Submitting InstitutionUniversity of Ulster
Unit of AssessmentAllied Health Professions, Dentistry, Nursing and Pharmacy
Summary Impact TypeHealth
Research Subject Area(s)
Medical and Health Sciences: Nutrition and Dietetics, Public Health and Health Services
Summary of the impact
Changing global patterns of agricultural production, food availability
and processing are having profound impacts on individual food consumption
and population health. Thus accurate data on individual food consumption
are fundamental for effective planning of agricultural investments and for
the implementation of sound public health nutrition policy. Research
undertaken at the University of Ulster has demonstrated that mis-reporting
in dietary surveys is pervasive and consequently is obscuring diet-health
associations. This research has prompted a major paradigm shift in the way
public health policy makers interpret dietary intake data.
The ability to accurately measure food, and thus, nutrient intake, is of
fundamental importance. For example, food regulatory authorities and
agencies require valid intake data for a variety of policy making and
research purposes in the areas of nutrition monitoring and surveillance,
dietary guidance, food fortification, environmental exposure assessment,
and nutrition assistance and education program planning and evaluation.
However, until relatively recently, no biomarkers were available for
independently evaluating the validity of dietary assessments.
Consequently, up until 1990 there existed a large body of literature
spanning five decades which, in drawing conclusions about the
relationships between diet and health made the tacit assumption that the
usual methods of dietary assessment provided valid measures of habitual
dietary intake. The possibility that human subjects may, consciously or
sub-consciously, mis-report their food intakes was not widely
contemplated. The advent of the doubly labelled water (DLW) method for
providing robust and accurate measurements of energy expenditure offered
the first opportunity to objectively assess the validity of reported
energy intakes in free-living, weight-stable human subjects.
In collaboration with the MRC Dunn Nutrition Laboratory, Cambridge, two
validation studies were carried outat the University of Ulster.. In the
first study of a randomly selected sample of free-living men and women,
mean energy intake by weighed dietary records was 82% and 81% of energy
expenditure respectively, indicating substantial bias to the
under-estimation of habitual food intake (Livingstone et al,
1990). If these results were assumed to be representative of all randomly
selected population samples, then the implications for all dietary
surveys, and particularly large epidemiological surveys, were enormous. In
the second validation study in 78 young people mis-reporting was shown to
increase with increasing age and, moreover, was not specific to any one
dietary intake methodology (Livingstone et al, 1992).
Initially there was enormous reluctance by the nutrition community to
accept the possibility of such bias in dietary surveys. The results of the
DLW studies were viewed as based on a new and untried technique in a small
and highly selected sample of subjects. This led Black et al
(1991) to review published national dietary surveys in the UK, elsewhere
in Europe and the US and to demonstrate conclusively that under-reporting
of energy intake was both serious and widespread.
Subsequently in 2001, Barbara Livingstone was invited by the
International Life Sciences Institute (North America) to write a
systematic review of the current status of knowledge with regard to
markers of the validity of reported energy intake (one of a series of
reviews evaluating the science of biomarkers of exposure in nutritional
epidemiology) (Livingstone & Black, 2003). This paper provided the
first comprehensive review of 43 DLW validation studies and confirmed the
serious under-estimation of energy intakes (-20% on average). This seminal
review, published in the Journal of Nutrition has since been highly cited
by researchers worldwide.
Key Researchers at Ulster:
Current key staff: Dr MBE Livingstone (Lecturer/Senior Lecturer in
External academic collaborators (1987 - 2003):
Dr AM Prentice (Senior Scientist)
Dr WA Coward (Senior Scientist)
Dr AE Black, (Chief Research Officer)
MRC Dunn Nutrition Unit, Cambridge, CB4 1XJ
References to the research
The work has been published in top nutrition and medical journals
and was undertaken in collaboration with researchers at MRC Dunn
Livingstone, M. B. E., Robson, P. J., Wallace, J. M. W. (2004). Issues in
dietary intake assessment of children and adolescents. British Journal
of Nutrition, 92: Suppl.2: S213-S222.
|Times Cited: 181
||Impact Factor: 3.013
Livingstone, M. B. E., Black, A. E. (2003). Markers of the validity of
reported energy intake. Journal of Nutrition, 133: Suppl 3:
|Times Cited: 348
||Impact Factor: 3.916
Black, A. E., Prentice, A. M., Goldberg, G. R., Jebb, S. A., Bingham, S.
