Dr Alison StephenPopulation Nutrition ResearchMRC Human Nutrition ResearchCambridge, UK
NATIONAL DIET AND NUTRITION SURVEY ROLLING PROGRAMME
Report of the Comparison Study
NDNS - Background
Previous NDNS surveys:
Children aged 1.5 - 4.5 y - fieldwork 1992-3
OPCS, DNU. Dental: Birmingham, Newcastle
People aged 65 + y - fieldwork 1994-5
SCPR, DNU. Dental: UCL
Young people aged 4-18 years - fieldwork 1997
ONS, HNR. Dental: Birmingham, Newcastle
Adults aged 19-64 years - fieldwork 2000-1
ONS, HNR.
NDNS - Review
Following review of dietary survey programme in
2002/03, FSA Board agreed to rolling programme model
for future NDNS.
Survey will run continuously with fieldwork carried out
every year
Generate data more rapidly
Track changes over time more easily
Collect additional data at short notice
More responsive to policy needs
NDNS Consortium NatCenNatCen
NDNS office - London
Operations – Brentwood
NISRA
Interviewers & Nurses
HNRHNR
NDNS office
Field lab coordination
Bioanalysis/NBL
DLW
Dietary Assessment
Sun exposure
Data Management
UCLUCLSurvey DoctorPhysical Activity
Service AgreementsService AgreementsAddenbrookesAberystwyth UniversityField Laboratories
Responsibilities – Nat Cen
General management issues
Sampling
Fieldwork
Interviews – self complete, CAPI
Dietary assessment
Physical measurement protocols & equipment (H & W, WH, MUAC,
demi-span, infant length, BP)
Physical activity - Questionnaires, Actigraph
Blood and urine collections
Administration of DLW
Briefings
Liaison with NISRA
Reports - Monthly reports to FSA, response rate, main reports
Responsibilities - HNRDietary assessment
Diet coding and editing – queries, new foods etc
Nutrient databank
Dietary data entry and analysis computer system
Dietary feedback forms for respondents
Blood and urine analysis
Recruitment of local processing labs, training
Ethics arrangements for processing laboratories
Supplies for collection and all analyses
Analysis of blood and 24h urine samples
Storage of unused blood for 10 years
Doubly labelled water
Production of samples for field
Receipt and analysis of urine
Data analysis and report writing: dietary data, blood and urine, DLW
Responsibilities – UCL
Survey doctor
Physical activity
Oral health questions
NDNS - managementProject Board
Chaired by FSA, with representatives from all 4 countries
Department of Health
External advisors: Sheila Bingham, Hilary Powers
Senior representatives of Nat Cen, HNR and UCL
Meets 4-6 times per year
NDNS Management Team
Chaired by Nat Cen
Representatives of Nat Cen, HNR and UCL – some invitees
depending on agenda items
Meet 2-3 times per year
HNR management team
Key members of HNR NDNS team – meets every 2-3 months
NDNS –main elements
Comparison Study
Jan 07– Feb 08 (fieldwork March – July 2007)
Sampling 1840 – final number 1049, 160 DLW, reasonably nationally
representative (no NI)
Run-in
Feb- March 2008
N = 5 points/month, 10 DLW, blood, urine
Main stage
April to March each year
10 points/month
Interview/Dietary assessment: Core (1000), Scot (boost to 400/y), NI
(boost to 200/y)
Blood: Core, Scot, NI
Urine: Core, Scot, NI
DLW: Core (160)
Aims of the Comparison Study
compare response rates for 4-day unweighed diary and 4
interviewer-administered 24 hour recalls
compare quality of data and degree of under-reporting achieved
test a new physical activity questionnaire
investigate feasibility of physical activity monitors for children
validate the new physical activity questionnaire against an
objective measure of energy expenditure
test questions on food consumption and social and domestic
circumstances affecting consumption
investigate feasibility of obtaining more detailed information on
food packaging
investigate feasibility of sun exposure questionnaire
Aims of the Comparison Study
compare response rates for 4-day unweighed diary and 4
interviewer-administered 24 hour recalls
compare quality of data and degree of under-reporting achieved
test a new physical activity questionnaire
