Abstract
Objective
To describe the diet costs of adults in the National Diet and Nutrition Study (NDNS) and explore patterns in costs according to sociodemographic indicators.
Design
Cross-sectional diet diary information was matched to a database of food prices to assign a cost to each food or non-alcoholic beverage consumed. Daily diet costs were calculated, as well as costs per 10 MJ to improve comparability across differing energy requirements. Costs were compared between categories of sociodemographic variables and health behaviours. Multivariable regression assessed the effects of each variable on diet costs after adjustment.
Setting
The NDNS is a rolling dietary survey, recruiting a representative UK sample each year. The study features data from 2008–2010.
Subjects
Adults aged 19 years or over were included. The sample consisted of 1014 participants.
Results
The geometric mean daily diet cost was £2·89 (95 % CI £2·81, £2·96). Energy intake and daily diet cost were strongly associated. The mean energy-adjusted cost was £4·09 (95 % CI £4·01, £4·18) per 10 MJ. Energy-adjusted costs differed significantly between many subgroups, including by sex and household income. Multivariable regression found significant effects of sex, qualifications and occupation (costs per 10 MJ only), as well as equivalized household income, BMI and fruit and vegetable consumption on diet costs.
Conclusions
This is the first time that monetary costs have been applied to the diets of NDNS adults. The findings suggest that certain subgroups in the UK – for example those on lower incomes – consume diets of lower monetary value. Observed differences were mostly in the directions anticipated.
To describe the diet costs of adults in the National Diet and Nutrition Study (NDNS) and explore patterns in costs according to sociodemographic indicators.
Design
Cross-sectional diet diary information was matched to a database of food prices to assign a cost to each food or non-alcoholic beverage consumed. Daily diet costs were calculated, as well as costs per 10 MJ to improve comparability across differing energy requirements. Costs were compared between categories of sociodemographic variables and health behaviours. Multivariable regression assessed the effects of each variable on diet costs after adjustment.
Setting
The NDNS is a rolling dietary survey, recruiting a representative UK sample each year. The study features data from 2008–2010.
Subjects
Adults aged 19 years or over were included. The sample consisted of 1014 participants.
Results
The geometric mean daily diet cost was £2·89 (95 % CI £2·81, £2·96). Energy intake and daily diet cost were strongly associated. The mean energy-adjusted cost was £4·09 (95 % CI £4·01, £4·18) per 10 MJ. Energy-adjusted costs differed significantly between many subgroups, including by sex and household income. Multivariable regression found significant effects of sex, qualifications and occupation (costs per 10 MJ only), as well as equivalized household income, BMI and fruit and vegetable consumption on diet costs.
Conclusions
This is the first time that monetary costs have been applied to the diets of NDNS adults. The findings suggest that certain subgroups in the UK – for example those on lower incomes – consume diets of lower monetary value. Observed differences were mostly in the directions anticipated.
| Original language | English |
|---|---|
| Pages (from-to) | 151-159 |
| Journal | Public Health Nutrition |
| Volume | 18 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2015 |
Bibliographical note
Sources of funding: K.A.T. is funded by an Economic and Social Research Council/Medical Research Council (ESRC/MRC) PhD studentship. ESRC and MRC had no role in the design, analysis or writing of this article. The original data creators, depositors or copyright holders of the NDNS and the UK Data Archive bear no responsibility for their further analysis or interpretation.NDNS copyright: Crown copyright is held jointly with the National Centre for Social Research. Crown copyright material is reproduced with the permission of the Controller of HMSO and the Queen's Printer for Scotland.
Conflicts of interest: There are no conflicts of interest to declare.
Ethical approval: This study contains secondary analyses of the NDNS. The NDNS obtained ethical approval from the Oxfordshire A Research Ethics Committee. Further details of ethical approval are described in the survey report( Reference Bates, Lennox and Bates 19 ).
Authors’ contributions: K.A.T. carried out the analysis and wrote the first draft of this paper. J.E.C. and C.H. provided guidance through PhD supervision, as well as comments and edits on the paper drafts.
Acknowledgements: The authors would like to acknowledge Kevin Tarbutt (funded by a Rank Prize Fund) and Edmund Parks, who created and updated the DANTE cost database, as well as the original NDNS data creators, depositors and funders: the National Centre for Social Research, the Northern Ireland Statistics and Research Agency, the Medical Research Council, University College London Medical School, the Food Standards Agency, the Department of Health and the UK Data Archive.