplete FFQs and there-

fore 1902 women were excluded from the sample. Individuals

consuming <500 and >6000 kcal/day were excluded from the

analysis as these were considered to be outliers (n=70). A valid

postcode was not available for all these women, so following 13-15

data cleaning these 1128 women were excluded. Finally, 62

women living in Northern Ireland were also excluded due to in-

sufficient numbers in this area for meaningful analysis. This left

a sample of 32,205 for cross-sectional dietary pattern analysis.

Ethics

Ethical approval was obtained from 174 National

Health Service (NHS) local research ethics committees during

1994 and 1995.

Dietary patterns

The dietary patterns in the UKWCS were identified in

a previous study by Greenwood et al.7 Seven dietary patterns

were identified from FFQ data using a k-means cluster analy-

sis. The patterns were named to reflect the types and quantities

of food consumed in each pattern. The patterns are as follows:

“Monotonous Low Quantity Omnivore” – a diet high in white

bread, sugar and milk; “Health Conscious” – a diet high in fruit

and vegetables and wholegrains; “Traditional Meat Chips and

Pudding Eater” – typified by a white bread, meat, chips and

high fat, creamy foods; “Conservative Omnivore” – a diet lack-

ing high quantities of any food, but with moderate quantities

of most foods, especially potatoes, meat, fish, eggs, fruit and

vegetables; “Higher Diversity Traditional Omnivore” – a diet

similar to the Traditional Meat Chips and Pudding eater but with

higher diversity; “Low Diversity Vegetarian” – a meat free diet

high in wholemeal bread, soya, pulses, fruit and vegetables; and

“High Diversity Vegetarian” – a meat free diet with lots of va-

riety including wholemeal bread, cereals, wholemeal pasta and

rice, soya, spreads, nuts, pulses, fruit, vegetables and more (see

Appendix A - Summary of dietary patterns for more details of

the dietary patterns). The “Health Conscious” dietary pattern is

the healthiest pattern and the “Monotonous Low Quantity Om-

nivore” the least healthy. The healthiness of the dietary patterns

was determined by scoring each pattern against the UK dietary

recommendations ‘The Eatwell Plate’.

Spatial scale

This study first reports diet according to the nine GORs

of England. Scotland and Wales are included as entire countries

(without further regional breakdown). Northern Ireland has not

been included (as described above). Therefore 11 regions are

presented. The OAC20 is used for the geodemographic analysis.

This classification has been created using the geographical unit

Output Area – which consists of a minimum of 40 households

and contains an average of 250 people – combined with 41 vari-

ables reported in the 2001 census. This was the census closest in

time to the majority of the UKWCS data collection. OAC is a

three tier classification. The first tier are named ‘Supergroups’ of

which there are seven. The second tier ‘Groups’ of which there

are 21 and the third tier ‘Subgroups’ of which there are 52. The

OAC categories were generated using an adapted k-means clus-

tering procedure.20 Results at Supergroup level are presented in

this paper. The seven OAC Supergroups are as follows: ‘Blue

Collar Communities’ – typified by living in terraced accommo-

dation, presence of young children and routine or semi-routine

employments along with those working in manual labour type

roles; ‘City Living’ – typically including high proportions of

adults aged 25-44, large numbers of individuals born outside

of the UK, single person rented houses or flats and many in or

holding higher education qualifications; ‘Countryside’ – this

groups contains high proportions of adults aged over 45 years

old, living in detached housing with two or more cars in the

household. Many work from home, provide unpaid care or work

in agriculture; ‘Prospering Suburbs’ – many aged 45-64 living

as two adults and no children reside in these areas. There are

non-dependent children living in these areas in mostly detached

housing with two or more cars per household; ‘Constrained by

circumstance’ – this Supergroup is typified by individuals living

in care homes, or public provided accommodation, as such there

are many divorced or separated, single pensioners, or lone par-

ent households and those who are unemployed or with limiting

long-term illness; ‘Typical Traits’ – this groups contains those

with most average characteristics; and ‘Multicultural’ – this

group has high proportions of those born outside the UK with

a range of different ethnicities. Many will use public transport

or be unemployed (see Appendix B – Summary of OAC Super-

groups for more information).

GOR and OAC were assigned via the postcode unit for

each woman in the cohort, using the geoconvert tool.21

Covariates

Metabolic Equivalent of Tasks (METs) were used as

a measure of physical activity, calculated by assigning a value

from the Compendium of Physical Activities22 to the results of

questions asked at baseline where the women reported hours per

typical week spent in various common activities. Smoking is re-

ported as a binary value which indicates if the woman was a cur-

rent smoker at baseline. Total calorie intake, including calories

from alcohol, is derived from the FFQ. Age, social class and

education were collected in the UKWCS baseline lifestyle ques-

tionnaire.

