The first report of the National Diet and Nutrition Survey (NDNS) Rolling Programme was published in February 2010. The full report is available here
The NDNS Rolling Programme is a continuous cross-sectional survey (i.e. a sample of people within a population) of the food consumption, nutrient intakes and nutritional status of people aged 18 months and older living in the UK.
The survey is carried out on behalf of the Food Standards Agency and the Department of Health by a consortium of three organisations: the Health Group at the National Centre for Social Research, Medical Research Council Human Nutrition Research, and the Department of Epidemiology and Public Health at the Royal Free and University College London Medical School.
The Food Standards Agency and the Department of Health primarily use the data to develop, implement and monitor policies to improve the nation’s diet and nutritional status (e.g. the Saturated Fat and Energy Intake Programme), and to support risk assessments for food chemicals to protect consumer safety. The data are also used extensively by researchers, other Government departments, the food industry, health professionals and others to inform their work.
The Year 1 data were collected between February 2008 and June 2009. To obtain a representative sample of the UK population, households were selected randomly from 130 geographical areas across England, Wales, Scotland and Northern Ireland. One adult and a child, or a child only, were selected at random from each household and invited to take part.
The first stage of the survey comprised a face-to-face interview with each participant, completion of a 4-day food diary and measurements of height and weight. A variety of other information was collected too, including information on shopping and food preparation practices, cooking skills, housing tenure and employment. People that completed the first stage were invited to give physical activity measures, a blood sample, and a 24-hour urine sample.
The survey methodology being used for the NDNS Rolling Programme is different to that used in previous NDNS surveys. Differences in survey methodology include:
- Data is collected each year for all age groups, hence ‘rolling programme’. Whereas in the past data was collected at one point in time for a particular age group, and done so at irregular intervals.
- A 4-day estimated (un-weighed) food diary is now used in place of a 7-day weighed food diary, primarily to make the process easier for participants.
- Composite dishes (i.e. dishes with multiple food components, such as lasagne) are disaggregated into their separate ingredients to give a more accurate estimate of actual food types consumed (e.g. for meat, vegetables etc).
Findings from Year 1
The Year 1 report presents results for a UK representative sample of 1000 people aged 1.5 to 64 years – approximately 500 adults and 500 children. Because of the small sample size, results for older people (aged 65 years and over) have not been included. Also, the authors recommend that small changes be interpreted with caution as they may have occurred at random. In addition, a potential limitation of the Year 1 data is that the 4 days on which the food diaries were kept by participants included both Saturday and Sunday, and it is likely that the day of the week influences some people’s food choices.
The key findings of the survey as summarised by the Food Standards Agency are:
- People are eating less saturated fat, trans fat and added sugar than they were 10 years ago, when the survey was last carried out.
- Saturated fat intakes in adults have dropped slightly to 12.8% of food energy, but are still above the recommended level of 11%. Whereas, the population’s trans fat intakes, having also fallen slightly, are well within recommended levels.
- People are still eating too much added sugar, currently 12.5% of food energy intake compared to the recommended 11%.
- A third of men and women are now eating the recommended 5-A-DAY fruit and vegetables.
- People are still not eating enough fibre, which is essential for healthy digestion. On average, intakes are 14g per day for adults, some way below the recommended 18g.
- Consumption of oily fish, which is the main source of omega 3 fatty acids in the diet, remains below the recommended one portion per week.
- Iron intakes among teenage girls and women are still low, which can lead to iron deficiency and anaemia. However, overall, vitamin and mineral intakes among the population are slightly improved.
It is anticipated that results from Year 2 (2009/10) of the NDNS Rolling Programme will be published in early 2011. With data collected each year, the larger sample size will allow statistical analysis of the observed differences in food consumption and nutrient intakes to be undertaken. In addition, as more blood and urine samples are collected from participants, this will allow the authors to report on the measures of nutritional status for micronutrients that are of particular interest to public health, such as sodium, iron and riboflavin.