investigate feasibility of physical activity monitors for children
validate the new physical activity questionnaire against an
objective measure of energy expenditure
test questions on food consumption and social and domestic
circumstances affecting consumption
investigate feasibility of obtaining more detailed information on
food packaging
NDNS Comparison StudyTable 4B Breakdown of CU-level response rates
Outcome 24-hour recall Diary All
N % N % N %
ISSUED ADDRESSES 920 920 1840
Ineligible 130 14 109 12 239 13
Eligible 790 86 811 88 1601 87
ELIGIBLE Cus
Total unproductive: 379 48 375 46 754 47
Non-contact 12 2 14 2 26 2
Refused 309 39 299 37 608 38
Other reason 58 7 62 8 120 7
Partially productive CUs(<3 dietary days for all respondents)
27 3 13 2 40 2
Fully productive CUs (3+ dietary days for at least one respondent)
384 49 423 52 807 50
NDNS Comparison StudySummary of interviewer and coder feedback
both dietary assessment methods presented some
challenges in the field for interviewers and respondents
one of the main determinants of the chosen method was
the need to include two weekend days in the dietary
assessment period, which was more difficult to achieve for
recall for both interviewers and respondents
0
2
4
6
8
10
12
4-6y 7-10y 11-14y 15-18y 19-34y 35-49y 50-64y 65+y 4-6y 7-10y 11-14y 15-18y 19-34y 35-49y 50-64y 65+y
En
erg
y m
J/d
24h recall males diary males
24h recall females diary females
NDNS Comparison study Energy intake by 24h recall and estimated diary
n 14,14 9,26 16,13 23,22 36,39 52,51 44,53 38,37 12,16 14,14 14,11, 13,20 44,51 63,81 60,60 52,55
0
2.5
5
7.5
10
12.5
15
4-10y 11-15y 16-49y 50-64y 65+y 4-10y 11-15y 16-49y 50-64y 65+
En
erg
y m
J/d
Intake recall Expenditure recall
Intake diary Expenditure diary
NDNS Comparison study Tables 7A and7B -Energy intake and expenditure (DLW) for recall and diary - Males
Each cell n =8
0
2.5
5
7.5
10
12.5
15
4-10y 11-15y 16-49y 50-64y 65+y 4-10y 11-15y 16-49y 50-64y 65+
En
erg
y m
J/d
Intake recall Expenditure recall
Intake diary Expenditure diary
NDNS Comparison study Tables 7A and7B - Energy intake and expenditure (DLW) for recall and diary - Females
Each cell n =8
0
2.5
5
7.5
10
12.5
15
4-10y 11-15y 16-49y 50-64y 65+y 4-10y 11-15y 16-49y 50-64y 65+E
ne
rgy
mJ
/d
Intake recall Expenditure recall
Intake diary Expenditure diary
NDNS Comparison study Tables 7A and7B - Energy intake and expenditure (DLW) for recall and diary
Each cell n =8
0
2.5
5
7.5
10
12.5
15
4-10y 11-15y 16-49y 50-64y 65+y 4-10y 11-15y 16-49y 50-64y 65+
En
erg
y m
J/d
Intake recall Expenditure recall
Intake diary Expenditure diary
Males Females
-100%
-75%
-50%
-25%
0%
25%
50%
75%
100%
4-10y 11-15y 16-49y 50-64y 65+y 4-10y 11-15y 16-49y 50-64y 65+
% u
nd
er,
ad
eq
ua
te a
nd
ov
er
rep
ort
ing
Under recall Adequate recall Over recall
Under diary Adequate diary Over diary
NDNS Comparison study Table 7D - % Under, adequate and over reporting - Males
Each cell n =8
-100%
-75%
-50%
-25%
0%
25%
50%
75%
100%
4-10y 11-15y 16-49y 50-64y 65+y 4-10y 11-15y 16-49y 50-64y 65+
% u
nd
er,
ad
eq
ua
te a
nd
ov
er
rep
ort
ing
Under recall Adequate recall Over recall
Under diary Adequate diary Over diary
NDNS Comparison study Table 7D - % Under, adequate and over reporting - Females
Each cell n =8
-100%
-75%
-50%
-25%
0%
25%
50%
75%
100%
4-10y 11-15y 16-49y 50-64y 65+y 4-10y 11-15y 16-49y 50-64y 65+
% u
nd
er,
ad
eq
ua
te a
nd
ov
er
rep
ort
ing
Under recall Adequate recall Over recall
Under diary Adequate diary Over diary
NDNS Comparison study Table 7D - % Under, adequate and over reporting -
Each cell n =8
-100%
-75%
-50%
-25%
0%
25%
50%
75%
100%
4-10y 11-15y 16-49y 50-64y 65+y 4-10y 11-15y 16-49y 50-64y 65+
% u
nd
er,
ad
eq
ua
te a
nd
ov
er
rep
ort
ing
Under recall Adequate recall Over recall
Under diary Adequate diary Over diary
Males Females
NDNS Comparison StudySummary of energy intake and misreporting
there were few differences in energy intake for the two methods.
