Eating disorders remain among the most psychologically devastating and costly mental health conditions affecting young women worldwide, and a growing body of evidence suggests that the most effective way to blunt their impact is to stop them before they start. Now, for the first time, researchers in Portugal have rigorously tested one of the world’s best-validated prevention programs on Portuguese soil, and the results offer both reassurance and a genuinely surprising twist about how, exactly, such programs should be delivered. The study, conducted at the University of Minho and published in the Journal of Eating Disorders, found that the Body Project—a dissonance-based group intervention—produced significant, durable improvements in body image and eating-related symptoms among Portuguese female university students, whether delivered face-to-face or over a video platform, with benefits persisting up to a full year after the sessions ended.
The Body Project rests on a deceptively simple psychological engine: cognitive dissonance. Participants, typically young women who have internalized the cultural “thin ideal”—the belief that thinness equals beauty, worth, and success—are asked to actively critique that ideal in front of peers. Across a series of structured group sessions, they verbally, physically, and creatively reject the thin ideal, role-playing conversations, writing letters, and designing mirror challenges that challenge appearance-based self-worth. The theory holds that publicly arguing against a belief you privately hold creates an uncomfortable state of dissonance, and the mind resolves that tension by genuinely shifting attitudes. Decades of trials, largely in the United States, have supported this mechanism, showing reductions in thin-ideal internalization, body dissatisfaction, dieting, and overt eating disorder symptoms. What remained uncertain was whether this culturally loaded approach—so deeply rooted in Western beauty ideals—would translate to another national context, and whether the increasingly common virtual delivery format could match the power of the traditional in-person group room.
To answer those questions, the research team led by Carol Coelho, Rita Ramos, Tânia Rodrigues, Sónia Gonçalves, and Paulo P. P. Machado recruited 147 female university students between the ages of 18 and 30, all of whom reported concerns about their bodies—an at-risk profile that prevention science targets precisely because early subclinical symptoms predict later full-syndrome disorders. Participants were randomly assigned to one of three conditions: the Body Project delivered in person by trained peer facilitators, the same protocol delivered virtually, or a waitlist control group that received no intervention during the study period but could access care afterward. Random assignment is the gold standard for isolating causal effects, and the peer-led model matters as much as the randomization: because the Body Project is designed to be delivered by trained peers rather than clinicians, it can be scaled far more cheaply across universities, schools, and community settings, which is where most at-risk young women actually are.
The measurement battery captured the constructs the program is designed to move. The researchers tracked thin-ideal internalization—the psychological bedrock the intervention targets—alongside dieting behaviors, eating disorder symptomatology, negative affect, body appreciation, and self-esteem, assessed before the intervention, immediately after it, and at both six-month and twelve-month follow-ups. Compared with the waitlist control, both the in-person and virtual groups showed statistically significant improvements from pre- to posttest across nearly the entire outcome set. Participants reported high satisfaction with the program in both formats, an important practical finding since satisfaction predicts engagement, adherence, and word-of-mouth recruitment in real-world dissemination. The lone exception at posttest was self-esteem in the virtual group, which did not significantly improve relative to controls—a nuance that hints the digital format may take longer to build the interpersonal momentum that underpins some of the program’s broader psychological gains.
The durability of the effects is arguably the study’s most consequential result. At six months, improvements remained significant across outcomes in both intervention groups. At twelve months, most gains still held, with two exceptions: negative affect and dieting behaviors in the in-person group were no longer significantly different from baseline patterns at that final follow-up. In prevention science, where programs are often judged by whether they can bend trajectories years before a disorder would otherwise emerge, a year of maintained benefit from a brief, peer-led intervention is a strong showing. Eating disorders typically develop during adolescence and young adulthood, carry elevated medical risk, and impose substantial personal and societal costs, so a short program that durably shifts risk factors represents an efficient public health investment.
But the headline finding that distinguishes this trial from its predecessors lies in the timing and structure of how the two delivery modalities worked. Overall, both formats produced comparable outcomes—yet they got there differently. The in-person group showed larger immediate reductions in eating disorder symptomatology right after the program ended, while the virtual group’s reductions in eating-related problems arrived later, suggesting a delayed but ultimately equivalent therapeutic trajectory. The researchers interpret this as evidence that face-to-face group cohesion may accelerate dissonance-driven attitude change, while virtual groups may require more time for participants to feel safe enough to engage in the emotionally exposing work of publicly rejecting the thin ideal through a screen. For program planners, the practical implication is that virtual delivery is a legitimate and effective option, not a compromise, provided that expectations about the pace of change are calibrated accordingly.
