The major health problems of obesity, diabetes, CVD and cancer have all been related to diet (e.g. WHO, 1990; Block et al, 1992; Department of Health, 1998; Hooper et al 2001). In response to this, key public health campaigns have encouraged people to increase their daily consumption of fruit and vegetables, reduce their intake of salt and saturated fats, and eat more complex carbohydrates, amongst other aspects of diet. In light of these health messages, research based on cross-sectional and longitudinal research data sources suggest, for example, that there have been population level increases in consumption of fruits and vegetables, dietary fibre and poultry, and a decline in consumption of whole milk, butter and red meat (Prynne, Wagemakers, Stephen and Wadsworth, 2009; The Information Centre for Health and Social Care, 2009; Prynne, Paul, Mishra, Greenberg and Wadsworth, 2005) and eating less saturated fat, less trans fatty acids and less added sugar (Bates, Lennox and Swan, 2010).

The Department of Health has tasked NatCen to undertake scoping analysis project (including descriptive data analysis) to identify the type of food related data available from longitudinal sources in order to guide future research and policy priorities. The focus of this project is on longitudinal data in order to explore changes overtime and the factors associated with a change in diet. This will include analysis of the data by key break variables (to include sex, age, whether a family with children aged under 16, socio-economic classification, education/ highest qualification of mother (for datasets including children) and ethnic group (where data includes sufficient numbers)) and key health variables.

In addition, NatCen will be reporting to the Department of Health on the types of food related data currently being collected and suggesting where new data sources need to be developed including advice about questions/modules for inclusion on future surveys going forward.

Main research objectives

What can longitudinal surveys tell us about changes in eating and cooking practices?

The project will use different variables relating to eating and cooking practices to identify healthy and unhealthy practices, and explore how these vary by key sociodemographic variables and change over time. The primary sources for such data are ALSPAC and Whitehall II. These variables will include the types of fats used with vegetables and bread, and for frying and baking, the use of salt in cooking and at the table, frequency of eating takeaways, microwave and convenience meals and whether family meals are shared.

What can longitudinal surveys tell us about changes in choice and access to food?

Here key data relates to the ability to afford quality and variety of food. Primarily using data from the Family and Children's Survey (FACS) we will analyse a number of variables relating to choice and access, including whether the family is able to afford a cooked meal everyday, good quality/brand name food, fresh fruit and fresh vegetables daily and whether child maintenance goes on food. We will then be able to examine the circumstances of those of those with good choice and access to those with worse choice and access.

What can longitudinal surveys tell us about intake of key nutrients and foods?

The Department of Health has identified key nutrients and foods of policy interest for this project. Exact methods of analysis will vary depending on the data collection method used in the datasets accessed. Where possible, we will use will use the UK Dietary Reference Values as our benchmark and focus on recommended intakes for non-starch polysaccharide and percentage of energy from fat, saturated fat and non-milk extrinsic sugars. We may also include intake of Vitamin C, calcium and iron. For foods we will focus on intake of fruit and vegetables and, where age appropriate, relate this to the 5-a-day recommendation. For those surveys that primarily use food frequency questionnaires (such as Whitehall II) it may also be possible to develop a total fat score (classifying respondents as high, medium and low, an approach used in the Health Survey for England 2007).

References

Bates,Lennoxand Swan (2010). National Diet and Nutrition Survey: headline results from year 1 (2008/2009). Food Standards Agency and the Department of Health.

Block, Patterson & Subar (1992). Fruit, vegetables and cancer prevention: a review of epidemiological evidence. Nutr Cancer, 18: 1-20.

Department of Health (1994) Nutritional Aspects of Cardiovascular Disease.London: HMSO

Department of Health (1998) Nutritional Aspects of the Development of Cancer.London: The Stationery Office.

Hooper, Summerbell, Higgins et al (2001). Dietary fat intake and the prevention of cardiovascular disease: a systematic review. BMJ, 322: 757-763.

Prynne, Wagemakers, Stephen andWadsworth(2009). Meat consumption after disaggregation of meat dishes in a cohort of British adults in 1989 and 1999 in relation to diet quality. Euro Journ of Clin Nutr, 63: 660-666.

The Information Centre for Health and Social Care (2008). Health Survey for England 2007- Healthy lifestyles: knowledge, attitudes and behaviours.

The Information Centre for Health and Social Care (2009). Health Survey for England- 2008 trend tables http://www.ic.nhs.uk/statistics-and-data-collections/health-and-lifestyl...

World Health Organisation (1990).Diet, nutrition, and the prevention of chronic diseases. Report of a WHO Study Group.Geneva: World Health Organisation

Other data sets to be included in this project-

Freely available datasets

? English Longitudinal Study of Aging (ELSA) (http://www.esds.ac.uk/longitudinal/access/elsa/l5050.asp )

? Families and Children Study (FACS) (http://www.esds.ac.uk/findingData/snDescription.asp?sn=4427)

? British Household Panel Survey (BHPS) http://www.esds.ac.uk/longitudinal/access/bhps/L33196.asp - Youth Cohort

Datasets subject to access application

? Whitehall II

http://www.ucl.ac.uk/whitehallII/

? MRC National Study of Health and Development

http://www.nshd.mrc.ac.uk/