Obesity is ubiquitous in many developed countries, and it is frequently associated with health problems. Furthermore, those who are overweight or obese are frequently stigmatized in their daily lives. These issues may be exacerbated if health care workers’ impartiality is weakened owing to (unconscious) preconceptions. If pharmaceutical firms, regulatory agencies, and health insurers are also prone to similar biases, choices on the development, approval, and payment of obesity-related medicines may suffer.

The ‘Implicit Association Exam’ (IAT) was a psychometric test that evaluated these attitudes and so help uncover unconscious preferences. In the given study, a self-developed mobile version in the form of a ResearchKit-based IAT app was used. The goal was to determine (potential) weight bias and its characteristics in professionals attending a national obesity-related conference, compared to a control group (without stated interest in the topic, both using the mobile app – and a historical control based on Project Implicit data acquired via a web app.

Explicit judgments of G1 were more neutral than G2 and G3, whereas the implicit desire for lean persons did not change substantially across G2, G3, and G1. The higher disparity between the (more neutral) explicit attitude and the unconscious preference indicating an anti-obesity bias for the professional participants in G1 might imply an underestimated bias. Implicit preference was generally hard to alter because it was imprinted from birth. As a result, even experts might be influenced unintentionally in their judgments regarding the treatment they deliver. Professionals in any specific health care sector focused on obesity should be made aware of this discrepancy so that they can intentionally counteract this possible influence.