Statistical analysis

STATA IC 12.1 statistical software has been used for

the analysis.23 Chi squared statistics are used to detect differ-

ences across categories for tabulated data.

Multinomial logit regression was carried out for the

categorical data. The regression analysis looked at the likeli-

hood of consuming a particular dietary pattern compared to the

“Traditional Meat Chips and Pudding Eater” pattern (the most

commonly consumed in the UKWCS) accounting for place of

residence. In the regional analysis the region of residence was

compared to living in the South East, (where the majority of the

UKWCS women reside). The geodemographic analysis com-

pared the Supergroup which the women live in with women liv-

ing in the Typical Traits Supergroup (named since those residing

in such areas are average with respect to the demographic vari-

ables used to create the classification). Results are presented as

Relative Risk Ratios (RRRs) with 95% confidence intervals and

p values.

Regression models are adjusted to account for potential

confounders which were identified using a causal diagram. The

adjusted regression model includes physical activity, smoking

and total calorie intake including alcohol, age, social class and

education. The composition characteristics – age, social class

and education – were not adjusted for in the analysis with OAC

(Table 2) as this would have over adjusted these characteristics

as they are included in the OAC already.

Results

Summary statistics

The UKWCS mean age was 52.2 years (SD 9.3) with

means ranging between 51.4 to 53.0 years by region and 50.1

to 53.4 years by OAC Supergroup. Physical activity, measured

using METS calculated from a physical activity questions for a

24 hour period had a mean value of 16.0 METS (SD 11.7); mean

regional range 16.4 to 17.8; OAC Supergroup range 15.0 to 18.2.

Sixty-five percent of the cohort had a professional/managerial

occupation with a regional range of 58-67% and OAC Super-

group range of 53-73%, with highest numbers in the City Living

Supergroup and lowest in the Blue Collar Communities. Fifty-

two percent of the cohort were educated to A-level (school year

13) or above with a regional range of 46-65% and OAC Super-

group range 37-70% with lowest values in the ‘Constrained by

Circumstance’ and ‘Blue Collar Communities’ and highest again

in ‘City Living’.

A wider variation in the mean characteristics of the

women is evident when grouped by OAC Supergroup compared

to grouping by region. This supports the expectation that incor-

porating demographic variables into a geographical classifica-

tion enhances understanding of specific populations, rather than

seeing averaged out characteristics of a much larger geographi-

cal region.

Regional analysis

The distribution of the UKWCS as a percentage of the

total UK population of women, by region, ranges from 0.08%

for the North East, North West and Scotland and 0.17% for

the South East and South West (with other regions falling in-

between). So whilst the lowest number of cohort women reside

in the North East, this is also the region which has the lowest

population in the whole UK. The dietary pattern consumption

vary significantly across regions (p=0.002), with the exception

of the Health Conscious dietary pattern (Figure 1), however, dif-

ferences are small.

Results from a multinomial regression analysis (Table

1), for dietary pattern consumption by region, identify that some

regions are more likely to consume certain dietary patterns over

Figure 1
Figure 1. Percentage of UKWCS consuming each dietary pattern by GOR.

others. However, the regression results show that no region has

overall better dietary habits than another. Greater London high-

lights how one region can exhibit statistical significance in rela-

tive risk ratio (RRR) of being more likely to consume “Health

Conscious” (most healthy) and also more likely to consume a

“Monotonous Low Quantity Omnivore” (least healthy)19 diet

compared to the “Traditional Meat, Chips and Pudding Eater”

pattern, which was the reference group, showing that both ex-

tremes of dietary patterns reside in the same region. While some

regions show a significant increased likelihood of consuming a

poor “Monotonous Low Quantity Omnivore” dietary pattern; for

example, Wales, Yorkshire and the Humber, North West; these

regions are, however, not significantly less likely to consume

a “Health Conscious” dietary pattern which would make it dif-

ficult to know where to precisely target healthy dietary pattern

promoting interventions.

