Department of Statistical Science
Duke University
presents:
Alicia Carriquiry
alicia@stat.duke.edu
Iowa State University
"Analysis of Dietary Intake Data"
Abstract: The distribution of usual intakes of dietary components is important to those formulating food policy or designing nutrition education programs. The usual intake of a dietary component for a person is defined as the long-run average of daily intakes of the dietary component for that person, and is not directly observable. Thus it is necessary to estimate the distribution of usual intakes in the population from a sample of individuals who report their food consumption for a small number of days. Daily intake data are nonnegative and often very skewed. Further, the within individual variation in intakes can be larger than the between individual variation, and within individual variances can be heterogeneous and correlated with individual mean intake. We have developed a method for estimating the distribution of usual intakes for any dietary component. From a statistical point of view, the problem is one of estimating the density of a random variable that is subject to measurement error. The method was originally developed for the case of nutrients such as energy, calcium, and vitamins, but has since been extended to permit estimation of usual intake distributions of foods and of ratios of nutrients (such as the percent calories consumed from fat). This work is the result of a long-term cooperative agreement between the Agricultural Research Service of the USDA and Iowa State University, which was recently finalized. We are currently cooperating with the Department of Health and Human Services, and with the National Academy of Sciences (Food and Nutrition Board) and continuing with research in this and related areas.
April 25, 1997
4:00 pm - 5:00 pm
116 Old Chem Building Any questions concerning the seminar may be addressed to Cheryl McGhee @ [919] 684-8029 or e-mail cheryl@stat.duke.edu. Please contact the author(s) directly for reprints etc.