A., Livingstone, M. B. E., Coward, W. A. (1993). Measurements of total
energy expenditure provide insights into the validity of dietary
measurements of energy intake. Journal of the American Dietetic
Association, 93: 572-579.
|Times Cited: 248
||Impact Factor: 3.586
Livingstone, M. B. E., Prentice, A. M., Coward, W. A., Strain, J. J.,
Black, A. E., Davies, P. S. W., Stewart, C. M., McKenna, P. G., Whitehead,
R. G. (1992). Validation of estimates of energy intake by weighed dietary
record and diet history in children and adolescents. American Journal
of Clinical Nutrition, 56: 29-35.
|Times Cited: 235
||Impact Factor: 6.669
Black, A. E., Goldberg, G. R., Jebb, S. A., Livingstone, M. B. E., Cole,
T. J., Prentice, A. M. (1991). Critical evaluation of energy intake data
using fundamental principles of energy physiology: 2. Evaluating the
results of published surveys. European Journal of Clinical Nutrition,
|Times Cited: 373
||Impact Factor: 2.462
Livingstone, M. B. E., Prentice, A. M., Strain, J. J., Coward, W. A.,
Black, A. E., Barker, M. E., McKenna, P. G., Whitehead, R. G. (1990).
Accuracy of weighed dietary records in studies of diet and health. British
Medical Journal, 300: 708-712.
|Times Cited: 213
||Impact Factor: 14.093
Grant income obtained to undertake the studies was from Department
of Health and Social Services for Northern Ireland (DHSS NI) and
Department of Health London (1987-1989):
Livingstone, M. B. E., Strain, J. J. Validation of diet histories. Funded
by DHSS (Clinical Award); 1989-1990; £5,350.
Livingstone, M. B. E., Strain, J. J., McKenna, P. G. (in collaboration
with the MRC Dunn Nutrition Unit, Cambridge). Validation of food intake
and energy expenditure in free living subjects in Northern Ireland. Funded
by DHSS; 1988-1989; £54,000.
Livingstone, M. B. E., Strain, J. J., Nathu, N., Nevin, G. B., Barker, M.
E., Hickey, R., McKenna, P. G. Studies of food intake and energy
expenditure in free living subjects in Northern Ireland. Funded by DHSS
(Clinical Award); 1988-1989; £4,050.
Livingstone, M. B. E., Strain, J. J., Nathu, N., Nevin, G. B., Barker, M.
E., Hickey, R., McKenna, P. G. Validation of food intake and energy
expenditure in free living subjects in Northern Ireland. Funded by DHSS;
Details of the impact
The categorical demonstration, for the first time, of substantial
under-estimation of food intake in randomly selected individuals was
revolutionary at the time. Not surprisingly, the nutrition community was
not initially convinced that bias in self-reported food intakes was a
major problem in dietary surveys and the paper by Livingstone et al
(1990) provoked a critical letter to the British Medical Journal (1).
However, as more validation studies were undertaken and published, the
initial findings were substantiated and there is now universal recognition
that mis-reporting in dietary surveys is pervasive. This issue, including
citation of the underpinning research, has now been highlighted in a
spectrum of reports and reviews published worldwide (2-5).
Now regarded as seminal work, the research has prompted a major paradigm
shift in the way policy makers interpret dietary intake data to establish
Dietary Reference Values for Food Energy and Nutrients and develop Food
Based Dietary Guidelines for Healthy Eating. Firstly, the papers by
Livingstone et al 1990; 1992) led to a radical shift in
thinking about dietary assessment techniques and initiated a new era in
research in the field. In continuing collaboration with the MRC Dunn
Nutrition Laboratory, Cambridge, researchers in the Northern Ireland
Centre for Food and Health went on to pioneer a cost effective way of
enabling researchers to critically examine their own data through
comparing energy intake data with estimated energy requirements based on
Basal Metabolic Rate (Black et al, 1991) This concept has been
hugely influential in spreading awareness about under-reporting and has
allowed dietary data to be examined in a much more critical way than
hitherto. The application of these principles has ensured a more critical
and informed interpretation of national dietary data [e.g. the UK National
Diet and Nutrition Survey (NDNS) (6); the US National Health and Nutrition
Examination Survey (7) which are widely used to establish nutrition
policy, to track progress toward achieving health and nutrition
objectives, to provide reference information on nutrition intakes, to
develop dietary guidance and to study diet-health relationships.