These observations remain true when the model is ad-

justed for physical activity and energy intake and smoking and

for demographic characteristics; age, social class and education

and show much the same results, in some cases slightly accen-

Monotonous Low Health Meat Chips

Quantity Omnivore Conscious and Pudding

RRR (95% CI) RRR (95% CI) RRR (95% CI) RRR (95% CI) RRR (95% CI) RRR (95% CI)

p value p value

0.87(0.70 to 1.08) 0.82(0.61 to 1.12) 0.79(0.63 to 0.99) 0.62(0.49 to 0.77) 0.64(0.51 to 0.81) 0.84(0.67 to 1.06) North East 1.00 p=0.211 p=0.218

1.20(1.04 to 1.38) 0.91(0.75 to 1.12) 0.81(0.69 to 0.94) 0.85(0.73 to 0.98) 0.84(0.73 to 0.98) 0.83(0.71 to 0.98) North West 1.00 p=0.013 p=0.368

Yorkshire and 1.11(0.95 to 1.30) 0.97(0.78 to 1.20) 1.07(0.92 to 1.25) 0.96(0.83 to 1.12) 0.90(0.77 1.06) 0.99(0.84 to 1.17)

the Humber p=0.179 p=0.776

1.01(0.85 to 1.18) 1.15(0.93 to 1.42) 1.07(0.91 to 1.25) 1.13(0.97 to 1.32) 0.92(0.78 to 1.09) 1.00(0.84 to 1.19) East Midlands 1.00 p=0.944 p=0.209

1.07(0.92 to 1.25) 1.05(0.85 to 1.30) 0.88(0.75 to 1.04) 1.03(0.89 to 1.19) 0.82(0.70 to 0.97) 0.96(0.81 to 1.13) West Midlands 1.00 p=0.384 p=0.652

East of 0.89(0.76 to 1.03) 0.92(0.75 to 1.12) 0.94(0.81 to 1.09) 0.98(0.85 to 1.12) 0.89(0.77 to 1.03) 0.89(0.76 to 1.05)

England p=0.115 p=0.407

Greater 1.42(1.23 to 1.64) 1.38(1.14 to 1.67) 0.89(0.76 to 1.05) 1.28(1.12 to 1.48) 1.77(1.54 to 2.04) 1.64(1.41 to 1.90)

London p<0.001 p=0.001

South East 1.00 1.00 1.00

1.01(0.89 to 1.16) 1.15(0.96 to 1.38) 1.11(0.97 to 1.27) 1.04(0.92 to 1.19) 0.99(0.86 to 1.13) 1.20(1.04 to 1.38) South West 1.00 p=0.837 p=0.120

0.84(0.71 to 0.99) 1.11(0.90 to 1.37) 0.97(0.82 to 1.14) 0.77(0.65 to 0.90) 0.66(0.56 to 0.78) 0.84(0.70 to 1.00) Scotland 1.00 p=0.039 p=0.329

1.25(1.03 to 1.51) 1.19(0.92 to 1.55) 0.89(0.72 to 1.10) 1.08(0.89 to 1.31) 0.98(0.80 to 1.20) 1.11(0.90 to 1.37) Wales 1.00 p=0.027 p=0.187

Adjusted model (adjusting for smoking, total calorie intake including alcohol, typical daily physical activity (METs), age, social class, education) (pseudo R = 0.12)

1.14(0.89 to 1.47) 0.77(0.56 to 1.06) 0.71(0.56 to 91) 0.71(0.55 to 0.91) 0.67(0.53 to 0.86) 0.74(0.58 to 0.95) North East 1.00 p=0.303 p=0.107

1.48(1.25 to 1.74) 0.91(0.73 to 1.12) 0.76(0.64 to 0.90) 0.95(0.81 to 1.11) 0.90(0.77 to 1.06) 0.81(0.68 to 0.96) North West 1.00 p<0.001 p=0.368

Yorkshire and 1.27(1.06 to 1.53) 0.95(0.75 to 1.20) 1.03(0.87 to 1.23) 1.05(0.89 to 1.25) 0.92(0.77 to 1.09) 0.96(0.80 to 1.15)

the Humber p=0.009 p=0.676

1.09(0.90 to 1.32) 1.10(0.87 to 1.38) 1.07(0.90 to 1.28) 1.19(1.00 to 1.41) 0.95(0.80 to 1.14) 0.96(0.80 to 1.15) East Midlands 1.00 p=0.363 p=0.429

1.16(0.97 to 1.38) 1.02(0.81 to 1.27) 0.86(0.72 to 1.03) 1.01(0.85 to 1.19) 0.79(0.66 to 0.94) 0.91(0.76 to 1.09) West Midlands 1.00 p=0.105 p=0.879

East of 0.90(0.76 to 1.07) 0.96(0.77 to 1.20) 1.00(0.85 to 1.17) 0.98(0.84 to 1.14) 0.84(0.07 to 0.99) 0.91(0.77 to 1.08)

