N09010: Do 'food deserts' exist? A multi-level, geographical analysis of the relationship between retail food access, socio-economic position and dietary intake

Study Duration: June 2000 to May 2002

Contractor: University of Newcastle upon Tyne

This project aims to determine the relationship between dietary intake and socio-economic factors at individual, household and neighbourhood levels, and retail access to a 'healthy' and affordable diet. Surveys of dietary intake and retail access to food will be undertaken and this data will be used to identify the extent to which dietary intake is associated with access and socio economic factors in Newcastle. These analyses will help determine whether 'food deserts' exist and, if so, to describe their characteristics. Where appropriate, recommendations for local and national government policy, health promotion practice and further research will be made.

The scientific objectives of this study are:

• To survey the dietary intake and socio economic circumstances of a cross sectional sample of the adult population in Newcastle.
• To identify and categorise retail food outlets in Newcastle by food availability and quality, relative price index and opening hours.
• To derive indicators and absolute access to retailed food using data collected on retail outlets.
• To undertake spatial analyses to show the geographical distribution of consumption of relatively "more", and "less healthy" diets and the distribution of purchasing patterns.
• To examine the relationship between indicators of dietary behaviour and indicators of relative retail food access and socio-economic position, using simple and multi-level regression and spatial analysis techniques.
• To interpret analyses and to produce a final report highlighting recommendations for local and national government policy, health promotion practice and further research.

The first phase of the project will consist of piloting the sampling, household and individual survey methods. The second phase will be a survey of population (representative sample of residents aged over 16 years in Newcastle) socio-economic characteristics and dietary patterns (via food frequency questionnaire). The third phase will consist of a survey of food availability, access and cost. Phase four will be the analysis of the data and development of dietary quality indices, development of food access indices, spatial analysis of dietary patterns and food access, and exploration of the relationship between access patterns and dietary intake. The final phase will be the interpretation and recommendations for policy, practice and future research.

We collected data on 5044 individuals living in 3153 households across the whole of Newcastle upon Tyne. The sample was broadly representative of the adult population of the city. We also collected data from 560 retail outlets selling food.

We found that 77% of households did their main food shopping at a large supermarket, such as Tesco or Safeway, although 14% used a smaller 'discount' supermarket, such as Netto or Kwiksave. 64% of households travelled to their main food shop by car, 16% went there on foot, 14% used public transport and 5% a taxi. Poorer households were more likely to shop locally or at a discount supermarket. 18% of householders reported difficulty carrying their shopping home, and this was 10 times more common among the poorest than the better off households. Households spent an average of £26 per person per week on food, though poorer and single parent households spent on average £22.

Being poor was associated with eating a higher fat diet, but drinking less alcohol. Higher intakes of fruit and vegetables were reported by those spending more on food, by women, by ethnic minorities and by older age groups. One of the strongest predictors of a healthy diet was awareness of current 'healthy eating' recommendations.

We found 216 small 'convenience' stores in Newcastle, as well as 20 large supermarkets, 18 discount supermarkets and 2 department stores retailing food. We also surveyed 47 greengrocers and 259 other outlets that sold at least one food item. General stores, supermarkets and delicatessens tended to be in more affluent areas and greengrocers, freezer centres and ethnic food stores in more deprived areas. In 24 out of 26 wards, there was at least one shop selling 27 or more of the 33 food items on our list, including most of the 'healthier' and 'less healthy' pre-packed items and all of the fresh fruit and vegetables.

Few shops (22 out of 560 or 4%) sold all 33 foods surveyed. Those that did were primarily multiple and discount supermarkets. The full range of 'less healthy' items was more available (in 50% of shops) than the full range of 'healthier' items (available in 25% of shops). Convenience stores were more likely to sell the full range of 'unhealthy' items than 'healthy' items. Larger stores (as measured by number of checkouts) sold more of the 33 items than smaller ones. Larger stores were also more likely to sell a full range of fresh fruit and vegetables and the 10 'less healthy' pre-packed items.

Our basket of 33 items cost £19.06 on average, though in the cheapest shop it was £14.44 and in the most expensive it was £23.57. Fruit and vegetables were significantly more expensive in the more affluent areas. However, overall only the number of checkouts in a retail outlet independently predicted cost-prices were generally cheaper in the larger stores. Discount and multiple supermarkets were cheapest for the pre-packed items. Fresh fruit and vegetables were cheapest in the market stalls and greengrocers. Overall, convenience stores and department stores were the most expensive shops, although only 3 out of 216 convenience stores sold all 33 items.

Overall, 91% of available fresh fruit and vegetable items were of reasonable quality. Quality was better at larger stores and in those selling a greater variety of produce. Good quality fresh produce was consistently available only at multiple supermarkets and department stores.

