Electronic Thesis and Dissertation Repository


Doctor of Philosophy


Health and Rehabilitation Sciences


Dr. Jennifer D. Irwin and Dr. Don Morrow


The purpose of the CHANGE (Coaching towards Healthy Actions Naturally through Goal-related Empowerment) Program was to compare the effectiveness of an interactive versus prescriptive 12-week telephone-based behavioural intervention on the psychological and physiological profiles of university students with obesity. Motivational Interviewing administered using Co-Active Life Coaching (MI-via-CALC) and a structured lifestyle treatment following the LEARN (Lifestyle, Exercise, Attitudes, Relationships, Nutrition) Program for Weight Management were examined.

Article 1 provided a methodological account of the CHANGE Program which included a detailed rationale for its development and a comprehensive description of the methods used. Because goal setting has been established as an accessible and empowering tool to evoke health behaviour changes, Article 2 explored systematically the utility of this strategy in adults with overweight and obesity. Findings were used, in part, to inform the development of the CHANGE Program.

The purpose of Article 3 was to compare the impact of MI-via-CALC with the LEARN Program on the quality of life and self-esteem of participants during the intervention, and three- and six-months following its completion. Significant improvements to both dimensions were observed across the groups between baseline and the follow-up periods. Article 4 compared the effectiveness of the interventions from a self-management perspective on anthropometric, blood lipid profiles, and dietary risk factors associated with the development of type 2 diabetes. A qualitative exploration of participants’ experiences was also undertaken. A significant time effect was observed for weight with the LEARN group decreasing more than the MI-via-CALC group during the intervention while MI-via-CALC participants decreased their calories consumed more than LEARN participants during this same time. Qualitatively, the MI-via-CALC group focused on self-understanding, and -responsibility as primary outcomes of their experience; the LEARN group stressed their appreciation of practical knowledge gained.

This is the largest MI-via-CALC study conducted to date and the first to incorporate specific measures of physiological determinants, and a validated comparison group. MI-via-CALC compared favourably with LEARN as a treatment for obesity indicating that both are warranted in isolation or in combination with one another. The best fit and unique contributions of each approach should be considered when working with this population.