National Cancer Institute
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Risk Factor Monitoring & Methods
Cancer Control and Population Sciences


Assessing Dietary Intakes: Current Projects & Research

The Risk Factor Monitoring and Methods Branch (RFMMB) conducts extensive research on the development, use, and evaluation of food frequency questionnaires (FFQs) and statistical methods to assess usual dietary intake.

The design and accuracy of FFQs is an important issue because these instruments are commonly used in epidemiological research to evaluate the relationship of diet to outcomes such as cancer, heart disease, or other chronic diseases. FFQs are also used in dietary interventions or in public health settings to monitor or evaluate absolute intakes. FFQs consist of a list of foods about which individuals are asked to record usual frequency of intake over a specified period of time (such as the past year). FFQs vary in length, but often include more than 100 food items. Questions about usual portion size are often, but not always, included. In addition to questions about food intake, FFQs often include questions about vitamin, mineral, or other dietary supplement use.

Current Projects

Since the mid-1990s, we have worked to improve and validate FFQs for epidemiological and public health research. We have developed an FFQ, called the Diet History Questionnaire (DHQ), for use by researchers and others. Along with its associated software, Diet*Calc, the DHQ can be used to estimate nutrient and food group intakes of individuals. We have conducted several studies to evaluate the DHQ and other FFQs:

  • The Eating at America's Table Study was a 1997-1998 validation study of the DHQ that compared the DHQ to two other FFQs in wide use at that time. EATS used 24-hour dietary recalls as the reference instrument. We are currently analyzing EATS data in two analyses: 1) a validation study of Food Guide Pyramid food group intake using four 24-hour dietary recalls as the reference instrument, and 2) a study of the relationship of blood biomarkers to reported FFQ intakes of carotenoids and tocopherols in a subgroup of participants.
  • The Observing Protein and Energy Nutrition Study is a biomarker-based study using the DHQ, 24-hour dietary recalls, doubly labeled water to measure energy expenditure, and 24-hour urines to measure nitrogen, sodium, and potassium intakes. This study was designed to assess the the structure of measurement error associated with FFQs and 24-hour dietary recalls. Although several papers from OPEN are already published we are continuing to analyze these data to assess 1) the impact of energy adjustment on measurement error, 2) food intake reporting differences between low- energy reporters compared to accurate reporters, and 3) reporting issues related to body mass index.
  • The Re-OPEN Study is a study in which OPEN Study participants were recontacted to further assess measurement error issues related to food records and a combined food frequency questionnaire and a 7-day checklist. These data are currently being collected and will be available for analysis in Fall 2004.
  • The Women's Health Initiative Ancillary Study of the Relative Risk Differences between FFQs and Food Records will assess whether relative risk findings differ between two dietary assessment instruments, the FFQ and food records, conducted at baseline among approximately 600 breast cancer cases and 1,200 controls.

We are also developing an improved method of assessing long-term average, or "usual" dietary intake that builds on the strengths of both FFQs and 24-hour dietary recalls. As part of this effort, we have developed the NHANES Food Frequency Questionnaire (formerly called Food Propensity Questionnaire), which is similar to the DHQ but without portion size questions. This FFQ was pilot tested for the National Health and Nutrition Examination Survey (NHANES) and was introduced in the NHANES in 2003.

Last modified:
04 Feb 2008
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