Projects

Clarifying the Role of Weight Suppression and Dietary Restriction on Cognitive Flexibility Deficits in Eating Disorders

My PhD dissertation project aims to examine the extent to which weight suppression and restrictive eating are dimensionally associated with deficits in cognitive flexibility in individuals with and without eating disorders. Additionally, I will investigate whether dimensional indicators of severity such as weight suppression and dietary restraint, or DSM-5 diagnostic categories best explain individual differences in cognitive flexibility across individuals with eating disorders. For this project I am collecting data from a non-clinical student sample as well as a community sample of individuals with eating disorders. Findings could help to clarify whether weight loss and restrictive dieting are associated with cognitive flexibility even in the absence of an eating disorder, and whether weight and eating trajectories can be viewed as dimensional indicators of cognitive impairment across eating disorder diagnostic categories. Study design and hypotheses have been pre-registered. OSF

Early Clinical Intervention for Paramedics Following Operational Stress Injury

I am currently involved as a study therapist for a pilot trial examining potential benefits of rapid access to psychological services following work-related exposure to a potentially traumatic event. Paramedics are offered voluntary access to brief CBT (up to 3 sessions) within 48 hours of trauma exposure. Outcomes associated with mental health symptoms will be examined immediately post-treatment as well as 6/12-months later. Analyses will also examine associations between paramedic trait factors and intervention uptake and outcome. Study design and hypotheses have been pre-registered. OSF

Publications

*co-first author

Withnell, S. J., & Bodell, L. P. (2025). The moderating effect of weight loss intentions on dynamic associations between weight suppression and disordered eating. Eating Behaviors, 56. DOI

*Keast, R., Withnell, S., Bodell, L. P. (2023). Longitudinal associations between weight stigma and disordered eating across the weight spectrum. Eating Behaviors, 50. DOI

Withnell, S. J., & Bodell, L. P. (2023). Does suppressing weight improve body satisfaction? A longitudinal analysis in undergraduate men and women. Body Image, 45, 126-132. DOI

Withnell, S. J., Kinnear, A., Masson, P., & Bodell, L. P. (2022). How different are threshold and other specified feeding and eating disorders? Comparing severity and treatment outcome. Frontiers in Psychology, 13. DOI

Kinnear, A., Withnell, S. J., Witte, T. K., Smith, A. R., Szczyglowski, K., & Bodell, L. P. (2021). Weight misperception and its associations with eating disorder symptoms over the course of residential eating disorder treatment. International Journal of Eating Disorders, 54(10), 1810-1818. DOI

Withnell, S., Sears, C. R., & von Ranson, K. M. (2019). How malleable are attentional biases in women with body dissatisfaction? Priming effects and their impact on attention to images of women’s bodies. Journal of Experimental Psychopathology. DOI

Alberga, A. S., Withnell, S. J., & von Ranson, K. M. (2018). Fitspiration and thinspiration: A comparison across three social networking sites. Journal of Eating Disorders, 6(39). DOI

Presentations

2025

Withnell, S., & Bodell, L. (May 2025). Dynamic associations between weight suppression, weight loss intentions, and disordered eating, paper presented at 30th annual International Conference on Eating Disorders, San Antonio, USA.

2024

Withnell, S., & Bodell, L. (October 2024). Associations between weight loss, eating pathology and cognitive flexibility in a nonclinical sample, poster presented at Society for Research in Psychopathology annual meeting, Montreal, Canada.

2023

Withnell, S., Keast, R., & Bodell, L. (June 2023). Associations among disordered eating and experienced and internalized weight stigma across the weight spectrum, paper presented at 28th annual International Conference on Eating Disorders, Washington DC, USA.

2022

Withnell, S. J., & Bodell, L. P. (September 2022). Weight loss intentions do not moderate the prospective effects of weight suppression on body satisfaction and eating behaviors: A multilevel analysis, poster presented at 28th annual Eating Disorders Research Society Meeting, Philadelphia, USA.

Withnell, S., Kinnear, A., Masson, P., & Bodell, L. (June 2022). Comparing severity and outcomes in threshold and other specified feeding and eating disorders, snapshot presented at Canadian Psychological Association 83rd Annual National Convention, Calgary, Canada.

Withnell, S., & Bodell, L. (June 2022). Does maintaining a lower weight improve body satisfaction? A longitudinal analysis in undergraduate men and women, paper presented at 27th annual International Conference on Eating Disorders, Virtual.

2021

Withnell, S., & Bodell, L. (June 2021). Weight bias internalization and disordered eating: The mediating role of weight suppression, paper presented at the 26th annual International Conference on Eating Disorders, Virtual.

Withnell, S., & Bodell, L. (March 2021). Attempts to maintain weight loss mediate the relationship between internalization of weight stigma and disordered eating in women, oral presentation at the Western Research Forum (institutional graduate research conference), Virtual.

2017-2020

von Ranson, K. M., Withnell, S., & Sears, C. (May 2019). How malleable are body dissatisfaction-related attentional biases? Priming effects and the role of body appreciation, paper presented in symposium at the Canadian Psychological Association 80th Annual National Convention, Halifax, Canada.

Withnell, S., Sears, C., & von Ranson, K. M. (March 2019). Can attention to body-related images be modified by priming? A comparison of women with high and low body satisfaction, poster presented at the 24th annual International Conference on Eating Disorders, New York, USA.

Withnell, S., Sears, C., & von Ranson, K. M. (April 2017). Can attention to body-related images be modified by priming? A comparison of women with high and low body satisfaction, paper presented at the 21st annual Department of Psychology Student Conference, University of Calgary, CA