Dietary Data Decoded

This course deals with identifying and correcting for measurement error in dietary intake assessment, the core of nutrition surveillance and nutritional epidemiolgy studies.

Focus is on design and analysis of evaluation studies which assess measurement error in dietary intakes. You will learn how to adjust study results from nutritional surveillance and etiological studies for these measurement errors. Nutrition research is often blamed for poor exposure assessment that might impair its usefulness. For example it has often been argued that FFQs are not useful to detect weak associations between dietary intake and health outcomes, since estimates of these associations are affected by errors in the exposure assessment. Despite their measurement errors, FFQs are commonly applied in epidemiological studies, as they are considered a feasible and cost-effective dietary assessment method. Evaluation studies (e.g. reproducibility and validation studies) can help to quantify measurement errors in dietary exposure assessment, in order to adjust research outcomes (e.g. associations between intake and health/disease or nutrient recommendations) for those errors and to adapt dietary assessment methods. Therefore such evaluation studies are essential to incorporate in nutritional research such as large cohort studies, case-control studies, surveillance studies etc. Consequently it is crucial for you as future researcher or practicing nutritional epidemiologist, to get training on the design, analyses and interpretation of studies which aim to valuate dietary assessment methods. In addition, this course will discuss different ways of dietary exposure, specifically dietary patterns. You will get hands-on experience with dietary pattern analysis.

• Design and develop food frequency questionnaires

• Design an evaluation study to compare the performance of a food frequency questionnaire against one or more reference methods

• Explain the aims and principles of evaluation studies in the context of nutritional research

• Understand how errors in dietary assessment affect the interpretation of results from nutrition surveillance and nutritional epidemiology and how evaluation studies can be used to obtain estimates of potential errors

• Understand the analysis of evaluation studies on dietary assessment, including the use of biomarkers in nutritional epidemiologic research

• Have a basic understanding of dietary pattern analysis

• Written test with open and closed questions (60%)
• Assignment other (40%) Protocol evaluation study. Assignments are made individually for distance learning and in groups for on campus students. In case of late submission, the assignment has to be re-done during the course in the following academic year. In case of failed submission, possibilities for a re-sit are discussed in consultation between the students and the course coordinator.
• Assignment other (0%) Peer review. For distance learning students only. Pass/fail.

HNE293030 Measuring dietary intake. HNH25806 Research Methodology for Nutrition and Health I and HNH26306 Research Methodology for Nutrition and Health II or HNH24306 Methodology Nutrition Research; HNH24806 Introduction to Epidemiology and Public Health; MAT20306 Advanced Statistics or MAT24306 Advanced Statistics for Nutritionists. For this course you need to have basic knowledge on the statistical data analysis software R.

• Book: Willett, W. (2012). Nutritional Epidemiology. Monographs in Epidemiology and Biostatistics, 3rd revised ed. ISBN 13: 9780199754038.