All are invited to the CEDAR/MRC Epidemiology Seminar:

Professor Tim Olds, School of Health Sciences, University of South Australia
Building your best day: combining compositional analysis and optimisation theory
MRC Epidemiology Unit meeting rooms 1 and 2, Institute of Metabolic Science, Cambridge Biomedical Campus

Abstract

The foundational principle of behavioural epidemiology is that the way we use our time— physical activity, sleep, sitting, social interactions — affects our health, everything from asthma to eczema. Typically these studies have been done by regressing a health outcome (say depression) against a behavioural domain, such as physical activity. However, because time use data are co-dependent, any change in time allocated to one domain must be matched by an equal and opposite allocation to the other domains collectively. This presentation will show some examples of the application of compositional data analysis (CoDA) as a new approach to time-use data. By combining CoDA with optimisation theory, we can move towards specifying the best possible 24-hour day for any given health outcome or set of outcomes.

About Prof Olds

Tim Olds is a professor of behavioural epidemiology at the University of South Australia. After completing a PhD in French Studies at the University of Sydney, Tim went on to study exercise science, receiving a second PhD in 1997. His research interests have been in mathematical modelling of cycling performance; population and sports anthropometry; secular trends in the sleep, fitness, fatness, physical activity and food intake of children and adolescents; and the relationship between how people use their time and health. Tim has $27m in grants and 292 publications. http://people.unisa.edu.au/timothy.olds