A shop selling any five of the 33 surveyed food items was within easy walking distance (250m) of almost all residential streets in the city. However, some parts of the city were further than 1km from a shop selling 10 'less healthy' food items or 10 fresh fruit and vegetables. The proportion of areas served by shops selling all 10 fruit and vegetables of good quality and at less than half of the average price was relatively small, although the best coverage was in the less affluent areas. People who shop at local and convenience stores, and to a lesser extent discount supermarkets, appear to be the most disadvantaged with respect to availability of food items.

Despite these differences in geographical access, our statistical analyses failed to show that price and availability in shops play a significant role in predicting the healthiness of consumers' diets overall. However, the vast majority of households did their food shopping at a large supermarket and travel there by car, an average of 1.9km (about 1 mile) from their home. Those using public transport or taxis travelled 1.5-2.4km. Together, these households account for 83% of the sample. Thus, most people travel outside their immediate locality to do their food shopping. This leaves those who do their shopping on foot - 490 households in our sample or 16% of the total. It is only for this group that local retail provision may be an important determinant of diet. When we looked at the diets of this group of individuals who do their shopping on foot, we found that they did have a relatively poor diet, including low fruit and vegetable consumption. As with car users, among walkers the main determinants of a healthy diet were dietary knowledge, age, lifestyle behaviours and socio-economic factors. However, availability of fruit and vegetables and distance to the main food shop also predicted healthiness of diet, suggesting that those able to, or prepared to, walk further to shops selling a wider range of produce may eat more healthily.

What it means and why it's important

This is the first study to have collected data at the same time on retail, socio-economic and dietary factors and analysed them together. However, the study has some limitations. For example, the study was undertaken in one city in the UK and so may not be representative of all areas. The sampling also led to some under-representation of poorer people, men and younger age groups.

Nevertheless, we have demonstrated marked differences in diets both socio-economically and geographically and, although these are not always in the anticipated direction, generally less healthy diets were associated with living in deprived areas and being poorer. However, overall we were unable to demonstrate an independent relationship between healthy eating and factors relating to local retailing. Our analysis suggests that the strongest predictors of 'less healthy'eating are dietary knowledge, demographic factors (e.g. age, sex, ethnicity, the presence of children within the household) and health-related behaviours (e.g. levels of physical activity and alcohol consumption). It therefore seems likely that the explanation for the wide variations in dietary intake seen across the whole population lie predominantly outwith the retail domain.

In answer to the question, 'do food deserts exist?' the answer must be 'only for some'. And that 'some' is a minority of people who, for a variety of reasons, do not or cannot shop outside their immediate locality, and for whom this locality suffers from poor retail provision of foods that make up a 'healthy' diet. Our finding that the key predictors of healthy eating overall are dietary knowledge and a healthier lifestyle, must lead us to question whether those people whose diet is 'less healthy' than desirable would eat more healthily if supplied with improved retail provision. Our study does not provide evidence to support retail provision as a primary cause of consuming an 'unhealthy' diet, although poor retail provision may be an important contributing factor in some, well defined, circumstances (e.g. when individuals are dependent on local retail provision and that provision is less than ideal). Approaches to tackling the problem of food poverty need to address poor knowledge and skills related to the acquisition and preparation of a 'healthy' diet, as well as the question of retail access at a local level for those without access to a car.

Final report is available from the FSA Library and Information centre.
To obtain a copy, please contact the Enquiry Desk, Dr Elsie Widdowson Library and Information Services, Food Standards Agency (Tel: 020 7276 8181/8182 or by e-mail to: InfoCentre@foodstandards.gsi.gov.uk ).

Presentations:

White M, Bunting J, Raybould S, Adamson A, Williams L, Mathers J. Do food deserts exist? Presentation to the North East Regional Community Food Network, October 2003.

White M, Bunting J, Raybould S, Adamson A, Williams L, Mathers J. Do food deserts exist? Paper presented at the International Food Poverty conference, Lisbon, July 2003.

White M, Bunting J, Raybould S, Adamson A, Williams L, Mathers J. Do food deserts exist? Invite lecture at the FSA Food Choice and Acceptability Programme Workshop. London, January 2003.

White M. Do food deserts exist? Invited seminar, Department of Social Medicine, University of Bristol, October 2002.

White M, Bunting J. Do food deserts exist? Invited seminar at the Social and Public Health Research Unit, University of Glasgow, May 2001.

Papers in preparation

A number of papers arising from the work are planned, the titles and content of which will be confirmed in due course.

Contact: Email: science@foodstandards.gsi.gov.uk