Only in men aged 35-49 years was there a difference, with energy
intake for diary lower than for 24h recall
there were few differences in misreporting between methods.
Both methods had substantial under-reporting, but not in any
consistent direction
there appeared to be slightly more over-reporting with 24h recall
in young children than diary
24 h recall Diary Previous NDNS*
M F M F M F
n 62 53 75 61 856 845
Protein g 71.3 55.6 69.8 57.4 61.6 51.2
Fat g 74.6 59.9 71.4 65.7 74.7 63.1
Carbohydrate g 253 227 249 213 260 214
Total sugars g 116 106 113 95 117 97
NMES g 84 78 86 67 85 69
NSP g 12.2 10.7 11.7 10.6 11.2 9.7
Calcium mg 935 714 798 719 784 652
Iron mg 10.2 9.2 9.8 8.8 10.4 8.3
Folate µg 229 201 219 188 240 194
Vitamin C mg 97.5 96.5 86.6 75.9 75.2 71.2
NDNS Comparison study Nutrient intakes – young people 4-18 years
* 1997
24 h recall Diary Previous NDNS*
M F M F M F
n 132 167 143 192 833 891
Protein g 86.2 67.5 88.4 66.9 61.6 51.2
Fat g 86.2 64.0 83.1 63.8 86.5 61.4
Carbohydrate g 261 199 246 192 275 203
Total sugars g 115 90 102 83 118 88
NMES g 80 54 69 50 79 51
NSP g 14.6 13.1 14.3 12.6 11.2 9.7
Calcium mg 928 783 892 770 937 726
Iron mg 12.7 10.3 12.3 10.4 13.7 10.5
Folate µg 300 238 281 237 311 213
Vitamin C mg 85.2 93.2 84.9 84.4 66.5 62.0
NDNS Comparison study Nutrient intakes – adults 19-64 years * 2000/01
24 h recall Diary Previous NDNS
M F M F M F
n 38 52 37 55 632 643
Protein g 75.9 66.6 76.1 67.8 71.5 56.0
Fat g 80.5 62.5 71.1 61.5 74.7 58.0
Carbohydrate g 238 183 220 199 232 175
Total sugars g 114 85 100 94 103 79
NMES g 75 46 53 51 64 44
NSP g 14.1 12.8 15.6 14.3 13.5 11.0
Calcium mg 874 768 898 840 836 690
Iron mg 11.6 10.0 12.3 11.2 11.0 8.6
Folate µg 278 266 280 272 270 207
Vitamin C mg 88.4 95.0 99.5 88.0 66.9 60.7
NDNS Comparison study Nutrient intakes – older adults 65+ years
* 1994/5
24 h recall Diary Previous NDNS
M F M F M F
n 62 53 75 61 856 845
Protein % energy 15.0 13.8 15.1 14.3 12.9 12.9
Fat % energy 34.4 33.1 34.6 36.2 35.3 35.9
Carbohydrate % energy 50.1 53.1 49.7 49.4 51.2 50.7
Total sugars % energy 22.3 24.6 22.1 21.9 23.0 23.0
NMES % energy 15.7 17.8 16.6 15.3 16.7 16.4
NDNS Comparison study Nutrient intakes as % energy– young people 4-18 years
24 h recall Diary Previous NDNS
M F M F M F
n 132 167 143 192 833 891
Protein % energy 15.6 16.5 16.6 16.5 15.4 15.9
Fat % energy 33.9 33.9 34.3 34.3 33.5 33.5
Carbohydrate % energy 43.7 44.7 42.7 43.7 44.7 46.7
Total sugars % energy 19.1 19.9 17.4 18.6 19.1 20.2
NMES % energy 13.1 11.9 11.6 11.0 12.8 11.7
NDNS Comparison study Nutrient intakes as % energy – adults 19-64 years
24 h recall Diary Previous NDNS
M F M F M F
n 38 52 37 55 632 643
Protein % energy 14.9 17.4 16.5 17.2 15.4 16.3
Fat % energy 34.3 34.9 33.5 34.2 34.3 35.6
Carbohydrate % energy 43.4 44.2 44.0 46.2 46.4 46.9
Total sugars % energy 20.5 20.4 19.7 21.1 20.2 20.8
NMES % energy 13.2 10.9 10.1 11.0 12.6 11.3
NDNS Comparison study Nutrient intakes as % energy – adults 65+ years
NDNS Comparison StudySummary of nutrient intake
there were no substantial differences in nutrient intake by methodcarbohydrate
fat
protein
total sugars
non-milk extrinsic sugars (NMES)
non-starch polysaccharide (NSP)
calcium
iron
folate
vitamin C
results were similar to past NDNS surveys: older people (1994-95), young
people (1997) and adults (2000-01).
