Weight bias internalization, often abbreviated as WBI, describes the process by which individuals absorb the negative stereotypes, prejudice, and discrimination that circulate around body weight and then direct those beliefs inward. Rather than simply holding stigmatizing views about others, a person who has internalized weight bias engages in self-blame and self-devaluation, judging their own body through the lens of cultural assumptions that equate higher weight with laziness, poor discipline, or moral failing. In adolescence, a developmental window in which body image is consolidating and identity is still forming, psychologists consider this self-directed stigma particularly corrosive.

Most of what scientists knew about the link between internalized weight stigma and disordered eating came from cross-sectional studies, snapshots taken at a single point in time. Those designs can show that WBI and disordered eating co-occur, but they cannot establish which comes first. The new study was designed to break that ambiguity by measuring weight bias internalization at a baseline assessment and then tracking the same adolescents over two years to see whether their earlier levels of internalized stigma forecast later eating problems, even after accounting for how they were doing at the start.

The researchers drew a representative sample of adolescents from Terrassa, a city in the Barcelona metropolitan area, using random multistage cluster sampling to select participants across schools. At baseline in 2022, 1,016 adolescents completed assessments, and 551 of them returned for follow-up in 2024, an overall retention of 54.2 percent. Retention was substantially higher among participants who remained in compulsory secondary education, reaching 81.3 percent, which the authors note strengthens confidence in the representativeness of the longitudinal subsample for that group. The study received ethics approval from the Universitat Autònoma de Barcelona and followed the Declaration of Helsinki, with active parental consent and adolescent assent at baseline and participant consent at follow-up.

Weight bias internalization was measured with the WBIS-M scale, a widely used instrument that asks respondents to rate their agreement with statements reflecting self-directed weight stigma. Two years later, the team assessed a battery of outcomes: drive for thinness, body dissatisfaction, bulimic symptoms, binge eating severity, and engagement in unhealthy weight control behaviors, the latter covering strategies such as skipping meals, fasting, or other potentially harmful attempts to manage weight. The statistical models were deliberately conservative. Linear regression, multinomial logistic regression, and modified Poisson regression were all adjusted for baseline levels of the outcome being predicted, for measured weight status, and for sociodemographic variables, meaning the analyses tested whether WBI added predictive value beyond what was already known about each adolescent.

The results were consistent across outcomes. Higher weight bias internalization at baseline prospectively predicted greater disordered eating attitudes and higher overall eating disorder risk two years later, with regression coefficients ranging from 0.7 to 3.28 and p-values between 0.029 and below 0.001. The effects were especially pronounced in girls, a pattern the authors emphasize as clinically important given that girls already carry the heaviest burden of eating pathology during adolescence. The finding suggests that internalized stigma functions as a specific amplifier of risk in the group most vulnerable to it.

Two findings stand out for their magnitude and prevalence. Among girls, baseline WBI was associated with a more than twofold increase in the relative risk of severe binge eating at follow-up, with a relative risk ratio of 2.45 and a p-value of 0.001. Girls with higher internalized weight stigma were also significantly more likely to report unhealthy weight control behaviors, with a relative risk of 1.04 at p equal to 0.017. That modest relative risk translates into substantial absolute impact because the behaviors themselves are so common: 42.1 percent of the entire sample reported engaging in unhealthy weight control behaviors, rising to 55.4 percent among girls. More than half of the adolescent girls in this representative sample were, in effect, using potentially harmful methods to control their weight.

The technical strength of the design lies in its temporal separation and adjustment strategy. Because WBI was measured before the outcomes, and because the models controlled for baseline outcome levels, the associations cannot be explained by reverse causation in the simple sense, that is, by eating problems already present driving higher internalized stigma. The adjustment for measured weight status also matters, since it rules out the possibility that the association merely reflects the well-documented link between higher body weight and both stigma and eating concerns. What remains is a pathway in which the psychological experience of self-directed stigma contributes to the development of eating pathology in its own right, independent of body size.

The Mediterranean context of the sample adds weight to the findings. Research on weight stigma has been concentrated in North America and northern Europe, and there has been a genuine gap in prospective data from Mediterranean populations, where dietary culture and body image norms may differ. The Terrassa sample, representative of a mid-sized Spanish city, indicates that the mechanisms linking internalized stigma to disordered eating are not confined to Anglophone settings. The authors also point out that adolescence is a critical period for both body image development and the emergence of eating disorders, which makes longitudinal evidence from this age group especially valuable for prevention planning.

The implications reach beyond the clinic. If internalized weight stigma is a modifiable risk factor, then interventions that reduce stigma before it takes root in self-evaluation could help prevent disordered eating before it begins, rather than treating it after the fact. The authors argue that promoting supportive and inclusive attitudes toward body diversity, and moving away from framing weight as a matter of individual blame, may protect young people’s health and well-being. In practical terms, that points toward school-based programs that address stigma directly, media literacy education that counters narrow body ideals, and public health messaging that avoids the moralizing tone long shown to backfire. With more than half of adolescent girls in this sample already engaging in unhealthy weight control, the case for acting early on the stigma that feeds those behaviors is difficult to ignore.

Subject of Research: Weight bias internalization as a prospective predictor of disordered eating and unhealthy weight control behaviors in adolescents

Article Title: Weight bias internalization and risk of disordered eating and unhealthy weight control behaviors in Spanish adolescents: a two-year longitudinal study

Article References: Almazán, C., Tárrega, S., Fornieles-Deu, A., & Sánchez-Carracedo, D. (2026). Weight bias internalization and risk of disordered eating and unhealthy weight control behaviors in Spanish adolescents: a two-year longitudinal study. Journal of Eating Disorders. https://doi.org/10.1186/s40337-026-01782-9

Image Credits: AI Generated

DOI: 10.1186/s40337-026-01782-9

Keywords: weight bias internalization, weight stigma, disordered eating, unhealthy weight control behaviors, adolescents, binge eating, body dissatisfaction, longitudinal study, eating disorders, Spain, body image, prevention