England p=0.229 p=0.721

Greater 1.23(1.04 to 1.45) 1.37(1.11 to 1.68) 0.89(0.75 to 1.05) 1.14(0.97 to 1.33) 1.46(1.26 to 1.70) 1.45(1.23 to 1.70)

London p=0.015 p=0.003

South East 1.00 1.00 1.00

1.07(0.92 to 1.25) 1.09(0.90 to 1.32) 1.11(0.96 to 1.29) 1.01(0.87 to 1.17) 0.99(0.85 to 1.14) 1.18(1.01 to 1.37) South West 1.00 p=0.392 p=0.381

1.06(0.88 to 1.28) 0.89(0.71 to 1.11) 0.80(0.67 to 0.96) 0.83(0.70 to 0.99) 0.63(0.53 to 0.76) 0.68(0.56 to 0.81) Scotland 1.00 p=0.550 p=0.305

1.49(1.31 to 1.69) 1.06(0.80 to 1.41) 0.77(0.61 to 0.97) 1.15(0.93 to 1.43) 1.00(0.81 to 1.25) 0.97(0.78 to 1.22) Wales 1.00 p=0.002 p=0.670

Table 1. Regression models investigating whether Government Office Region predicts dietary patterns displaying Relative Risk Ratio (95% Confidence Interval) and p value.

Traditional Higher Diversity Conservative Low Diversity High Diversity Traditional Omnivore Vegetarian Vegetarian

Omnivore Eater

Ref.

p value p value p value p value

Unadjusted model (pseudo R =0.003)

p=0.043 p<0.001 p<0.001 p=0.149

p=0.006 p=0.023 p=0.025 p=0.024

1.00 p=0.392 p=0.646 p=0.199 p=0.873

p=0.444 p=0.123 p=0.340 p=0.997

p=0.135 p=0.713 p=0.019 p=0.610

1.00 p=0.400 p=0.736 p=0.124 p=0.169

1.00 p=0.165 p<0.001 p<0.001 p<0.001

1.00 1.00 1.00 1.00

p=0.142 p=0.528 p=0.847 p=0.011

p=0.688 p=0.001 p<0.001 p=0.046

p=0.300 p=0.417 p=0.817 p=0.327

p=0.006 p=0.007 p=0.002 p=0.019

p=0.001 p=0.525 p=0.206 p=0.016

1.00 p=0.712 p=0.571 p=0.323 p=0.636

p=0.433 p=0.046 p=0.590 p=0.658

p=0.094 p=0.949 p=0.008 p=0.316

1.00 p=0.987 p=0.764 p=0.038 p=0.270

1.00 p=0.178 p=0.107 p<0.001 p<0.001

1.00 1.00 1.00 1.00

p=0.157 p=0.909 p=0.860 p=0.032

p=0.014 p=0.044 p<0.001 p<0.001

p=0.026 p=0.194 p=0.988 p=0.823

tuated. The pseudo R2 value shows that the adjusted model ex-

plains 12% of variation in dietary pattern, compared to less than

1% in the unadjusted model. Most of this variation is explained

by the energy intake adjustment.

Geodemographic analysis

The UKWCS comprises women from each of the seven

OAC Supergroups, with some over-representation in the ‘Pros-

pering Suburbs’ and ‘Countryside’ and under-representation in

the ‘Constrained by Circumstance’, ‘Blue Collar Communities’

and ‘Multicultural’ Supergroups (Figure 2). This is as expected

in a predominantly middle class cohort of women. That said,

Figure 2
Figure 2. UKWCS compared to the UK population, by OAC Supergroup.
Figure 3
Figure 3. Percentage of UKWCS women consuming each dietary pattern by OAC Supergroup.

there are still large numbers in each of the Supergroups.

Significant variation for consumption of all dietary pat-

terns by OAC Supergroup is observed (Figure 3). In general,

variation is wider when considering differences by geodemo-

graphic Supergroup compared to by region, suggesting that the

inclusion of demographic variables with geography could tell us

something more interesting about dietary patterns.

