Background: The present study investigated the stigma of obesity surgery by examining whether attitudes towards a lean person can change after learning that the person used to be obese but recently lost weight either through surgery or through diet and exercise. Methods: Participants (total N = 135) initially viewed an image of a lean woman or man and rated their impression of that individual on a variety of characteristics. Participants were then shown an image of the individual before she/he lost weight and were informed that the weight loss was achieved through surgery or through diet and exercise. Participants once again rated their impressions of that individual. Results: After learning about the previous weight loss, participants rated the individual who lost weight through surgery as significantly more lazy and sloppy, less competent and sociable, less attractive, and having less healthy eating habits. The individual who lost weight through diet and exercise, in contrast, was not evaluated as harshly. Mediation analysis further showed that the difference between the two weight loss conditions in ratings of laziness, competence, and sociability was due to participants viewing surgery patients as less responsible for their weight loss. Conclusions: These findings suggest that learning about someone's weight history can negatively impact the way that person is seen by others. Furthermore, these findings suggest that the stigma may be strongest for people who lose weight through obesity surgery because those individuals are not seen as being responsible for their weight loss.