OBJECTIVE: To investigate whether negative implicit attitudes and beliefs toward overweight persons exist among health professionals who specialize in obesity treatment, and to compare these findings to the implicit anti-fat bias evident in the general population. DESIGN: Health care professionals completed a series of implicit and explicit attitude and belief measures. Results were compared to measures obtained from a general population sample. SUBJECTS: A total of 84 health professionals who treat obesity (71% male, mean age 48 y, mean body mass index (BMI) 25.39). MEASUREMENTS: Participants completed an attitude- and a belief-based lmplicit Association Test. This reaction time measure of automatic memory-based associations asked participants to classify words into the following target category pair. 'fat people' vs 'thin people'. Simultaneously, the tasks required categorization of words into one of the following descriptor category pairs: good vs bad (attitude measure) or motivated vs lazy (stereotype measure). Participants also reported explicit attitudes and beliefs about fat and thin persons. RESULTS: Clear evidence for implicit anti-fat bias was found for both the attitude and stereotype measures. As expected, this bias was strong but was lower than bias in the general population. Also as predicted, only minimal evidence for an explicit anti-fat bias was found. Implicit and explicit measures of the lazy stereotype were positively related although the attitude measures were not. CONCLUSION: Even health care specialists have strong negative associations toward obese persons, indicating the pervasiveness of the stigma toward obesity. Notwithstanding, there appears to be a buffering factor, perhaps related to their experience in caring for obese patients, which reduces the bias. International Journal of Obesity (2001) 25, 1525-1531 | 
