Testing the validity of the Norwegian translation of the modified weight bias internalization scale.

Background: Individuals with higher weight (overweight or obesity) may experience social stigma due to their weight. Weight stigma can be internalized with adverse health effects. Internalized weight stigma is relevant across different weight categories, but no validated weight-neutral measure of internalized weight bias currently exists in Norway. The current study aimed to examine the validity of a Norwegian translation of the Modified Weight Bias Internalization Scale.

Methods: A Norwegian translation of the Modified Weight Bias Internalization Scale (WBIS-M) was administered in an adult Norwegian sample (N = 315, of which 251 women) ranging from self-reported "very underweight" to "very overweight".

Results: A confirmatory factor analysis was conducted on 11 of the original 11 items in the WBIS-M. Based on previous factor analyses with this scale, we expected a one-factor model. One of the items related to competence showed poor model fit, and concern was raised around possible item ambiguity partway through the study. Two versions of this item were therefore tested, neither of which yielded an acceptable fit. After exclusion of this item, the results showed high loadings for the remaining 10 items on one factor with a high internal consistency (α = 0.94). Convergent validity was approached by looking at the relationship between answers on the WBIS-M, self-perceived weight, and items on overall health and psychological/emotional state.

Conclusion: The 10-item Norwegian version of the WBIS-M shows sound psychometric properties and can be used to measure internalized weight bias in a weight-neutral fashion in a Norwegian-speaking population. Internalized weight bias was correlated with psychological/emotional state and overall health, with those reporting more internalized weight bias also reporting that they felt worse. This relationship was stronger for women than men in our sample and was partially dependent on weight. The women also showed higher internalized weight bias than the men. Future studies should include more male participants and explore alternative versions of the missing item related to competence.