Objective: The purpose of this review is to provide guidance on the development, validation and use of food-frequency questionnaires (FFQs) for different study designs. It does not include any recommendations about the most appropriate method for dietary assessment (e.g. food-frequency questionnaire versus weighed record). Methods: A comprehensive search of electronic databases was carried out for publications from 1980 to 1999. Findings from the review were then commented upon and added to by a group of international experts. Results: Recommendations have been developed to aid in the design, validation and use of FFQs. Specific details of each of these areas are discussed in the text. Conclusions: FFQs are being used in a variety of ways and different study designs. There is no gold standard for directly assessing the validity of FFQs. Nevertheless, the outcome of this review should help those wishing to develop or adapt an FFQ to validate it for its intended use.

A review of the literature concerning the design, utilisation and validation of food-frequency questionnaires (FFQ) has been carried out using a semi-systematic approach to obtaining, reviewing and extracting data from articles. Databases were searched from 1980 to 1999. The present review identified 227 validation (from 1980 to September 1999) and 164 utilisation (for 1998 only) studies. A number of design issues have been evaluated through the present review. These include: the need to consider how portion sizes have been described, self-defined giving higher mean correlations; how an FFQ was administered, interviewer-administered giving higher mean correlations for some nutrients; how many items to include on an FFQ, those with the largest number of items having higher correlations. Validation techniques were described. Most validation studies involved comparing an FFQ against another dietary assessment method; only 19 % compared an FFQ to a biomarker. Measurement differences were most commonly assessed by correlation coefficients as opposed to other more appropriate methods. Mean correlation coefficients were highest for Ca and fat, and lowest for vitamin A and vegetables. The utilisation studies showed that FFQ were most commonly used in cross-sectional surveys, with ninety-three of the FFQ being designed to be disease-specific. The present review results were presented to a group of experts and a consensus arrived at concerning the development, validation and use of FFQ. Recommendations derived from the consensus arising from the literature review are presented as an appendix to the present paper. Food-frequency questionnaires: Validation: ReproducibilityAbbreviations: FFQ, food-frequency questionnaire; OR, odds ratio. * Corresponding author: Dr J. E. Cade, fax +44 113 343 3470, email j.e.cade@leeds.ac.uk IntroductionDuring the 1950s and 1960s nutritionists started to develop questionnaires for the assessment of habitual food intake based on a checklist of foods consumed over a set time period because of problems encountered with 24 h recall techniques and weighed inventories. After further refinement, revision and appraisal during the 1980s and 1990s, food-frequency questionnaires (FFQ) have become one of the key research tools in nutrition epidemiology. However, despite considerable advantages in terms of ease of administration and analysis, FFQ may be limited in their usefulness and, through poor design and inappropriate use, may not yield the required information. No dietary method can measure dietary intake without error (Margetts & Nelson, 1997) so it is important that sources of error are taken into account. No formal systematic review of the FFQ method has been carried out to date. The present study has brought the results of research together to evaluate the method and assess 'best practice' for further studies. MethodologyA systematic review approach (Chalmers & Altman, 1995) was developed to identify relevant studies describing the design, evaluation and/or use of FFQ. The definition of an FFQ w...

Abstract. Within a context of public policy debate in the United Kingdom on social exclusion, health inequalities, and food poverty, the metaphor of the`food desert' caught the imagination of those involved in policy development. Drawing from a major cross-disciplinary investigation of food access and food poverty in British cities, the authors report in this paper findings from the first`before/after' study of food consumption in a highly deprived area of a British city experiencing a sudden and significant change in its food-retail access. The study has been viewed as the first opportunity in the United Kingdom to assess the impact of a non-healthcare intervention (specifically a retail-provision intervention) on food-consumption patterns, and by extension diet-related health, in such a deprived, previously poor-retail-access community. The paper offers evidence of a positive but modest impact of the retail intervention on diet, and the authors discuss the ways in which their findings are potentially significant in the context of policy debate.

If poor food retail access in deprived areas of British cities is linked, as suggested in many of the policy debates of the late 1990s, via compromised diets/undernutrition to poor health and widening health inequalities, what is the impact of a sudden and significant improvement in food retail access likely to be on the food consumption patterns of residents? In this paper, we describe and provide preliminary results from the first-ever UK study of a major retail provision on diet in a 'food desert'—a 'before/after' study of food consumption patterns in the highly deprived, previously poor food retail access area of Seacroft, Leeds, experiencing a sudden and significant change in its food retail access as a result of the opening of a large superstore by the UK's leading food retailer. We suggest that this study has the potential to provide some of the missing links between poor food retail access, compromised diets/undernutrition, poor health and compound social exclusion that characterised statements on the topic of 'food deserts' in the health inequalities and social exclusion debates of the late 1990s, and that its findings may have significant implications for policy debate.