The multinomial regression model (Table 2) shows that

OAC Supergroup has a significant relationship with dietary pat-

tern consumption. The unadjusted model shows that the ‘Con-

strained by Circumstance’ group have a significantly elevated

RRR of 1.33 (95% CI 0.11 to 1.59) for consuming the least

healthy, “Monotonous Low Quantity Omnivore” dietary pat-

tern whilst also having a significantly lower RRR for consuming

the two most healthy dietary patterns, the “Health Conscious”

(RRR=0.69 95% CI 0.51 to 0.93) and the “Higher Diversity Tra-

ditional Omnivore” (RRR=0.74 95% CI 0.59 to 0.92). The oppo-

site is observed for the ‘Countryside’ Supergroups who have an

increased likelihood of consuming the healthy patterns (“Health

Conscious” RRR=1.33 95% CI 1.14 to 1.55 and “High Diversity

Traditional Omnivore” RRR=1.37 95% CI 1.21 to 1.54) and de-

creased likelihood of consuming the unhealthiest, “Monotonous

Low Quantity Omnivore” pattern (RRR=0.76 95% CI 0.68 to

0.86).

The adjusted model accounts for total energy intake

Monotonous Higher Diversity

Low Quantity Health Conscious Traditional

Omnivore Omnivore

Rrr(95% Ci) Rrr(95% Ci) Rrr(95% Ci) Rrr(95% Ci) Rrr(95% Ci) Rrr(95% Ci

p value p value

Blue Collar 1.16(1.00 to 1.36) 0.87(0.69 to 1.10) 0.81(0.68 to 0.97) 0.87(0.74 to 1.02) 0.65(0.55 to 0.78) 0.57(0.47 to 0.69)

Communities p=0.054 p=0.206

1.05(0.88 to 1.26) 1.55(1.23 to 1.95) 1.05(0.87 to 1.28) 1.36(1.14 to 1.61) 1.56(1.32 to 1.84) 1.59(1.33 to 1.89) City Living 1.00 p=0.587 p<0.001

0.76(0.68 to 0.86) 1.33(1.14 to 1.55) 1.37(1.21 to 1.54) 1.15(1.03 to 1.29) 0.79(0.71 to 0.89) 0.97(0.86 to 1.09) Countryside 1.00 p<0.001 p<0.001

Prospering 0.76(0.69 to 0.84) 0.90(0.78 to 1.04) 1.10(0.99 to 1.23) 0.96(0.87 to 1.06) 0.59(0.53 to 0.65) 0.66(0.59 to 0.73)

Suburbs p<0.001 p=0.144

Constrained 1.33(0.11 to 1.59) 0.69(0.51 to 0.93) 0.74(0.59 to 0.92) 0.91(0.75 to 1.10) 0.71(0.58 to 0.86) 0.67(0.54 to 0.83) by 1.00 p=0.002 p=0.015 Circumstance

Typical Traits 1.00 1.00 1.00

1.23(1.02 to 1.47) 1.16(0.90 to 1.49) 0.93(0.76 to 1.15) 1.09(0.91 to 1.32) 1.70(1.43 to 2.01) 1.55(1.29 to 1.86) Multicultural 1.00 p=0.027 p=0.260

Adjusted model(adjusting for smoking, total calorie intake including

Blue Collar 1.25(1.06 to 1.48) 0.79(0.62 to 1.00) 0.72(0.60 to 0.87) 0.95(0.80 to 1.12) 0.70(0.59 to 0.83)

Communities p=0.009 p=0.050

0.88(0.73 to 1.07) 1.66(1.32 to 2.10) 1.10(0.90 to 1.34) 1.24(1.04 to 1.48) 1.48(1.25 to 1.75) City Living 1.00 p=0.208 p<0.001

0.79(0.69 to 0.89) 1.3(1.12 to 1.53) 1.35(1.20 to 1.53) 1.14(1.01 to 1.28) 0.79(0.70 to 0.89) Countryside 1.00 p<0.001 p=0.001

Prospering 0.77(0.69 to 0.86) 0.91(0.79 to 1.06) 1.11(1.00 to 1.25) 0.94(0.85 to 1.05) 0.58(0.52 to 0.64)

Suburbs p<0.001 p=0.215

Constrained 1.40(1.16 to 1.71) 0.66(0.49 to 0.90) 0.69(0.55 to 0.86) 0.98(0.80 to 1.20) 0.75(0.61 to 0.92) by 1.00 p=0.001 p=0.008 Circumstance

Typical Traits 1.00 1.00 1.00

0.99(0.82 to 1.21) 1.24(0.96 to 1.60) 0.98(0.79 to 1.21) 0.99(0.82 to 1.20) 1.62(1.36 to 1.92) Multicultural 1.00 p=0.951 p=0.107

Table 2. Regression models investigating whether OAC Supergroup predicts dietary patterns displaying Relative Risk Ratio (95% Confidence Interval) and p value.

and physical activity in order that observed effects can be as-

sumed to be dietary pattern related and not due to the volume of

energy intake or expenditure. Other variables, such as age, edu-

cation and social class, which could be considered as confound-

ers have not been adjusted for, as these variables are included in

assignment of the OAC.