For example, average reported energy intakes in the UK are consistently
below the estimated average requirement, while paradoxically, the
prevalence of overweight and obesity has been increasing. However, this
anomaly is likely to reflect under-reporting of food intake given that it
has been estimated that under-reporting in the NDNS is approximately 25%
of energy needs and is particularly pronounced in the overweight and obese
(8). Consequently, in the face of compelling evidence about the extent and
magnitude of under-reporting of national dietary data, both the US
Institute of Medicine (2005) (9) and the UK Scientific Advisory Committee
on Nutrition (2011), when revising their respective energy reference
values for specific population groups, considered that it was no longer
tenable to base these on self-reported food intake data (8).
Another major problem in examining food intake data to derive Food Based
Dietary Guidelines for Healthy Eating is that of selective under-reporting
(either frequency of intake or serving size) of foods which are generally
perceived to be "bad for health". This reporting bias could either
attenuate or exaggerate associations between nutrient intake and health
parameters. For example, systematic under-estimation of dietary fat may
overestimate the positive association observed between percentage energy
from fat and health outcomes such as cancer and heart disease (10). Thus
differential biases in dietary reporting could have unpredictable
consequences and emphasise that improved assessment of dietary intake in
epidemiological studies is imperative for the future development of
evidence-based recommendations for diet and health.
In summary, the research described in this case study has been pivotal in
demonstrating that one of the most fundamental and intractable problems we
face in human nutrition research is our inability to measure what people
actually eat. Poor validity of dietary assessments has fundamental
implications for nutritional epidemiology and dietary surveillance. Biased
under-reporting of food intakes will inflate estimates of nutrient
inadequacies, attenuate risk estimates, obscure diet-disease associations
and ultimately generate misleading evidence on which to base public health
policy about healthy eating.
Sources to corroborate the impact
1) Jackson, A. A., Wootton, S. A. (1990). Accuracy of weighed dietary
records. Comment. British Medical Journal, 300: 1138-1139.
2) University of Otago and Ministry of Health. (2011) A Focus on
Nutrition: Key findings of the 2008/09 New Zealand Adult Nutrition Survey.
Wellington: Ministry of Health.
Available at: http://www.health.govt.nz/publication/focus-nutrition-key-findings-2008-09-nz-adult-nutrition-survey
[Accessed May 2013].
3) Roberts, K. (2010) Dietary Surveillance and Nutritional Assessment in
England: what is measured and where are the gaps? Oxford: National Obesity
Available at: http://www.noo.org.uk/uploads/doc/vid_5191_Dietary_Surveillance_and_Nutritional_Assessment_in_England.pdf
[Accessed August 2012].
4) The Institute of Medicine (2008) Nutrition Standards and Meal
Requirements for National School Lunch and Breakfast Programs: Phase I.
Proposed Approach for Recommending Revisions. Washington, DC: The National
[Accessed August 2012].
5) WSRO (2012) Position Statement Sugars and Micronutrient Dilution.
[Accessed May 2013]
6) Rennie, K., Coward, A., Jebb, S. Under-reporting of energy intake in
the National Diet and Nutrition Survey: Adults aged 19-64. Report of a
study commissioned by the Food Standards Agency and the Medical Research
7) Briefel, R. R., Sempos, C. T., McDowell, M. A., Chien, S., Alaimo, K.
Dietary methods research in the third National Health and Nutrition
Examination Survey: underreporting of energy intake. American Journal
of Clinical Nutrition, 1997;65 (suppl): 1203S-9S
8) Scientific Advisory Committee on Nutrition (SACN). (2011) Dietary
Reference Values for Energy. London: TSO.
Available at: http://www.sacn.gov.uk/pdfs/sacn_dietary_reference_values_for_energy.pdf
[Accessed May 2013].
9) The Institute of Medicine (2005) Dietary Reference Intakes for Energy,
Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein and Amino
Acids. Washington, DC: The National Academies Press.
Available at: http://www.nal.usda.gov/fnic/DRI/DRI_Energy/energy_full_report.pdf
[Accessed July 2013]
10) Heitman, B. L., Lissner, L. (2005) Can adverse effects of dietary fat
intake be overestimated as a consequence of dietary fat underreporting? Public
Health Nutrition, 8: 1322-1327.