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Key Contact:  Dr. Robert Moran, rrmoran@gwm.sc.edu, 803-251-7876

Focus of Activities
The Diet Assessment Research Unit (DARU) is a resource to assist researchers design, collect, process, and analyze information on dietary habits and nutrient intake. The 2 major purposes for assessing dietary intake include: 1) To assess the role of diet in health and 2) to evaluate the effectiveness of intervention strategies in modifying diet. For assessing the role of diet in health, we may suggest the use of custom-designed food frequency questionnaires (FFQ) that can focus on the overall diet or some subset of foods or nutrients to capture information on usual diet. For evaluation of an intervention, we may suggest using a structured assessment instrument such as the FFQ, but more commonly we will assess individual nutrient intake using the 24-hour recall interview (24HR) to capture current diet, especially for intensive interventions

Consultation and Statistical Analysis of Dietary Intake Data
The Diet Assessment Research Unit can provide expert consultation on study design, diet assessment strategies, and the statistical analysis of dietary data. Areas where our group has extensive experience include design and validation of dietary assessment instruments, with an emphasis on identifying and adjusting for self-report bias.

Diet Assessment tools
Twenty - four Hour Diet Recall Interviews (24HR)
Used mainly in interventional research, the 24HR can be administered in person or over the telephone. We use the Minnesota Nutrition Data System (NDSR version 4.06_34), a state of the art interview and food table system developed by the University of Minnesota. Each interview takes 20-30 minutes to complete. Registered Dietitians trained in the multi-pass interviewing technique conduct the interviews. A single day is adequate for estimating the diet of a group, but a minimum of three days is necessary to estimate nutrient intake of the individual for the most easily characterized nutrients. Additional 24HR may be required depending on the nutrient of interest. With a sufficient number of recall days the 24HR is the assessment method with the lowest total measurement error. There is a great variety in the types of output data sets that can be created. They consist of nutrient data, food data, or both. Data sets can be output in any format the client specifies.


Food Frequency Questionnaires
This method is the mainstay of work in observational epidemiology. We design instruments to capture specific nutrients and modify them to conform to the specific needs and requirements of study populations. We have had extensive experience with developing and testing a range of structured questionnaires, including FFQs used in a variety of research and practice settings. In addition to developing and testing these instruments, we have identified ways to improve precision and accuracy in epidemiologic studies by identifying relevant biases and developing methods of control when performing statistical analyses. Theoretically, a single administration of an FFQ provides an estimate of usual, habitual intake. Administration takes about 30-45 minutes to complete and can be either a self-administered or interviewer-administered instrument. The forms are optically scannable. Output data sets can consist of either food or nutrient data, depending on the needs of the researcher.

NCI Fat and Fruit and Vegetable Screening Instruments and other short list FFQs
In some research settings a short, list-based instrument is required to assess dietary habits with a minimum of time and respondent input. We have experience working with the NCI-developed screeners and other short-list instruments. These instruments can be self-administered or conducted by an interviewer.