Tamara Cohen

Assistant Professor

Research Interests

understanding the interplay between different lifestyle behaviours
how eating behaviours relate to weight management
Obesity

Relevant Thesis-Based Degree Programs

 
 

Graduate Student Supervision

Master's Student Supervision

Theses completed in 2010 or later are listed below. Please note that there is a 6-12 month delay to add the latest theses.

Assessing the suitability of nutrition education resources on sugar among dietitians (2024)

Background: Registered dietitians (RD) use nutrition education resources to educate themselves and their patients to understand various nutrition topics. Research has shown that RDs have perceived barriers towards using the Canadian Sugar Institute’s (CSI) resources, and the suitability of their resources for use by RDs has yet to be explored. Objectives: The primary objective of this study was to conduct suitability testing of nutrition education resources for RDs that centre on sugars and health. The secondary objective was to develop a series of recommendations in the form of a “checklist” that can be used to create and/or refine current nutrition education resources.Methods: This study recruited RDs to virtually assess two nutrition education resources (one on sugars and metabolic disease and the other on sources of sucrose) using the adjusted Suitability Assessment of Materials (SAM) through three iterative rounds. SAM evaluates resources based on Content, Literacy Demand, Graphic Material, Layout & Typography, Learning, Stimulation & Motivation, and Suitability and has participants rank the subscales as ‘superior’, ‘adequate’, or ‘not suitable’. A checklist was created to help CSI refine the resources between each survey round. Participants re-evaluated the refined resources using the SAM. Descriptive statistics and one-way ANOVA were performed to explore differences among total SAM scores between surveys.Results: RDs (n=45, n=37, n=27) participated in the first, second, and third surveys, respectively. The total SAM score of Resource 1 improved from 66.61 ± 16.0% (‘adequate’) in Survey 1, to 72.71 ± 14% (‘superior’) in Survey 2, to 78.83 ± 16% (‘superior’) in Survey 3 (p=0.007). The total SAM score of Resource 2 improved from 70.55 ± 18% (superior) in Survey 1 to 72.78 ± 16% (superior) in Survey 2, to 81.98 ± 16% in Survey 3 (p=0.016).Conclusion: Overall, rankings of CSI’s RD-facing resources improved after refinements were made using the checklist. Future studies are needed to test the use of the checklist in improving other resources intended for RDs on different nutrition topics.

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Metabolically healthy obesity in children attending pediatric weight-management programs in Canada (2023)

Background: Childhood obesity continues to be a global health concern.¹ Health risks associated with childhood obesity include hypertension and orthopedic disorders, among others.² However, not all children with obesity present with obesity-associated health risks.³,⁴ These health risks are thought to be part of one’s obesity phenotype.⁵ Distinguishing among them may lead to better treatment and management strategies.⁶⁻⁸ For this reason, obesity without metabolic syndrome health risk factors (i.e., lowered HDL, elevated triglycerides, blood pressure, fasting glucose) is known as metabolically healthy obesity (MHO), and those with abnormal metabolic markers are classified as metabolically unhealthy obesity (MUO).⁵,⁹ Objectives: Using data from the CANadian Pediatric Weight-Management Registry (CANPWR), this thesis aims to (i) establish the prevalence of MHO in participants 6-17 years old at baseline and one-year follow-up; and (ii) explore which health behaviour factors (diet, physical activity, sedentary, and sleep behaviours) are associated with MHO status. Methods: This secondary analysis included participants (n = 387, 52.7% female; mean age: 12.8 ± 2.9 years). Questionnaires were used to capture all non-metabolic variables. T-tests and chi-square tests were used to analyze continuous and categorical variables. Anthropometrics and biochemical assessments occurred at CANPWR sites at baseline and 1-year. Results: At baseline, n = 135 (34.9%) of participants were classified as MHO; n = 254 (65.1%) were identified as MUO. At follow-up, a similar percentage were classified as MHO (34.4%) and MUO (65.6%). However, n = 108 (27.9%) participants who were MHO at baseline presented as MUO at follow-up. Reported lifestyle behaviours that significantly differed for MHO/MUO were inconsistent at baseline and follow-up (baseline: fruit juice intake, weekly screen time hours, computer/video game hours; follow-up: fruit, ice cream/frozen yogurt intake). A lower BMI z-score was associated with MHO at both baseline and follow-up. Conclusion: The overall prevalence of MHO and MUO was similar at baseline and follow-up. Further analyses revealed variables that predicated this switching of status. This study highlights the need for more research in assessing metabolic health of children who are referred to weight-management programs, as children can present with worsening of metabolic health status at follow-up.

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Perceptions of a dietary self-monitoring mobile app resembling the Canada’s food guide : a qualitative study (2023)

Background and Purpose: Dietary self-monitoring is a behavioural technique that helps to elicit and sustain dietary changes over time. Current dietary self-monitoring tools focus on itemizing foods and serving sizes (portions), making them complex, time-consuming, and hard to use for people with limited or low health literacy. Furthermore, there are no plate-based dietary self-monitoring tools that conform to the 2019 Canada Food Guide (CFG). This thesis explored the perceptions of potential end-users (i.e., members from the general public) and Registered Dietitians (RDs) on a dietary self-monitoring mobile application (app) resembling the CFG, called iCANPlateᵀᴹ.Methods: Qualitative data were collected through virtual focus groups. Questions in the focus group guide were based on the Capability, Opportunity, Motivation- Behaviour (COM-B) model to explore perceptions of using the CFG and available dietary self-monitoring tools. A prototype of iCANPlateᵀᴹ (version 0.1) was presented to gain feedback on perceived barriers and facilitators to using the app, and suggestions on future versions. Trained researchers used transcripts of audio-recorded focus groups to conduct thematic analysis.Results: Seven focus groups with RDs (n=44) and nine focus groups with members from the general public (n=52) were conducted. During the focus groups, participants discussed potential facilitators and barriers to using the current iteration of iCANPlate. They were interested in the simplicity of iCANPlate and its capacity to foster self-awareness of dietary behaviours rather than weight or calorie counting. However, concerns were raised regarding iCANPlate’s potential to improve adherence to dietary self-monitoring, primarily caused by a lack of food classifications, conceptualizing proportions, and lack of inclusivity. In addition, participants suggested necessary and optional components for iCANPlate’s future versions. Conclusions: Overall, participants liked the simplicity of iCANPlate and its ability to promote self-awareness of dietary intakes, primarily through visual representation of foods on a plate as opposed to reliance on numerical values or serving sizes. Findings from this study will be used to further develop the app with the goal of increasing adherence to plate-based dietary approaches.

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