Evaluating the implementation of an eating disorder prevention programme (The Body Project) in a New Zealand tertiary environment : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Nutrition and Dietetics at Massey University, Albany, New Zealand

Abstract

Background: Body dissatisfaction is a prevalent issue among girls and young women, driven by sociocultural pressures that promote the thin ideal through social media, comparison, peers and family. Repeated exposure to these ideals can foster thin-ideal internalisation and body comparison, increasing body dissatisfaction and promoting disordered eating behaviours which may progress to clinically significant eating disorders (EDs). The Body Project is a cognitive dissonance-based prevention programme designed to reduce thin-ideal internalisation and improve body image by encouraging participants to critically challenge societal beauty standards. International research has demonstrated the programme’s efficacy in reducing body dissatisfaction, disordered eating behaviours, and the risk of ED onset in young females, but its implementation and effectiveness in New Zealand tertiary populations quantitively, has not been evaluated. This study evaluated the effectiveness of the Body Project among New Zealand female tertiary students aged 18–30 years by comparing Body Project and control groups across measures of well-being, thin-ideal internalisation, body satisfaction, disordered eating behaviours, negative affect, and psychosocial impairment. Methods: A randomised controlled trial was conducted with 68 female participants (mean age 23.6 ± 3.4 years; mean BMI 25.6 ± 6.3 kg/m²). A total of 77 participations were included in the analyses, as nine participants were re-recruited and contributed data to both study groups across different time points. Participants were randomly assigned to the Body Project (n=41) or control group (n=36). Eligible participants identified as female, were aged 18–30 years, enrolled in a New Zealand tertiary institution, and reported no current or previous ED diagnosis. The Body Project consisted of four weekly online sessions (30–70 min each) delivered in small groups (3–7 participants) by trained peer educators, incorporating verbal, written, and behavioural exercises to elicit cognitive dissonance around thin-ideal internalisation. The control group watched a 55-minute documentary, Dying to Be Thin. Pre- and post-intervention questionnaires were completed by all participants, and assessed psychological well-being (WHO-5), thin-ideal internalisation (IBSS-R), body part satisfaction (BPSS), dietary restraint (DEBQ), negative affect (PANAS-X), ED classification (EDDS), and psychosocial functioning (IPF). Results: Baseline characteristics were comparable between groups. Participants in the Body Project demonstrated greater improvements in well-being (WHO-5: 54.0 ± 16.8 to 63.7 ± 14.7; Δ = 9.7 ± 13.8) compared with the control group (58.3 ± 14.6 to 57.4 ± 17.9; Δ = –0.9 ± 13.8; p = 0.001, Cohen’s d = 0.77). Thin-ideal internalisation decreased in the Body Project group (IBSS-R: 27.1 ± 6.0 to 22.8 ± 6.7; Δ = –4.2 ± 5.9) versus the control group (27.8 ± 4.8 to 28.2 ± 5.0; Δ = 0.4 ± 4.1; p < 0.001). DEBQ items showing between-group differences included eating less at mealtimes (Δ = −1.2 vs −0.1; p = 0.001), watching exactly what was eaten (Δ = −0.6 vs 0.0; p = 0.030), deliberate consumption of slimming foods (Δ = −0.7 vs −0.1; p = 0.025), deliberately restricted eating to avoid weight gain (Δ = −0.3 vs −0.2; p = 0.033), evening food restriction (Δ = −0.9 vs 0.1; p = 0.001), and weight-based food decision-making (Δ = −0.7 vs 0.0; p = 0.019). Negative affect decreased across several PANAS-X subscales (“Dissatisfied with self,” p = 0.004; “Blue,” p = 0.032; “Angry at self,” p = 0.050). Baseline psychosocial functioning was within one standard deviation of population norms and showed no significant changes post-intervention. Conclusion: Participation in the Body Project was associated with greater reductions in thin-ideal internalisation, dietary restraint, and negative self-directed affect, as well as a greater increases in well-being and body satisfaction, compared with the control group who watched the 55-minute documentary. These findings suggest that the Body Project may be an effective evidence-based ED prevention intervention for female tertiary students in New Zealand when evaluated against an active control group.