National Diet and Nutrition Survey (NDNS) rolling programme

1. National Diet and Nutrition Survey (NDNS) rolling programme Gillian Swan Nutrition Division Food Standards Agency

2. Food Standards Agency Aims include: • To make it easier for all consumers to choose a healthy diet and so improve quality of life by reducing diet-related disease • To continue to reduce food-borne illness and the risks to consumers from chemical contamination of food throughout the UK.

3. National Diet and Nutrition Survey programme (NDNS) • Major component of Agency’s dietary survey programme. • In its previous form - a series of cross-sectional surveys of different age groups • Now setting up a rolling programme to collect data continuously

4. NDNS programme as it was • Series of cross-sectional surveys of diet and nutritional status covering discrete population age groups • Dietary assessment - weighed record for four or seven days • Blood and urine sample • Contextual information – physical measurements, physical activity, lifestyle characteristics

5. National Diet and Nutrition Survey Programme

6. Features of the NDNS • Cross-sectional • Data collected on individuals • Detailed food consumption data • Linked data on food, nutrient intake, nutritional status and contextual information in individuals

7. Need for NDNS data • Underpins Agency’s work to protect consumer safety & promote healthy diets. • Detailed food consumption data essential for assessing exposure to food chemicals • Assess nutritional issues in the population and identify where action needed • Means of measuring progress towards Government targets and objectives

8. Why change the approach? • Concerns about current programme • Lack of timeliness - 15 year gap between surveys • Lack of flexibility • Declining response rates • Data quality (under-reporting) • Agreement from Agency’s Board to move to rolling programme

9. Features of rolling programme • Survey runs continuously - fieldwork every year • Data points generated more frequently - better tracking of trends over time • Greater flexibility to collect additional data or boost sample for specific groups

10. Features of rolling programme • Core programme - 1000 people per year (adults and children) • All ages from 1½ years upwards • Designed to be representative of the UK population • Excludes infants, pregnant women, people in institutions

11. Rolling programme – components (1) • Face to face interview • Dietary assessment • Physical measurements • height • weight • waist and hip circumference • mid-upper arm circumference (children) • Blood pressure

12. Rolling programme - components (2) • Blood sample analysed for range of nutritional status indices • 24-hour urine collection (salt intake) • Physical activity questionnaire

13. Dietary assessment • Require detailed quantitative data on food consumed by each respondent • Weighed record used for previous NDNS - but high respondent burden • Response rates declining • Concern about under-reporting

14. Choice of Dietary Assessment Method • Pilot work to compare two methods • Multiple pass 24 hour recall • 4 non-consecutive days • Unweighed diary • 4 consecutive days • Compare response rates and data quality to decide on best method

15. NDNS rolling programme timetable • Comparison study to choose dietary assessment method – spring 2007 • Dress rehearsal - early 2008 • Rolling programme fieldwork commences April 2008 • Results for first year 2008/09 available end of 2009

16. Reports and Datasets • Key results published on FSA website annually (www.food.gov.uk) • Datasets sent to the Data Archive annually • Printed report with commentary to cover first four years results

17. How can the data be used? • Monitor trends & progress towards targets • Compare intakes with recommendations • Describe characteristics of people with low (or high) intakes/status • Modelling changes in diet or composition • Other uses ……..