In the adjusted model, the relationships observed in the

unadjusted models are unaffected when additionally adjusting

for smoking, total calorie intake including alcohol, typical dai-

ly physical activity (METs), age, social class, education. They

are in fact accentuated for the “Constrained by Circumstance”

group (in comparison to the reference group “Traditional Meat,

Chips and Pudding Eaters”: “Monotonous Low Quantity Omni-

vore” diet RRR=1.40 95% CI 1.16 to 1.71, “Health Conscious”

Traditional

Meat Chips Conservative Low Diversity High Diversity

and Omnivore Vegetarian Vegetarian

Pudding Eater

Ref.

p value p value p value p value

Unadjusted model(pseudo R =0.007)

1.00 p=0.022 p=0.095 p<0.001 p<0.001

p=0.611 p=0.001 p<0.001 p<0.001

p<0.001 p=0.016 p<0.001 p=0.582

1.00 p=0.083 p=0.444 p<0.001 p<0.001

p=0.008 p=0.330 p=0.001 p<0.001

1.00 1.00 1.00 1.00

p=0.524 p=0.360 p<0.001 p<0.001

alcohol and typical daily physical activity(METs)(pseudo R =0.10)

1.00 0.55(0.05) p<0.001 p=0.001 p=0.526 p<0.001

1.64(0.15) p<0.001 p=0.349 p=0.019 p<0.001

0.95(0.06) p=0.386 p<0.001 p=0.029 p<0.001

1.00 0.65(0.04) p<0.001 p=0.052 p=0.259 p<0.001

0.66(0.08) p<0.001 p=0.001 p=0.859 p=0.005

1.00 1.00 1.00 1.00

1.65(0.15) p<0.001 p=0.839 p=0.938 p<0.001

RRR=0.66 95% CI 0.49 to 0.90, “Higher Diversity Traditional

Omnivore” RRR=0.69 95% CI 0.55 to 0.86). The ‘Blue Col-

lar Communities’ also show the same convincing pattern (in

comparison to the reference group “Traditional Meat, Chips and

Pudding Eaters”: “Monotonous Low Quantity Omnivore” diet

RRR=1.25 95% CI 1.06 to 1.48, “Health Conscious” RRR=0.79

95% CI 0.62 to 1.0, “Higher Diversity Traditional Omnivore”

RRR=0.72 95% CI 0.60 to 0.87).

Interestingly, in both the unadjusted and adjusted mod-

els, the ‘City Living’ and ‘Multicultural’ Supergroups are ap-

proximately 50% more likely to consume a vegetarian diet, with

other Supergroups less likely, compared to the reference ‘Typi-

cal Traits’ Supergroup.

The pseudo R2 value indicates 10% of variation in di-

etary pattern is explained by the model. This is similar to that

shown in the adjusted model using GOR.

Discussion

Variations in dietary pattern consumption are observed

both regionally and according to the geodemographic Super-

group in which the women live. These variations occur both

within a dietary pattern across the Regions and Supergroups and

also between dietary patterns within a Region or Supergroup.

Analysis using a geodemographic classification provides more

insight into spatial variations in dietary pattern in the UKWCS

than analysis using GOR whilst controlling for certain demo-

graphic characteristics.

Results suggest an association between a healthy diet –

illustrated by the “Health Conscious” dietary pattern and dietary

diversity, illustrated by the “Higher Diversity Traditional Omni-

vore” – and being a member of the more affluent OAC groups.

This is supportive of other research suggesting that a healthy diet

is more expensive and therefore restricted by financial ability.24

The Family Spending report from the Living Costs and Food

Survey25 indicates that the OAC Supergroups ‘Countryside’ and

‘Prospering Suburbs’ spend the most on food per week, which

is also in line with our findings based on the assumption that a

healthier diet is a more expensive one.

Unlike earlier studies using fruit and vegetable intake

as a proxy measure of a healthy diet,12 in this study the “Health

Conscious” dietary pattern incorporates more dietary compo-

nents than just fruit and vegetable intake to represent dietary

healthiness.A full spectrum of dietary diversity is also represent-

ed by the dietary patterns (as indicated by the pattern names).

High dietary diversity appears to be associated with living in

more affluent OAC Groups, and conversely dietary monotony

correlates with the poorer areas. A conservative dietary pattern

and the traditional dietary pattern have slightly higher concen-

trations in the deprived areas.