The study’s second pioneering contribution concerns preference matching—whether it matters if participants receive the delivery format they actually wanted. Until now, no published trial had examined whether matching participants to their preferred modality moderates the outcomes of a dissonance-based prevention program. Here, the answer was a clear yes: preference match significantly moderated the effect of delivery modality on changes from pre- to posttest in four key outcomes—thin-ideal internalization, dieting behaviors, eating disorder symptomatology, and body appreciation. The pattern, explored in secondary analyses, was unexpectedly asymmetrical. Participants who received their preferred format tended to show larger gains in the in-person condition, whereas participants who did not get their preferred format tended to show larger gains in the virtual condition. The authors note these analyses were exploratory, and the underlying mechanism is not yet clear—perhaps unmatched participants in the virtual condition compensated with greater engagement, or perhaps different motivational profiles sort into different preferences in ways that interact with the group environment.
Beyond its immediate findings, the trial carries weight as a cross-cultural validation. The Body Project’s scripts and exercises assume participants navigate a media environment saturated with thin-ideal imagery, but the specific content of that imagery, and the social scripts around discussing it, vary across cultures. Demonstrating efficacy in Portugal—a Southern European context with distinct beauty norms and healthcare structures—extends the program’s evidence base beyond its Anglophone origins and joins a small but growing set of international replications, including prior work with Brazilian girls. It also demonstrates feasibility: the program was delivered by graduate students in the university’s Eating Disorders Research Group, supporting the premise that non-specialist facilitators can run it faithfully. The work was conducted at the Psychology Research Centre (CIPsi) at the School of Psychology, University of Minho, and funded by the Portuguese Foundation for Science and Technology, with ethics approval from the university’s research ethics committee and informed consent obtained from all participants.
The findings arrive at a moment when virtual mental health delivery has shifted from pandemic-era necessity to permanent fixture of care, and when young women—exposed to appearance-focused social media algorithms from adolescence—are widely considered a priority population for prevention. The Portuguese results suggest health systems need not choose between reach and rigor: a virtual Body Project can extend prevention to students who cannot or will not attend in-person groups, while in-person delivery may offer faster symptom relief for those who can access it. The preference-matching results add an intriguing and clinically actionable layer, hinting that simply asking participants about their delivery preferences before randomizing or assigning them could sharpen outcomes, though the asymmetrical pattern means the optimal matching strategy is not yet obvious and warrants replication in larger, more diverse samples.
The authors are candid about the study’s limitations. The sample consisted exclusively of female university students with body concerns at a single Portuguese institution, which constrains generalization to men, to adolescents, to clinical populations, and to community settings. The waitlist control design, while appropriate for establishing initial efficacy, cannot account for nonspecific factors such as time, attention, and expectancy in the way an active control or credible placebo condition could. Self-report measures dominate the outcome battery, leaving room for reporting biases. And the exploratory nature of the preference-match analyses means those findings should be treated as hypothesis-generating rather than definitive. Still, the core conclusions—that the Body Project works in Portugal, that it works virtually as well as in person over the long run, and that what participants prefer may meaningfully shape how much they benefit—stand on a methodologically solid randomized foundation.
For a field in which treatment of established eating disorders remains difficult, expensive, and often only partially effective, prevention programs that are brief, peer-led, culturally portable, and deliverable through a laptop camera represent a rare combination of scalability and proven impact. This first Portuguese trial of the Body Project confirms that the dissonance mechanism travels across borders and screens alike—and it opens a new line of inquiry into how a simple question, “which format would you prefer?”, might become a low-cost tool for amplifying prevention’s already impressive returns.
Subject of Research: Efficacy and feasibility of the dissonance-based Body Project eating disorder prevention program in Portugal, comparing in-person and virtual delivery and the role of participant preference match
Subject of Research: Medicine
Article Title: Dissonance-based eating disorder prevention for young women in Portugal: examining the body project’s efficacy, delivery modality, and preference match
Article References: Coelho, C., Ramos, R., Rodrigues, T., Gonçalves, S., & Machado, P. P. P. (2026). Dissonance-based eating disorder prevention for young women in Portugal: examining the body project’s efficacy, delivery modality, and preference match. Journal of Eating Disorders. https://doi.org/10.1186/s40337-026-01711-w
Image Credits: AI Generated
DOI: 10.1186/s40337-026-01711-w
Keywords: eating disorders, dissonance-based prevention, Body Project, delivery modality, preference match, risk factors, protective factors, body image, cross-cultural validation, young women, virtual intervention, Portugal
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Ophelia Keating. (September 11, 2026). Body Project program shows promise for preventing eating disorders in Portuguese women. Scienmag. https://scienmag.com/body-project-program-shows-promise-for-preventing-eating-disorders-in-portuguese-women/
Ophelia Keating. “Body Project program shows promise for preventing eating disorders in Portuguese women.” Scienmag, 11 September 2026, https://scienmag.com/body-project-program-shows-promise-for-preventing-eating-disorders-in-portuguese-women/. Accessed 11 September 2026.
Ophelia Keating. “Body Project program shows promise for preventing eating disorders in Portuguese women.” Scienmag. September 11, 2026. https://scienmag.com/body-project-program-shows-promise-for-preventing-eating-disorders-in-portuguese-women/
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