OBJECTIVE:To investigate the internalization of anti-fat bias among overweight individuals across a variety of attitudes and stereotypes. DESIGN: Two studies were conducted using the Implicit Association Test (IAT), a performance-based measure of bias, to examine beliefs among overweight individuals about 'fat people' vs 'thin people'. Study two also contained explicit measures of attitudes about obese people. SUBJECTS: Study 1 participants were 68 overweight patients at a treatment research clinic (60 women, 8 men; mean Body Mass Index (BMI) of 37.173.9 kg/m 2 ). Study 2 involved 48 overweight participants (33 women, 15 men) with a BMI of 34.574.0 kg/ m 2 . RESULTS: Participants exhibited significant anti-fat bias on the IAT across several attributes and stereotypes. They also endorsed the explicit belief that fat people are lazier than thin people. CONCLUSION: Unlike other minority group members, overweight individuals do not appear to hold more favorable attitudes toward ingroup members. This ingroup devaluation has implications for changing the stigma of obesity and for understanding the psychosocial and even medical impact of obesity on those affected.