Summary characteristics for the UKWCS vary little by

er, when the same characteristics are presented by OAC Super-

group variation is greater. The OAC uses variables such as age,

occupation and education, as collected in the census. No infor-

mation relating to diet is included in the census or the OAC, yet

increased variation in dietary patterns by OAC rather than GOR

is observed supporting evidence that socio-demographic charac-

teristics influence diet,26 but also that small area geography – the

immediate local environment – influences diet.27 Using the small

geographic unit of Output Area (containing approximately 250

individuals) compared to the large geographical unit of a GOR

(containing millions of individuals) produces results which will

be much more relevant at a local area level.

Strengths And Limitations

The UKWCS, specifically designed to investigate the

effect of dietary patterns on health outcomes, provides quality

dietary data for analysis. Vegetarians were deliberately over

sampled and as such make up a higher proportion in this co-

hort than in the general population. This means that this study

is powered sufficiently to detect differences between different

types of diet which is a strength of the design. Measurement of

diet is subject to a range of potential bias including under or over

reporting. Collecting information from a sample which is large

enough to be generalisable to a given population is also chal-

lenging due to temporal and financial constraints, making this

study a valuable resource.

Geographic location of participants was not a design

factor for the UKWCS, so despite large numbers in each of

the nine GORs of the England and Scotland and Wales these

regions are not equally represented across the cohort. The low-

est numbers (n=957) were observed residing in the North East.

However, when considering this in the context of other dietary

survey information, this is a large number of women on which

to base robust analysis. The National Diet and Nutrition Survey

(NDNS), for example, whilst it was designed to be geographi-

cally representative, only includes 3073 individuals in total

(from the three year rollout) of which only about one quarter are

women. The UKWCS sample is approximately 40 times the size

of that national sample of women.

Recruitment of the UKWCS was on a volunteer basis

from a WCRF mailing list of previous questionnaire partici-

pants so it may be expected that there is some volunteer bias.

The women are predominantly middle age, middle class and

white. This may account for the over representation observed

when comparing the UKWCS to the whole UK population, in

the ‘Countryside’ and ‘Prospering Suburbs’ Supergroups which

are characterised by middle age, more middle class, white indi-

viduals with larger detached houses. Under representation is ob-

served in ‘Blue Collar Communities’, ‘Constrained by Circum-

stance’ and ‘Multicultural’ Supergroups. Despite this there are

large numbers of women in each of the seven OAC Supergroups,

sufficient to provide confidence in the associations observed in

this study.

The dietary patterns used, whilst data driven, are not

necessarily comparable to dietary patterns used in other surveys.

That said, they provide a comprehensive illustration of dietary

patterns consumed in the UK. Comparing these to another data

driven but not international classification, such as the OAC could

be considered subjective, but this paper illustrates how different

spatial measures can be useful in public health and specifically

dietary research, rather than critique dietary patterns or geode-

mographic classifications.

For some geodemographic classifications, created by

market research companies, the methods used to generate the

classification are not transparent as these are the intellectual

property of the company. This can be a limitation for use in re-

search as it can make adjustment for confounding a guessing

game. However, the methods used to generate the OAC are re-

ported in full, allowing for researchers to have clear insight into

the classification data they are using.

The OAC groups include all of the UK population who

completed the Census questionnaire, so incorporate men and

children in addition to women. Whilst the NDNS reports statisti-

cal differences between the food consumed by men and women

(stratified both by region and whether or not the individuals are

in receipt of benefits)28 it has not specifically reported whether

there was a difference in the diets of men and women within the

same household in the UK. With this in mind, the results of this

study can only reliably be applied to women.

The dietary data used in this study were collected in the

late 1990s. It is feasible that dietary habits could have changed

since this time. However it is rare that dietary information of this

quality is collected in such a large sample in the UK. Prospective

dietary data collection is essential when considering influence

on diseases with a latent development period, such as cancer.

Collection dietary records for cancer cases can impact on subject

recall of their diet.2 Therefore the application of these results

with respect to the effect of diet on health is relevant, despite

possible dietary change since the data was collected.

This study uses the UK as a case study. However, the

methods are transferable elsewhere and it would be possible to

carry out the same sort of analysis for other countries for which

geodemographic classifications have been generated. An exam-

ple, Callcredit group have generated geodemographic classifica-

tions for 40 countries worldwide.29

Policy Implications

Dietary pattern variation between regions, with the ex-

ception of the “Health Conscious” dietary pattern (p=0.186), is

statistically significant (p<0.01). Such variation at a large geo-

graphical scale is suggestive that there are regional influences on

eating habits, not just that of the local surrounding area. Further

investigation could be carried out into this regional variation;

however, it may be erroneous to ascribe specific factors to a par-

nating influence on the dietary pattern. The regression analysis

using region, including demographic variables, shows that some

regions have significant RRRs of consuming a particular dietary

pattern. For example Greater London has significantly increased

risk, compared to those living in the South East, of consuming

both the “Health Conscious” (most healthy) and the “Monoto-

nous Low Quantity Omnivore” (least healthy) diet (compared

to consuming the traditional diet). Observations like this mean

that implementing a cost effective nutritional intervention at the

regional level would be extremely difficult.

