Evaluation of Dietary Intake

Data which identify food consumption are collected for a variety of reasons:

• to estimate the adequacy of dietary intake of the population

• to investigate the relationship between diet, nutritional status and health.

• to evaluate nutritional education, intervention and food fortification programmes

Information is obtained on food and dietary intake by individuals or groups of individuals either by methods of measuring food intake or by methods of converting food intake to nutrient intake.

1. Food consumption data are collected to identify whether the population is eating sufficiently well, to assess the relationship between diet, health and nutritional status and to plan nutritional education, intervention and food fortification programmes.

2. A correct measurement of dietary intake is central to any nutritional epidemiological study. The validity of the results must be checked and error estimated so that allowances can be made in the final analyses.

3. Prospective records of food intake are more accurate than recall of past intake.

4. A number of techniques have been described including description, weighed and estimated records, measurement of intake, diet history, household data and inventory methods. Other methods include household records, list-recall methods and population studies and 7-day measurement of food intake, with anthropometric measures and blood constituents. Individual diet histories and 24-hour recall are important assessments of nutritional intake. The accuracy of food frequency questionnaires can be assessed.

5. The conversion of food consumption to nutrient intake is a complex process which requires chemical analyses of the various food constituents, the writing of food consumption tables and analysis of individual foods.

Further reading

Bingham, S.A. and Nelson, M. (1991) Assessment of food consumption and nutrient intake, in Design Concepts in Nutritional Epidemiology (eds B.M. Margetts and M. Nelson), Oxford Medical Publications, Oxford University Press, Oxford.
Black A, Welch A, Bingham SA ( 2000) Validation of dietary intakes measured by diet history against 24h urinary nitrogen excretion and energy expenditure measured by the doubly-labelled water method in middle aged women. British Journal of Nutrition 83, 341-354
Brunner E , Stallone D, Juneja M, Bingham S, Marmot M ( 2001) Dietary assessment in Whitehall II: comparison of 7d diet diary and food frequency questionnaire and validity against biomarkers. British Journal of Nutrition , 86, 405-414.
Crew H, Alink G, Andersen R et al (2001) A critical assessment of some biomarker approaches linked with dietary intake. British Journal of Nutrition86, S5-S35
Hudson G (1995). Food intake in a West African village. Estimation of food intake from a shared bowl. British Journal of Nutrition 73, 551-569
Lissen L, Heitmann BL and Lindroos LK ( 1998) Measuring intake in free-living human subjects: a question of bias. Proceedings of the Nutrition Society 57, 333-339.
McCance and Widdowson’s The Composition of Foods .( 1991). B Holland, AA Welch, ID Unwin, DH Buss, AA Paul, DAT Southgate, Ministry of Agriculture, Fisheries and Food and The Royal Society of Chemistry The Royal Society of Chemists. 5th ed
Macdiarmid J and Blundell J. (1998 ) Assessing dietary intake : who, what and why in under reporting. Nutrition Research Reviews 11; 231-253. .
Nelson M ( 1995 ) Editorial – Can we measure what people eat ? Journal of Human Nutrition and Dietietics 8, 1-2
Posner, R M., Franz, N. and Quatromoni, P (1994) Nutrition and the global risk for chronic diseases The Inter Health Nutrition Initiative. Nutrition Reviews52, 201–7.
Rush D ( 1997) Nutrition Screening in old people: its place in a coherent practice of preventive health care. Annual Review of Nutrition 17: 101-25
Slater JM ed Fifty years of the National food survey 1940-1990. ( 1991)London HMSO
West, C.E. and van Staveren, WA. (1991) Food consumption, nutrient intake, and the use of food consumption tables, in Design concepts in Nutritional Epidemiology (eds B.M. Margetts and M. Nelson), Oxford Medical Publications, Oxford University Press, Oxford.


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