Respondents were offered feedback on
their diet & 84% did request feedback
Challenges
High throughput requires an
automated letter
Contents
Informative
Not too lengthy
Easy to understand
Limited by time available to
produce outputs
Feedback questionnaire to evaluate
the success of the dietary feedback
letters
Key Nutrients ReportedKey Nutrients Reported•Fat intake as % of total energy•Saturated fat intake as % total energy•NMES•Dietary fibre•Vitamin C•Folate•Calcium•Iron•Energy intake (Kcal/d)
NDNS Comparison study Dietary feedback
Fat intake is expressed as a % of total energy consumed. Some fat is essential in the diet but children and adults tend to eat too much in the UK.
To assist with the maintenance of a healthy body weight and reduce the risk of chronic diseases such as heart disease, UK guidelines state that fat should only make up 33% or less of total energy.
UK intake range
25 30 35 40 45Fat as % total energy
Your Child's Intake: 40.0 %UK Guideline: 33.0 %
NDNS Comparison study Dietary feedback
Generating Dietary Feedback LettersGenerating Dietary Feedback Letters
Recalls/Diariesediting & coding “complete”
Emily & Rachel:New food nutrient
composition data entry
Darren:input info on feedback
requested & respondent identifiers
Data output
Data checking
Individual feedback letters
Graphs
Feedback Checking
Feedback letter transfer to NatCen
Darren
Darren/Gemma
Celia
Adrian/Mark/Gemma
Birgit
Zoe
NDNS Comparison Study 2007 NDNS Comparison Study 2007 NDNS Comparison Study 2007 NDNS Comparison Study 2007
Question Yes % No % Not answ %
1. Do you think that the graphs showing your results compared with UK
guidelines for the population are easy to understand?
97 3 0
2. Do you think comparing your results with UK guidelines is useful? 98 2 0
3. Is there any other information about your diet you would like to receive? 26 68 6
5. Would you be interested in a web page for NDNS participants that lists more
information about the survey (for example results as they emerge), updates on
what the nation consumes and nutrition information and advice?
42 56 2
A % B % Not answ %
4. Some additional information we could provide would take longer to produce
e.g. No. of portions of fruit and vegetable you consume.
A) I would like to receive more information about my diet even if I have to wait
up to 12 months to receive it.
B) B) I am happy with the information provided which I receive within 3
months after completion of the dietary assessment.
32 64 4
Table 5B Response to feedback questionnaire
Feedback questionnaire: some respondent comments
“I am concerned at the unrealistic accuracy implied by some of your
analysis, eg my folate intake was reported as 381µg/d. Can you really
make assessments to 3 figures on the basis of a few days data – NO!!”
“I cannot see how this survey is of any use and seems to me to be rather a
waste of time and money especially after the depth of detail concerning
diet that is needed.”
“I am over 80 years of age, can’t I have more information in less than 12
months?”
“I was very impressed with the information returned and am very
appreciative of the extra time put in to produce this feedback. Thanks.”
Contributors to writing the Comparison Study report
HNR
Alison Stephen
Birgit Teucher
Les Bluck
Darren Cole
Emily Fitt
Adrian Mander
Rachel Woodward
Anthony Wright
Nat Cen
• Beverley Bates
• Caireen Roberts
• Helen Mackenzie
• Claire Deverill
UCL
• Jenny Mindell