Effects of physical activity-related anti-weight bias materials on practitioner's implicit and explicit weight bias


Obesity Canada has created materials intended to provide positive portrayals of higher-weight individuals and to counter commonly held, erroneous, beliefs about obesity. Some of these materials are intended to dispel myths about the relationship between physical activity and obesity. This research investigated the effects of the physical activity-related videos and images, compared to a control video and control images, on implicit and explicit weight bias in physical activity practitioners. Participants (N = 129) were randomly assigned to view a physical activity or control video followed by Obesity Canada images or control images. They provided comments and rated each image as unhealthy/healthy, unfit/fit, and unmotivated/motivated and were asked if they would use the images in their work. Implicit weight bias was measured with single-category implicit association tasks and explicit weight bias with a questionnaire. Mean implicit and explicit bias scores were close to neutral and there were no differences in implicit or explicit weight bias between conditions. Participants who commented that they agreed with the physical activity video message had lower implicit and explicit weight bias. Higher ratings of the Obesity Canada images as healthy and fit were positively related to the likelihood of using them. Physical activity practitioners were less biased than reported by previous researchers, yet the pattern of results indicates that physical activity practitioners perceive active individuals with higher weight as less fit and healthy than active people with lower weight. The Obesity Canada materials had little impact on these perceptions.

Acknowledgments: This research was supported by the Canadian Institutes of Health Research