Dr Sarah-Jane Stewart

PhD Student and Trainee Health Psychologist
9am-5pm, Monday to Friday (06AC04)

Academic and research departments

School of Psychology.

My research project

My qualifications

September 2013 - July 2017
BSc (HONS) Psychology, First Class
University of Surrey
September 2017 - September 2018
MSc Health Psychology, Distinction
University of Surrey

Affiliations and memberships

Division of Health Psychology, British Psychological Society
In-training graduate member

My teaching

My publications


Jane Ogden, Bobo Cheung, Sarah‐Jane F. Stewart (2020)A new measurement tool to assess the deliberate overfeeding of others: The Feeder questionnaire, In: Clinical Obesitye12366 Wiley

Whilst overeating is often influenced by others in an implicit way, people may also explicitly encourage others to overeat. This has been labelled being “a Feeder” but to date, this more deliberate trait remains neglected. This study aimed to conceptualize being “a Feeder” in terms of motivations and behaviour and to operationalize this construct with a new measurement tool through five stages with three discrete samples. Using the definition of a Feeder as “someone who offers others food even when they are not hungry” a preliminary qualitative study (n = 5) clarified the behaviour of a Feeder and revealed six motivations for such feeder behaviour. These six motivational dimensions and the feeder behaviours were operationalized with individual items and the psychometric properties of the scale were assessed using two independent samples (n = 116; n = 113). The final 27‐item measure consisted of six motivational factors (affection; waste avoidance; status; hunger avoidance; offloading; manners) and one behaviour factor, all with good internal consistency (α  ≥ .7). The two samples were then merged (n = 229) to describe motivations and behaviour and to assess the association between them. The best predictors of feeder behaviour were love, offloading, manners and status. This new Feeder questionnaire has a strong factor structure and good internal consistency and could be used for further research or clinical practice.

Sarah-Jane Stewart, Jane Ogden (2020)The impact of body diversity vs thin-idealistic media messaging on health outcomes: an experimental study, In: Psychology, Health & Medicineahead-of-print(ahead-of-print) Taylor & Francis

The recent rise in body dissatisfaction and weight bias has led to a call to the media to increase the diversity of their imagery, in efforts to challenge the thin-ideal. Therefore, this study aimed to evaluate the effects of both body diversity and thin-ideal interventions on health outcomes. Female participants (n = 160) were randomly allocated into an intervention group: body diversity; thin-ideal; control. They completed measures of body satisfaction, body compassion, internalisation of the thin-ideal, weight bias and behavioural intentions at baseline and post-intervention. The results showed significant differences between groups for weight bias and intentions to eat healthily. Specifically, those in the body diversity intervention group reported a greater reduction in weight bias compared to the other conditions. Further, those in the thin-ideal intervention group reported a greater increase in intentions to eat healthily compared to the other conditions. There were no differences between groups for body satisfaction, body compassion, internalisation of the thin-ideal and behavioural intentions to exercise and manage weight. In conclusion, exposure to body diversity images reduced weight bias whereas exposure to the thin-ideal promoted intentions towards healthy eating. These findings therefore offer empirical evidence for the impact of using different types of imagery to change different health outcomes.

This experimental study investigated the role of BMI on the impact of weight bias versus body positivity terminology on behavioural intentions and beliefs about obesity. Participants (n=332) were randomly allocated to two conditions to receive a vignette depicting an image of a person with obesity using either weight bias (n=164) or body positivity (n=168) terminology. Participants were divided into 3 groups based upon their BMI category (normal weight n=173; overweight n=92; obese n=64). They then completed measures of behavioural intentions, obesity illness beliefs and fat phobia. Although there were several differences in beliefs by BMI group, the results showed no differences between weight bias or body positivity terminology on any measures. There were, however, significant BMI group by condition interactions for beliefs about obesity relating to personal control and treatment control. Post hoc tests showed that weight bias resulted in reduced personal control in the obese BMI group compared to other participants. Weight bias also resulted in higher personal control over obesity in normal weight individuals compared to body positivity. People with obesity reported higher treatment control when exposed to weight bias compared to overweight participants, whereas normal weight participants reported greater treatment control when exposed to body positivity compared to both other groups. To conclude, the impact of weight bias and body positivity information is not universal and varies according to the BMI of the audience and the outcome being measured; whereas people of normal weight may benefit from weight bias there is no evidence that obese people benefit from body positivity. Implications for the prevention and treatment of obesity are discussed.

SARAH-JANE FRANCES STEWART, JANE E OGDEN (2021)What are weight bias measures measuring? An evaluation of core measures of weight bias and weight bias internalisation, In: Health Psychology Open SAGE Publications

Research exploring weight bias and weight bias internalisation (WBI) is grounded upon a number of core measures. This study aimed to evaluate whether operationalisations of these measures matched their conceptualisations in the literature. A ‘closed card-sorting task’ methodology was used whereby participants sorted items from the most commonly used measures into pre-defined categories, reflecting weight bias and non-weight bias domains. Findings indicated a high degree of congruence between WBI conceptualisations and operationalisations. However, there was less congruence between weight bias conceptualisations and operationalisations, with scale-items largely being sorted into non-weight bias domains. Recommendations for scale modifications and developments are made, and a new amalgamated weight bias scale (AWBS) is presented.

Purpose: To explore how individuals with overweight and obesity living in the UK respond to the public health and media messaging surrounding COVID-19 and obesity. Design: Qualitative interview study with a think-aloud protocol. 10 participants self-reported to have overweight, obesity, or as actively trying to lose weight were recruited through social media, were asked to think-aloud whilst exposed to four sets of public health and media materials describing the link between COVID-19 and obesity. Interviews were conducted over zoom, recorded and transcribed verbatim. Findings: Three primary themes were identified through thematic analysis: ‘flawed messaging’, ‘COVID-19 as a teachable moment’, and ‘barriers to change’. Transcending these themes was the notion of balance. Whilst the messaging around COVID-19 and obesity was deemed problematic, for some it was a teachable moment to facilitate change when their future self and physical health was prioritised. Yet, when focusing on their mental health in the present participants felt more overwhelmed by the barriers and were less likely to take the opportunity to change. Originality: This study offers a novel and useful insight into how the public health and media messaging concerning COVID-19 risk and obesity is perceived by those with overweight and obesity. Practical implications: Findings hold implications for public health messaging, highlighting the need for balance between being educational and informative but also supportive, so as to achieve maximum efficacy.

Additional publications