227538 Mediators of weight loss in a podcast delivered health communication intervention

Monday, November 8, 2010

Linda Ko, PhD, MS, MPH , Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC
Gabrielle Turner-McGrievy, PHD, MS, RD , Department of Nutrition, University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Chapel Hill, NC
Marci K. Campbell, PhD, MPH, RD , Department of Nutrition, University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Chapel Hill, NC
Background: A weight loss intervention with portable electronic media has been effective among overweight or obese adults. Little is known on how this intervention works to exert its effect. We investigated whether information processing (IP) domains of user control, cognitive load, and elaboration are mediators of weight loss in a podcast-delivered intervention.

Methods: 77 individuals were interviewed at baseline and randomized to a podcast (control group) or theory-based podcast (TBP) intervention. 66 completed the follow-up survey at 12 weeks. A path model was constructed to observe the relationship between intervention groups, IP, and weight loss.

Results: TBP was directly related to weight loss. Individuals in the TBP lost more weight compared to the control group (b=-0.086, p<.05). TPB was also indirectly related through user control, cognitive load, and elaboration through three pathways. This model had a good fit (X2 (6, N=66)=5.59, CFI=1.00, TLI=1.00, RMSEA=.00, and WRM=.03). In the first path, TBP was related to greater user control (b=0.39, p<.01). Greater user control was associated with greater elaboration (b=0.43, p<.001). Greater elaboration, in turn, was related to greater weight loss (b=-0.10, p<.01). In the second path, TBP was related to decreased cognitive load (b=-0.54, p<.001). Lower cognitive load was associated with greater elaboration (b=-0.22, p<.01), and elaboration was related to weight loss (b=-0.10, p<.01). Lastly, TBP was related to elaboration (b=0.30, p<.001), and greater elaboration to weight loss (b=-0.10, p<.01).

Conclusions: Efforts to enhance users' control and decrease cognitive load should be consider to increase elaboration in future weight loss interventions.

Learning Areas:
Administer health education strategies, interventions and programs
Systems thinking models (conceptual and theoretical models), applications related to public health

Learning Objectives:
1. Identify information processing theories and variables relevant for weigh loss interventions 2. Describe the relationship between information processing of a podcast intervention and weight loss. 3. Demonstrate the potential causal pathways between information processing domains and weight loss

Keywords: Health Communications, Obesity

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I am qualified to present because I conduct research on health communication, information processing, and weight loss.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.

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