The National Food Survey (NFS) was originally set up in 1940 to monitor the adequacy of the diet of urban working class households. It evolved into a continuous sampling enquiry into the domestic food consumption and expenditure of all private households, regardless of class. This open data release covers the years from 1974 to 2000, when the National Food Survey and Family Expenditure Surveys were merged into the Expenditure and Food Survey, and then became known as the Family Food Module of the Living Costs and Food Survey.
The data that Defra is releasing now as Open Data are the only remaining data in electronic form. They were stored in Microsoft Access database format as five-year databases except for the last year, 2000. For each year there was a standard set of data tables:
- Diary data (the summarised records of each purchase of food for consumption in the home, taken from the National Food Survey log-books)
- Household data (the characteristics of the household such as location, occupation of Head of Household and Housewife (if present) etc., taken from the interviewer’s questionnaire)
- Mealsout data (record of all meals taken outside the home, taken from the log-books)
- Visitor data (record of all visitors to the home, taken from the questionnaire)
- Person data (record of each member of the household such as age, gender, occupation, taken from the questionnaire)
Some changes have been made to make these suitable for release as Open Data. These are detailed in the document “Introduction to the National Food Survey” within the data release. In particular, the Person data has been withheld from open release for disclosure control purposes. All other data is available as separate tables in tab-separated-value text format for individual years.
In addition, there are
- Nutrient Conversion Factor tables for each year (details in the other documentation)
- lookup tables to translate the short field codes in the original data tables into longer, more meaningful terms, taken from the database system.
- some additional tables and documentation to try to clarify meanings and changes in the usage of data fields, and some of the changes made to the data for disclosure control purposes. More details are in the “Introduction” file.
Trying to find a balance between providing a rich and useful source of food purchasing data, and protecting the privacy of respondents throughout the years, has been one of the biggest challenges involved in releasing this data. We have consulted extensively with privacy experts, data protection specialists in Defra and a group of trusted external data testers in the run up to releasing this data. We have published a privacy impact assessment (see link above) which takes you through our process creating a data set which minimises privacy risks while hopefully still being useful to the public.
The data is being released under the Open Government Licence v3.0 (OGL). For the avoidance of doubt, attempts to re-identify individuals from the openly licensed datasets is not an acceptable use of the data. Any instances of this brought to Defra’s attention will be directed to the Information Commissioner’s Office for investigation.
Defra takes the privacy of respondents to Family Food surveys seriously. If you identify a privacy-related risk please let us know via email@example.com. Defra will remove the data from data.gov.uk and other online locations if a serious privacy breach is identified, and work to resolve it.
The open data release can be found by clicking here.
Another version of this data, without the disclosure control changes, is available from the United Kingdom Data Service under an End User Licence. For details go to the UK Data Service and search for National Food Survey.
Some annual reports and datasets from the National Food Survey are available online at this link
You may find the National Food Survey/Family Food timeline helpful in understanding the evolution of the food surveys.