However, when we consider dietary pattern variation

by geodemographic Supergroup the results present a clearer pic-

ture. Those living in a ‘Blue Collar Community’, for example

have significantly increased risk of consuming the “Monotonous

Low Quantity Omnivore” (least healthy) dietary pattern and a

significantly reduced risk of consuming the “Health Conscious”

and “High Diversity Traditional Omnivore” (two most healthy)

dietary patterns, suggesting that it would be worthwhile imple-

menting a healthy diet promotion in these types of areas. The re-

gional regression model, controlling for age and education does

not produce such clear results and the regression models using

geodemographic Supergroups, indicating that the small scale ge-

ography combined with a number of demographic variables is a

powerful tool. Combination of both the regional and Supergroup

results could help to target interventions to certain types of areas

within the region most at risk of consuming a poor dietary pat-

tern.

Being able to estimate dietary patterns at a small area

level using a classification such as OAC, allows for smarter tar-

geting of public health interventions, to improve diet and subse-

quent health. For example, to provide a specific intervention to in-

dividuals to living in ‘Constrained by Circumstances’Supergroup

(who consume the highest percentage of “Monotonous Low

Quantity Omnivore” diets) which would encourage them to in-

troduce more variety into their diets with the best addition being

fruit and vegetables. This could be done through social services

interventions in specific communities, or at a GP practice level

in local communities.

Further Work

Future studies could investigate how consuming each

of these dietary patterns could influence long term health, which

would strengthen the relevance of this research to public health

interventions. Another step would be to incorporate the cost of

these dietary patterns in order to assess the economic influence

of food price, compared to usage by geodemographic type. It

would be key to profile the dietary patterns of this cohort for

cities in the UK using a geodemographic classification and in-

vestigate patterns observed. Additional case studies from other

countries would allow for international comparisons to be made.

Conclusion

individuals reside. The type of area, using a small scale geo-

graphical unit, combined with demographic characteristics pro-

vides richer prediction of dietary consumption than the large

regional unit. Healthy or diverse dietary patterns are more com-

mon in geodemographic groups in the ‘Countryside’ or ‘Pros-

pering Suburbs’ with less healthy patterns in areas such as ‘Con-

strained by Circumstance’ and ‘Blue Collar Communities’. With

this in mind it may be beneficial to use such classifications in

the application of dietary advice to encourage healthy eating in

order to promote long term health. Geodemographic classifica-

tions are a useful tool to better understand spatial variations in

diet in the UK.

Data Sharing Statement

Further information on the UK Women’s Cohort Study Data is

available at www.ukwcs.leeds.ac.uk

Acknowledgements

The main author was funded through and ESRC/MRC PhD stu-

dentship. The UKWCS was initially established using funding

from the World Cancer Research Fund. Thanks to Dr. Lorna Fra-

ser for advice with the regression analysis.

CONFLICTS OF INTEREST: None.

Consent Statement

The study in the article has 35,000 participants who consented at

the time of recruitment to the cohort in the 1990s, as described

in the methods. In line with this consent, no personally identified

information is included in this article.

References

  1. DollRPetoR. The causes of cancer: quantitative estimates of avoidable risks of cancer in the United States today. J Natl Cancer Inst. 1981; 66: 1191-1308. doi: 10.1093/jnci/66.6.119210.1093/jnci/66.6.1192 https://doi.org/10.1093/jnci/66.6.1192
  2. KeyTAllenNSpencerETravisR. The effect of diet on risk of cancer. Lancet. 2002; 360: 861-868. doi: 10.1016/S0140- 6736(02)09958-010.1016/s0140-6736(02)09958-0 https://doi.org/10.1016/s0140-6736(02)09958-0
  3. The National Archives. Department of Health. Foresight-Tackling Obesities: Future Choices–Project report. Obesity: Healthy Weight, Healthy Lives. Web site. http://webarchive. nationalarchives.gov.uk/+/www.dh.gov.uk/en/Publichealth/ Healthimprovement/Obesity/DH_079713. Updated October 19, 2007. Accessed January 5, 2016